阅读说明：本技术 用于dft扩展ofdm的低papr dmrs和低小区间干扰 (Low PAPR DMRS and low inter-cell interference for DFT spread OFDM ) 是由 阿尔凡·沙欣 李文一 杨瑞 于 2019-12-31 设计创作，主要内容包括：WTRU可以包括被配置成确定用于PI/2BPSK DFT-s-OFDM调制的长度为12、18和24的DMRS序列的电路。所述序列针对PAPR、CM、频率平坦度、互相关和信道估计(循环相关)而被优化。(The WTRU may include circuitry configured to determine DMRS sequences of lengths 12, 18, and 24 for PI/2BPSK DFT-s-OFDM modulation. The sequence is optimized for PAPR, CM, frequency flatness, cross-correlation, and channel estimation (cyclic correlation).)

1. A wireless transmit/receive unit (WTRU), comprising:

circuitry configured to determine a sequence from a set of sequences comprising 000000110110, 000001000111, and 000001110111; and

a transmitter configured to transmit a demodulation reference signal (DMRS) derived from the determined sequence.

2. The WTRU of claim 1, wherein the determined sequence is 000000110110.

3. The WTRU of claim 1, wherein the determined sequence is 000001000111.

4. The WTRU of claim 1, wherein the determined sequence is 000001110111.

5. A wireless transmit/receive unit (WTRU), comprising:

circuitry configured to determine a sequence from a set of sequences comprising: 000000011111001001, 000001000111110001, and 000001111011101111; and

a transmitter configured to transmit a demodulation reference signal (DMRS) derived from the determined sequence.

6. The WTRU of claim 5, wherein the determined sequence is 000000011111001001.

7. The WTRU of claim 5, wherein the determined sequence is 000001000111110001.

8. The WTRU of claim 5, wherein the determined sequence is 000001111011101111.

9. A wireless transmit/receive unit (WTRU), comprising:

circuitry configured to determine a sequence from a set of sequences comprising: 000000010011111001001001, 000000001101100101011011, 000000001001001001111011, and 000000010010110111000110; and

a transmitter configured to transmit a demodulation reference signal (DMRS) derived from the determined sequence.

10. The WTRU of claim 9, wherein the determined sequence is 000000010011111001001001.

11. The WTRU of claim 9, wherein the determined sequence is 000000001101100101011011.

12. The WTRU of claim 9, wherein the determined sequence is 000000001001001001111011.

13. The WTRU of claim 9, wherein the determined sequence is 000000001001001001111011000000010010110111000110.

Disclosure of Invention

A wireless transmit/receive unit (WTRU) may include circuitry configured to determine a sequence from a set of sequences including 000000110110, 000001000111, and 000001110111. The WTRU may also include a transmitter configured to transmit a demodulation reference signal (DMRS) derived from the determined sequence.

Drawings

Further, wherein like reference numerals refer to like elements throughout, and wherein:

FIG. 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented;

figure 1B is a system diagram illustrating an example wireless transmit/receive unit (WTRU) that may be used within the communication system shown in figure 1A, according to one embodiment;

fig. 1C is a system diagram illustrating an example Radio Access Network (RAN) and an example Core Network (CN) that may be used within the communication system shown in fig. 1A, according to one embodiment;

figure 1D is a system diagram illustrating another exemplary RAN and another exemplary CN that may be used within the communication system shown in figure 1A according to one embodiment;

FIG. 2 is a diagram of two different implementations of a pi/2 Binary Phase Shift Keying (BPSK) Discrete Fourier Transform (DFT) spread Orthogonal Frequency Division Multiplexing (OFDM) with Frequency Domain Spectral Shaping (FDSS);

FIG. 3 is a diagram of an example time and frequency structure of type 1;

fig. 4 is a block diagram illustrating an example transmitter for demodulating a reference signal (DMRS); and

fig. 5 is a block diagram illustrating an example transmitter for generating DMRS signals without losing properties of a set of sequences.

Exemplary network for implementation of embodiments

Fig. 1A is a schematic diagram illustrating an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple-access system that provides content, such as voice, data, video, messaging, broadcast, etc., to a plurality of wireless users. The communication system 100 may enable multiple wireless users to access such content by sharing system resources, including wireless bandwidth. For example, communication system 100 may use one or more channel access methods such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), orthogonal FDMA (ofdma), single carrier FDMA (SC-FDMA), zero-tailed unique word discrete fourier transform-spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, and filter bank multi-carrier (FBMC), among others.

As shown in fig. 1A, the communication system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a Radio Access Network (RAN)104, a Core Network (CN)106, a Public Switched Telephone Network (PSTN)108, the internet 110, and other networks 112, although it should be appreciated that any number of WTRUs, base stations, networks, and/or network components are contemplated by the disclosed embodiments. The WTRUs 102a, 102b, 102c, 102d may each be any type of device configured to operate and/or communicate in a wireless environment. For example, any of the WTRUs 102a, 102b, 102c, 102d may be referred to as a Station (STA), which may be configured to transmit and/or receive wireless signals, and may include a User Equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a Personal Digital Assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an internet of things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., tele-surgery), industrial devices and applications (e.g., robots, and/or other wireless devices operating in an industrial and/or automated processing chain environment), consumer electronics devices and applications (e.g., robots, other wireless devices operating in an industrial and/or automated processing chain environment), and/or other wireless devices, And devices operating on commercial and/or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c, 102d may be referred to interchangeably as a UE.

The communication system 100 may also include a base station 114a and/or a base station 114 b. Each of the base stations 114a, 114b may be any type of device configured to facilitate access to one or more communication networks (e.g., the CN 106, the internet 110, and/or other networks 112) by wirelessly interfacing with at least one of the WTRUs 102a, 102b, 102c, 102 d. For example, the base stations 114a, 114B may be Base Transceiver Stations (BTSs), nodes B, e node bs (enbs), home node bs, home enodebs, next generation node bs (such as the gNB), New Radio (NR) node bs, site controllers, Access Points (APs), and wireless routers, among others. Although each of the base stations 114a, 114b is depicted as a single component, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and/or network components.

The base station 114a may be part of the RAN 104, and the RAN may also include other base stations and/or network components (not shown), such as Base Station Controllers (BSCs), Radio Network Controllers (RNCs), relay nodes, and so forth. Base station 114a and/or base station 114b may be configured to transmit and/or receive wireless signals on one or more carrier frequencies, known as cells (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide wireless service coverage for a particular geographic area that is relatively fixed or may vary over time. The cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., each transceiver corresponding to a sector of a cell. In an embodiment, base station 114a may use multiple-input multiple-output (MIMO) technology and may use multiple transceivers for each sector of a cell. For example, using beamforming, signals may be transmitted and/or received in desired spatial directions.

The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., Radio Frequency (RF), microwave, centimeter-wave, millimeter-wave, Infrared (IR), Ultraviolet (UV), visible, etc.). Air interface 116 may be established using any suitable Radio Access Technology (RAT).

More specifically, as described above, communication system 100 may be a multiple-access system and may use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA, among others. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) terrestrial radio access (UTRA), which may use wideband cdma (wcdma) to establish the air interface 116. WCDMA may include communication protocols such as High Speed Packet Access (HSPA) and/or evolved HSPA (HSPA +). HSPA may include high speed Downlink (DL) packet access (HSDPA) and/or High Speed UL Packet Access (HSUPA).

In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as evolved UMTS terrestrial radio access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and/or LTE-advanced (LTE-a) and/or LTE-Pro (LTE-a Pro).

In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement some radio technology that may establish the air interface 116 using NR, such as NR radio access.

In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may collectively implement LTE radio access and NR radio access (e.g., using Dual Connectivity (DC) principles). As such, the air interface used by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and/or transmissions sent to/from multiple types of base stations (e.g., eNB and gNB).

In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless high fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA 20001X, CDMA2000 EV-DO, interim standard 2000(IS-2000), interim standard 95(IS-95), interim standard 856(IS-856), Global System for Mobile communications (GSM), enhanced data rates for GSM evolution (EDGE), and GSM EDGE (GERAN), among others.

The base station 114B in fig. 1A may be, for example, a wireless router, a home nodeb, a home enodeb, or an access point, and may facilitate wireless connectivity in a local area using any suitable RAT, such as a business, a residence, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by a drone), and a road, among others. In one embodiment, the base station 114b and the WTRUs 102c, 102d may establish a Wireless Local Area Network (WLAN) by implementing a radio technology such as IEEE 802.11. In an embodiment, the base station 114b and the WTRUs 102c, 102d may establish a Wireless Personal Area Network (WPAN) by implementing a radio technology such as IEEE 802.15. In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may establish the pico cell or the femto cell by using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE-A, LTE-a Pro, NR, etc.). As shown in fig. 1A, the base station 114b may be directly connected to the internet 110. Thus, the base station 114b need not access the internet 110 via the CN 106.

The RAN 104 may communicate with a CN 106, which may be any type of network configured to provide voice, data, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102 d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, fault tolerance requirements, reliability requirements, data throughput requirements, and mobility requirements, among others. The CN 106 may provide call control, billing services, mobile location-based services, prepaid calling, internet connectivity, video distribution, etc., and/or may perform high-level security functions such as user authentication. Although not shown in fig. 1A, it should be appreciated that the RAN 104 and/or the CN 106 may communicate directly or indirectly with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104 using NR radio technology, the CN 106 may communicate with another RAN (not shown) using GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technologies.

The CN 106 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the internet 110, and/or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides Plain Old Telephone Service (POTS). The internet 110 may include a system of globally interconnected computer network devices that utilize common communication protocols, such as transmission control protocol/internet protocol (TCP), User Datagram Protocol (UDP), and/or IP in the TCP/IP internet protocol suite. The network 112 may include wired or wireless communication networks owned and/or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may use the same RAT as the RAN 104 or a different RAT.

Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers that communicate with different wireless networks over different wireless links). For example, the WTRU 102c shown in fig. 1A may be configured to communicate with a base station 114a using a cellular-based radio technology and with a base station 114b, which may use an IEEE 802 radio technology.

Figure 1B is a system diagram illustrating an exemplary WTRU 102. As shown in fig. 1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive component 122, a speaker/microphone 124, a keypad 126, a display/touch pad 128, non-removable memory 130, removable memory 132, a power source 134, a Global Positioning System (GPS) chipset 136, and/or peripherals 138. It should be appreciated that the WTRU 102 may include any subcombination of the foregoing components while maintaining consistent embodiments.

The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a Digital Signal Processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), any other type of Integrated Circuit (IC), a state machine, or the like. The processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to a transceiver 120 and the transceiver 120 may be coupled to a transmit/receive component 122. Although fig. 1B depicts processor 118 and transceiver 120 as separate components, it should be understood that processor 118 and transceiver 120 may be integrated together in an electronic component or chip.

The transmit/receive component 122 may be configured to transmit or receive signals to or from a base station (e.g., base station 114a) via the air interface 116. For example, in one embodiment, the transmit/receive component 122 may be an antenna configured to transmit and/or receive RF signals. As an example, in another embodiment, the transmit/receive component 122 may be an emitter/detector configured to emit and/or receive IR, UV or visible light signals. In yet another embodiment, the transmit/receive component 122 may be configured to transmit and/or receive RF and optical signals. It should be appreciated that the transmit/receive component 122 may be configured to transmit and/or receive any combination of wireless signals.

Although transmit/receive component 122 is depicted in fig. 1B as a single component, WTRU 102 may include any number of transmit/receive components 122. More specifically, the WTRU 102 may use MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit/receive components 122 (e.g., multiple antennas) that transmit and receive wireless signals over the air interface 116.

Transceiver 120 may be configured to modulate signals to be transmitted by transmit/receive element 122 and to demodulate signals received by transmit/receive element 122. As described above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers that allow the WTRU 102 to communicate via multiple RATs (e.g., NR and IEEE 802.11).

The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker/microphone 124, a keypad 126, and/or a display/touch pad 128, such as a Liquid Crystal Display (LCD) display unit or an Organic Light Emitting Diode (OLED) display unit. The processor 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128. Further, processor 118 may access information from and store information in any suitable memory, such as non-removable memory 130 and/or removable memory 132. The non-removable memory 130 may include Random Access Memory (RAM), Read Only Memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a Subscriber Identity Module (SIM) card, a memory stick, a Secure Digital (SD) memory card, and so forth. In other embodiments, the processor 118 may access information from and store data in memory that is not physically located in the WTRU 102, such memory may be located, for example, in a server or a home computer (not shown).

The processor 118 may receive power from the power source 134 and may be configured to distribute and/or control power for other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (Ni-Cd), nickel-zinc (Ni-Zn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), solar cells, and fuel cells, among others.

The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) related to the current location of the WTRU 102. In addition to or in lieu of information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) via the air interface 116 and/or determine its location based on the timing of signals received from two or more nearby base stations. It should be appreciated that the WTRU 102 may acquire location information via any suitable positioning method while maintaining consistent embodiments.

The processor 118 may also be coupled to other peripheral devices 138, which may include one or more software and/or hardware modules that provide additional features, functionality, and/or wired or wireless connections. For example, the peripheral devices 138 may include accelerometers, electronic compasses, satellite transceivers, digital cameras (for photos and/or video), Universal Serial Bus (USB) ports, vibration devices, television transceivers, hands-free headsets, portable telephones, and the like,Modules, Frequency Modulation (FM) radio units, digital music players, media players, video game modules, internet browsers, virtual reality and/or augmented reality (VR/AR) devices, and activity trackers, among others. The peripheral device 138 may include one or more sensors. The sensor may be one or more of: gyroscopes, accelerometers, hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time sensors, geographic position sensors, altimeters, light sensors, touch sensors, magnetometers, barometers, gesture sensors, biometric sensors, and humidity sensors, among others.

The WTRU 102 may include a full duplex radio for which reception or transmission of some or all signals (e.g., associated with particular subframes for UL (e.g., for transmission) and DL (e.g., for reception)) may be concurrent and/or simultaneous. The full-duplex radio may include an interference management unit that reduces and/or substantially eliminates self-interference via signal processing by hardware (e.g., a choke coil) or by a processor (e.g., a separate processor (not shown) or by the processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio that transmits and receives some or all signals (e.g., associated with a particular subframe for UL (e.g., for transmission) or DL (e.g., for reception)).

Figure 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As described above, the RAN 104 may communicate with the WTRUs 102a, 102b, 102c using E-UTRA radio technology over the air interface 116. The RAN 104 may also communicate with a CN 106.

RAN 104 may include enodebs 160a, 160B, 160c, however, it should be appreciated that RAN 104 may include any number of enodebs while maintaining consistent embodiments. The enodebs 160a, 160B, 160c may each include one or more transceivers that communicate with the WTRUs 102a, 102B, 102c over the air interface 116. In one embodiment, the enodebs 160a, 160B, 160c may implement MIMO technology. Thus, for example, the enodeb 160a may use multiple antennas to transmit wireless signals to the WTRU 102a and/or to receive wireless signals from the WTRU 102 a.

The enodebs 160a, 160B, 160c may each be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and/or DL, and so forth. As shown in FIG. 1C, eNode Bs 160a, 160B, 160C may communicate with each other over an X2 interface.

The CN 106 shown in fig. 1C may include a Mobility Management Entity (MME)162, a Serving Gateway (SGW)164, and a Packet Data Network (PDN) gateway (PGW) 166. While the foregoing components are described as being part of the CN 106, it should be appreciated that any of these components may be owned and/or operated by an entity other than the CN operator.

The MME 162 may be connected to each of the enodebs 160a, 160B, 160c in the RAN 104 via an S1 interface and may act as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, performing bearer activation/deactivation processes, and selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, 102c, among other things. MME 162 may provide a control plane function for switching between RAN 104 and other RANs (not shown) that use other radio technologies (e.g., GSM and/or WCDMA).

The SGW 164 may be connected to each of the enodebs 160a, 160B, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102 c. The SGW 164 may also perform other functions such as anchoring the user plane during inter-eNB handovers, triggering paging processing when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

The SGW 164 may be connected to a PGW 146, which may provide packet-switched network (e.g., internet 110) access for the WTRUs 102a, 102b, 102c to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to a circuit-switched network (e.g., the PSTN 108) to facilitate communications between the WTRUs 102a, 102b, 102c and conventional landline communication devices. For example, the CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server), and the IP gateway may serve as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks owned and/or operated by other service providers.

Although the WTRU is depicted in fig. 1A-1D as a wireless terminal, it is contemplated that in some representative embodiments, such a terminal may use a (e.g., temporary or permanent) wired communication interface with a communication network.

In a representative embodiment, the other network 112 may be a WLAN.

A WLAN in infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more Stations (STAs) associated with the AP. The AP may access or interface to a Distribution System (DS) or other type of wired/wireless network that carries traffic into and/or out of the BSS. Traffic originating outside the BSS and destined for the STAs may arrive through the AP and be delivered to the STAs. Traffic originating from the STAs and destined for destinations outside the BSS may be sent to the AP for delivery to the respective destinations. Traffic between STAs within the BSS may be transmitted through the AP, for example, under conditions where the source STA may transmit traffic to the AP and the AP may deliver the traffic to the destination STA. Traffic between STAs within the BSS may be considered and/or referred to as point-to-point traffic. The point-to-point traffic may be transmitted between (e.g., directly between) the source and destination STAs using Direct Link Setup (DLS). In certain representative embodiments, DLS may use 802.11e DLS or 802.11z channelized DLS (tdls)). For example, a WLAN using an Independent Bss (IBSS) mode has no AP, and STAs (e.g., all STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "Ad-hoc" communication mode.

When using the 802.11ac infrastructure mode of operation or similar mode of operation, the AP may transmit a beacon on a fixed channel (e.g., a primary channel). The primary channel may have a fixed width (e.g., 20MHz bandwidth) or a dynamically set width. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In some representative embodiments, implemented may be carrier sense multiple access with collision avoidance (CSMA/CA) (e.g., in 802.11 systems). For CSMA/CA, STAs (e.g., each STA) including the AP may sense the primary channel. A particular STA may back off if it senses/detects and/or determines that the primary channel is busy. In a given BSS, there is one STA (e.g., only one station) transmitting at any given time.

High Throughput (HT) STAs may communicate using 40MHz wide channels (e.g., 40MHz wide channels formed by combining a20 MHz wide primary channel with 20MHz wide adjacent or non-adjacent channels).

Very High Throughput (VHT) STAs may support channels that are 20MHz, 40MHz, 80MHz, and/or 160MHz wide. 40MHz and/or 80MHz channels may be formed by combining consecutive 20MHz channels. The 160MHz channel may be formed by combining 8 consecutive 20MHz channels or by combining two discontinuous 80MHz channels (this combination may be referred to as an 80+80 configuration). For the 80+80 configuration, after channel encoding, the data may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time domain processing may be performed separately on each stream. The streams may be mapped on two 80MHz channels and data may be transmitted by STAs performing the transmissions. At the receiver of the STA performing the reception, the above-described operations for the 80+80 configuration may be reversed, and the combined data may be transmitted to a Medium Access Control (MAC).

802.11af and 802.11ah support operating modes below 1 GHz. The use of channel operating bandwidths and carriers in 802.11af and 802.11ah is reduced compared to 802.11n and 802.11 ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV white space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. In accordance with a representative embodiment, 802.11ah may support meter type control/Machine Type Communication (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, such as limited capabilities including supporting (e.g., supporting only) certain and/or limited bandwidth. The MTC device may include a battery, and the battery life of the battery is above a threshold (e.g., to maintain a long battery life).

For WLAN systems (e.g., 802.11n, 802.11ac, 802.11af, and 802.11ah) that can support multiple channels and channel bandwidths, these systems contain channels that can be designated as primary channels. The bandwidth of the primary channel may be equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and/or limited by a STA that is sourced from all STAs operating in the BSS supporting the minimum bandwidth operating mode. In an example for 802.11ah, even though the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and/or other channel bandwidth operating modes, the width of the primary channel may be 1MHz for STAs (e.g., MTC-type devices) that support (e.g., only support) 1MHz mode. Carrier sensing and/or Network Allocation Vector (NAV) setting may depend on the state of the primary channel. If the primary channel is busy (e.g., because STAs (which support only 1MHz mode of operation) transmit to the AP), all available bands may be considered busy even if most of the available bands remain idle.

In the united states, the available frequency band available for 802.11ah is 902MHz to 928 MHz. In korea, the available frequency band is 917.5MHz to 923.5 MHz. In Japan, the available frequency band is 916.5MHz to 927.5 MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, in accordance with the country code.

Figure 1D is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As described above, the RAN 104 may communicate with the WTRUs 102a, 102b, 102c using NR radio technology over the air interface 116. The RAN 104 may also communicate with the CN 106.

RAN 104 may include gnbs 180a, 180b, 180c, but it should be appreciated that RAN 104 may include any number of gnbs while maintaining consistent embodiments. The gnbs 180a, 180b, 180c may each include one or more transceivers to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gnbs 180a, 180b, 180c may implement MIMO techniques. For example, the gnbs 180a, 180b may use beamforming processing to transmit and/or receive signals to and/or from the gnbs 180a, 180b, 180 c. Thus, for example, the gNB 180a may use multiple antennas to transmit wireless signals to the WTRU 102a and to receive wireless signals from the WTRU 102 a. In an embodiment, the gnbs 180a, 180b, 180c may implement carrier aggregation techniques. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on the unlicensed spectrum, while the remaining component carriers may be on the licensed spectrum. In an embodiment, the gnbs 180a, 180b, 180c may implement coordinated multipoint (CoMP) techniques. For example, WTRU 102a may receive a cooperative transmission from gNB 180a and gNB 180b (and/or gNB 180 c).

The WTRUs 102a, 102b, 102c may communicate with the gnbs 180a, 180b, 180c using transmissions associated with a scalable digital configuration. For example, the OFDM symbol spacing and/or OFDM subcarrier spacing may be different for different transmissions, different cells, and/or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gnbs 180a, 180b, 180c using subframes or Transmission Time Intervals (TTIs) having different or scalable lengths (e.g., including different numbers of OFDM symbols and/or lasting different absolute time lengths).

The gnbs 180a, 180b, 180c may be configured to communicate with WTRUs 102a, 102b, 102c in independent configurations and/or non-independent configurations. In a standalone configuration, the WTRUs 102a, 102B, 102c may communicate with the gnbs 180a, 180B, 180c without accessing other RANs (e.g., enodebs 160a, 160B, 160 c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gnbs 180a, 180b, 180c as mobility anchors. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gnbs 180a, 180b, 180c using signals in an unlicensed frequency band. In a non-standalone configuration, the WTRUs 102a, 102B, 102c may communicate/connect with the gnbs 180a, 180B, 180c while communicating/connecting with other RANs (e.g., enodebs 160a, 160B, 160 c). For example, the WTRUs 102a, 102B, 102c may communicate with one or more gnbs 180a, 180B, 180c and one or more enodebs 160a, 160B, 160c in a substantially simultaneous manner by implementing DC principles. In a non-standalone configuration, the enode bs 160a, 160B, 160c may serve as mobility anchors for the WTRUs 102a, 102B, 102c, and the gnbs 180a, 180B, 180c may provide additional coverage and/or throughput to serve the WTRUs 102a, 102B, 102 c.

The gnbs 180a, 180b, 180c may each be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and/or DL, support network slicing, DC, implement interworking processing between NR and E-UTRA, route user plane data to User Plane Functions (UPFs) 184a, 184b, and route control plane information to access and mobility management functions (AMFs) 182a, 182b, among other things. As shown in fig. 1D, the gnbs 180a, 180b, 180c may communicate with each other over an Xn interface.

The CN 106 shown in fig. 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF)183a, 183b, and possibly a Data Network (DN)185a, 185 b. While the foregoing components are described as being part of the CN 106, it should be appreciated that any of these components may be owned and/or operated by an entity other than the CN operator.

The AMFs 182a, 182b may be connected to one or more of the gnbs 180a, 180b, 180c in the RAN 104 via an N2 interface and may act as control nodes. For example, the AMFs 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling different Protocol Data Unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating non-access stratum (NAS) signaling, and mobility management, among others. The AMFs 182a, 182b may use network slicing to customize the CN support provided for the WTRUs 102a, 102b, 102c based on the type of service used by the WTRUs 102a, 102b, 102 c. As an example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced large-scale mobile broadband (eMBB) access, services for MTC access, and so on. The AMFs 182a, 182b may provide control plane functionality for switching between the RAN 104 and other RANs (not shown) that use other radio technologies (e.g., LTE-A, LTE-a Pro, and/or non-3 GPP access technologies such as WiFi).

The SMFs 183a, 183b may be connected to the AMFs 182a, 182b in the CN 106 via an N11 interface. The SMFs 183a, 183b may also be connected to UPFs 184a, 184b in the CN 106 via an N4 interface. The SMFs 183a, 183b may select and control the UPFs 184a, 184b, and may configure traffic routing through the UPFs 184a, 184 b. SMFs 183a, 183b may perform other functions such as managing and assigning UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing downlink data notification, among others. The PDU session type may be IP-based, non-IP-based, and ethernet-based, among others.

The UPFs 184a, 184b may connect one or more of the gnbs 180a, 180b, 180c in the RAN 104 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to a packet-switched network (e.g., the internet 110) to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices, and the UPFs 184, 184b may perform other functions, such as routing and forwarding packets, implementing user-plane policies, supporting multi-homed PDU sessions, processing user-plane QoS, buffering DL packets, and providing mobility anchoring processing, among others.

The CN 106 may facilitate communications with other networks. For example, the CN 106 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and/or wireless networks owned and/or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may connect to the DNs 185a, 185b through UPFs 184a, 184b via an N3 interface that interfaces to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the local DNs 185a, 185 b.

In view of fig. 1A-1D and the corresponding description with respect to fig. 1A-1D, one or more or all of the functions described herein with respect to one or more of the following may be performed by one or more emulation devices (not shown): WTRUs 102a-d, base stations 114a-B, enode bs 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMFs 182a-B, UPFs 184a-B, SMFs 183a-B, DNs 185 a-B, and/or any other device(s) described herein. These emulation devices can be one or more devices configured to simulate one or more or all of the functions described herein. These emulation devices may be used, for example, to test other devices and/or to simulate network and/or WTRU functions.

The simulation device may be designed to conduct one or more tests on other devices in a laboratory environment and/or in a carrier network environment. For example, the one or more simulated devices may perform one or more or all functions while implemented and/or deployed, in whole or in part, as part of a wired and/or wireless communication network in order to test other devices within the communication network. The one or more emulation devices can perform one or more or all functions while temporarily implemented or deployed as part of a wired and/or wireless communication network. The simulation device may be directly coupled to another device to perform testing and/or perform testing using over-the-air wireless communication.

The one or more emulation devices can perform one or more functions, including all functions, while not being implemented or deployed as part of a wired and/or wireless communication network. For example, the simulation device may be used in a test scenario of a test laboratory and/or an undeployed (e.g., tested) wired and/or wireless communication network to conduct testing with respect to one or more components. The one or more simulation devices may be test devices. The simulation device may transmit and/or receive data using direct RF coupling and/or wireless communication via RF circuitry (e.g., the circuitry may include one or more antennas).

Detailed Description

One way to improve the coverage of radio telecommunications is to reduce the peak-to-average power ratio (PAPR) or Cubic Metric (CM) of the transmitted signal by using Discrete Fourier Transform (DFT) -spread Orthogonal Frequency Division Multiplexing (OFDM) with pi/2-BPSK modulation and Frequency Domain Spectral Shaping (FDSS).

Fig. 2 is an illustration of two different implementations 200, 220 of pi/2 Binary Phase Shift Keying (BPSK) Discrete Fourier Transform (DFT) spread Orthogonal Frequency Division Multiplexing (OFDM) with Frequency Domain Spectral Shaping (FDSS). In a first block diagram 200, a bit 202 is modulated with pi/2-BPSK modulation 204. The pi/2-BPSK modulation 204 may be a function of previous elements in the sequence, or it may be independent of other elements. In some implementations, the pi/2-BPSK modulation is defined as shown in equation 1 below.

In the above equation, s (b)_i) Is pi/2-BPSK, symbol b_iIs the ith symbol in the sequence and i-0 corresponds to the first element of the sequence. After modulation, the generated modulation symbols may be precoded with a length-M DFT 206. Next, for the FDSS operation 208, each element of the precoding vector is multiplied by a weight determined by the filter. For example, if the filter coefficient is [ 0.2810.28 ]]Then the weight can be obtained as DFT ([ 10.280 ]_1,M-3 0.28]M), where DFT (a, M) is an M-point DFT of vector a and 0_M,KIs a zero matrix with M rows and K columns. After the FDSS operation, the inverse dft (idft)210 of the shaped precoding vector is calculated, and the resulting vector may be transmitted through the RF chain.

In the second block diagram 220 of fig. 2, bits 222 are modulated 224, FDSS operations 226 are performed, and then precoding 228 with DFT occurs. In contrast to the first block diagram 200, the second block diagram 220 implements the FDSS 226 in the time domain. In this manner, after the modulation symbols are generated 224, the modulation symbols are circularly convolved with the filter coefficients. For example, the modulation symbol is compared with [ 10.280 ]_M-3,1 0.28]And (4) circularly convolving. The main benefit of this scheme may lead to improvements in PAPR and CM performance. An IDFT is computed 230 and the resulting vector may be transmitted over the RF chain.

In some implementations, an interleaved demodulation reference signal (DMRS) structure is employed for a data-sharing channel based on pi/2-BPSK DFT-spread OFDM, which may be referred to as type 1. The data-shared channel may include a downlink-shared channel (DL-SCH) and an uplink-shared channel (UL-SCH). Other shared channels may also be used.

Fig. 3 is a diagram illustrating two mappings 300, 330 for an example time and frequency structure of type 1. For example, fig. 3 shows an example type 1DMRS mapping 300 for 1 symbol and an example type 1DMRS mapping 330 for 2 symbols. In this structure, DMRSs for two WTRUs (i.e., DMRS for WTRU1 and DMRS for WTRU 2) may be interleaved over frequency. Depending on the number of symbols, the same structure may be repeated in time (as shown in the mapping 330 for 2 symbols) to achieve better channel estimation. In one embodiment, the DMRSs for WTRU1 and WTRU2 may be orthogonal to each other in frequency as shown, or alternatively or in combination in time.

In the example mapping 300, DMRSs 306 and 328 are mapped to symbols 302 in time and subcarriers 304 in frequency. In this example, the DMRSs 308, 312, 316, 320, 324, and 328 for WTRU1 and the DMRSs 306, 310, 314, 318, 322, and 326 for WTRU2 alternate on each subcarrier of the third symbol. The DMRSs 306, 310, 314, 318, 322, and 326 are transmitted by the WTRU 2. The DMRSs 308, 312, 316, 320, 324, and 328 are transmitted by the WTRU 1.

In the example mapping 330, DMRS is also mapped to symbols 332 in time and subcarriers 334 in frequency. In this example, the DMRS for WTRU1 and WTRU2 alternates on each subcarrier of the third symbol and the fourth symbol. DMRSs 336, 338, 344, 346, 352, 354, 360, 362, 368, 370, 376, and 378 are transmitted by WTRU 2. DMRSs 330, 342, 348, 350, 356, 358, 364, 366, 372, 374, 380, and 382 are transmitted by WTRU 1.

In some implementations, the sequence of the DMRS is determined in the frequency domain using Quadrature Phase Shift Keying (QPSK) modulation. For example, table 1 defines a sequence of a DMRS of length 6 (i.e., sequence length 6), whereIs a modulation operation of a sequence index u, where phi_u(n) is the nth element of the nth sequence.

TABLE 1

In one embodiment, the modulation sequences are mapped directly to subcarriers. It should be noted that the PAPR/CM performance of these sequences is not optimized for DFT-spread OFDM data channels and may result in a higher PAPR than the PAPR of data spread OFDM with pi/2-BPSK DFT.

Fig. 4 is a block diagram illustrating an example transmitter 400 of a DMRS compatible with the type 1 mapping illustrated in fig. 3. In this example, a sequence may be determined from the set of sequences 402 based on the sequence index u 404 and the selected sequence may be modulated 406 with the modulation type in the modulation box. To implement type 1 mapping, the resulting output is repeated twice and with w₁408 and w₂410 multiplication of w₁＝w₂For in one WTRU, w₁＝-w₂For another WTRU. The sequence is then processed by the blocks in DFT-s-OFDM 412 along with FDSS 414, IDFT 416 is computed, and the resulting vector may be transmitted.

In some examples, to achieve good performance in a cellular network, the set of sequences in fig. 4 may result in signals with low PAPR, low CM, low cross-correlation with other DMRS signals, large zero autocorrelation regions for estimating the channel, and high frequency flatness for achieving better BLER performance and compatible with spectral requirements. Several example sequences are provided herein.

Table 2 shows an example set of sequences that may be defined for length 6, 8-PSK modulation, DFT-s-OFDM for type 1 mapping.

TABLE 2

In this example, the modulation symbols are generated using:

table 3 shows an example set of sequences that may be defined for length 12, where pi/2-BPSK modulation is used for DFT-s-OFDM for type 1 mapping.

TABLE 3

In this example, the modulation symbols are generated using the following equation:

table 4 shows an example set of sequences that may be defined for length 18, where pi/2-BPSK modulation is used for DFT-s-OFDM for type 1 mapping.

TABLE 4

In this example, the modulation symbols are generated using the following equation:

table 5 shows an example set of sequences that may be defined for length 24, where pi/2-BPSK modulation is used for DFT-s-OFDM for type 1 mapping.

TABLE 5

The modulation symbols are generated using the following equation:

in some implementations, for example, to achieve good performance of DMRS for pi/2BPSK DFT-spread OFDM with FDSS in a cellular network, the sequence set is configured to minimize one or more (or all) of the following metrics: measure 1[ dB ]: PAPR with FDSS; measure 2 [ dB ]: a CM with FDSS; measurement 3: cyclic autocorrelation over time (measuring frequency fluctuations) of all lags; measurement 4: cyclic autocorrelation over time for the 1, 1 lag (measure whether there is a zero autocorrelation region for the channel estimation quality at the 1, 1 lag); measurement 5: cyclic autocorrelation over time for the { -2, -1, 1, 2} lag (measure whether there is a zero autocorrelation region for the channel estimation quality at the { -2, -1, 1, 2} lag); measurement 6: for cyclic autocorrelation over time of the { -3, -2, -1, 1, 2, 3} lag (measure whether there is a zero autocorrelation region for channel estimation quality at the { -3, -2, -1, 1, 2, 3} lag); and 7, measurement: maximum peak cross-correlation with another DMRS signal (measurement of inter-cell interference).

Example distributions of metrics for the sequence sets given in tables 2, 3,4 and 5 are shown by considering an example FDSS with a filter of [0.28, 1, 0.28 ]. Table 6 shows the maximum values of the metrics corresponding to these examples.

TABLE 6

In some implementations, the above-described set of sequences may perform well in terms of PAPR and CM; however, in some implementations they may not provide good results in terms of frequency flatness, cross-correlation (inter-cell interference), and/or cyclic autocorrelation (channel estimation performance). Thus, in some embodiments, a new set of sequences for different lengths is provided.

In some implementations, the type 1 mapping may also vary from or may otherwise differ from the structure given in fig. 4. For example, different w may be varied₁And w₂Properties of the sequence of the codebook. In some implementations, different Orthogonal Cover Codes (OCCs) may be provided, e.g., w₁And w₂. In some implementations, w₁And w₂Each element of the sequence may be changed differently.

Some implementations include replacement-based collections. For example, an existing sequence may be changed by replacing N sequences in an existing set (e.g., the set described above with respect to tables 2, 3,4, and 5). For example, for length 6, N ═ {3, 4.. 13,16} substitutions may be made in table 2 with the sequence given in table 11, e.g., to improve the performance of DMRS for pi/2-BPDFT-s-OFDM with type 1 mapping. Table 7 shows an example performance improvement for a given N in this case. For length 12, N ═ {3,4,. 13,14} substitutions may be made in table 3 with the sequence given in table 12, for example, to improve the performance of DMRS for pi/2-BPSK DFT-s-OFDM with type 1 mapping. Table 8 shows example performance improvements for a given N in this case. For length 18, N ═ {3,4,. 13,18} substitutions may be made in table 4 with the sequence given in table 13, for example, to improve the performance of DMRS for pi/2-BPSK DFT-s-OFDM with type 1 mapping. Table 9 shows example performance improvements for a given N in this case. For length 18, N ═ {3,4,. 13,18} substitutions can be made in table 5 with the sequence given in table 14, for example, to improve the performance of DMRS for pi/2-BPSK DFT-s-OFDM with type 1 mapping. Table 10 shows example performance improvements for a given N in this case.

In some implementations, the indexes of the final sequence in the set may be reordered, for example, using reordering by rows. In some implementations, the order of the elements of the sequence may be reversed. In some implementations, the modulated sequence may be inverted and/or conjugated. In some implementations, these operations do not change the properties of the set of sequences.

TABLE 7

Length 6 performance of replacement-based collections

TABLE 8

Length 12 performance based on alternative sets

TABLE 9

Length 18 performance based on replacement set

Watch 10

Length 24 performance based on alternate sets

Table 11 shows a new sequence based on the set of alternatives with length 6 (modulation: 8-PSK).

TABLE 11

In some implementations, for example, if the sequence length is 6, at least one of the values provided in table 11a may be used as the value of the phase parameter Φ (n):

TABLE 11a

Thereafter, the inverted version of the length-N sequence may be considered to be the same sequence. For example, the sequences φ (0), …, φ (N-1) and their inverted versions φ (N-1), …, φ (0) may be considered to be identical sequences.

Table 12 shows a new sequence based on a set of alternatives of length 12 (modulation: pi/2-BPSK).

TABLE 12

In some implementations, for example, if the sequence length is 12, at least one of the values provided in table 12a may be used as the phase parameter φ_uThe value of (n):

TABLE 12a

Table 13 shows a new sequence based on a set of alternatives of length 18 (modulation: π/2-BPSK).

Watch 13

In some implementations, for example, if the sequence length is 18, at least one of the values provided in table 13a may be used as the phase parameter φ_uThe value of (n):

TABLE 13a

Table 14 shows a new sequence based on a set of alternatives of length 24 (modulation: pi/2-BPSK).

TABLE 14

In some implementations, for example, if the sequence length is 24, at least one of the values provided in table 14a may be used as the phase parameter φ_uThe value of (n):

TABLE 14a

Some implementations include a new set of sequences. Tables 16, 17, 18, 19, 20, 21, 22, 23, and 24 may be used as DMRS sequences for QPSK of length 6, 8-PSK of length 6, 12-PSK of length 6, pi/2-BPSK of length 12, pi/2-BPSK of length 18, and pi/2-BPSK of length 24, respectively.

In some examples, at least one of the values provided in the following table may be used as a phase parameterThe value of (c). In some examples, a phase modulated or rotated version of the corresponding sequence in frequency may be utilized. The sequence set may be used for type 1 mapping together with OCC or frequency shift based user multiplexing methods, e.g. as given in fig. 4 and 5.

Table 15 shows example performance of an example new sequence set.

Watch 15

In some implementations, the indexes of the final sequence in the set may be reordered, e.g., based on reordering by rows. In some embodiments, the order of the elements of the sequence may be reversed. In some embodiments, the modulated sequence may be inverted and/or conjugated. In some implementations, these operations do not change the properties of the set of sequences.

In some examples, for a sequence length of 6 with π/2-BPSK modulation whose autocorrelation is prioritized (e.g., where the sequence has very good autocorrelation; is above a threshold cross-correlation and has acceptable cross-correlation properties; and/or is above a threshold cross-correlation), at least one of the values provided in the following table is used as a phase parameterThe value of (c):

TABLE 16

The modulation symbols are generated using:

in some examples, if the sequence length is 6 (modulation: π/2-BPSK-cross-correlation first-i.e., cross-correlation is prioritized; e.g., where the sequences have very good cross-correlation (e.g., above a threshold cross-correlation) andhaving acceptable autocorrelation properties (e.g., above a threshold autocorrelation)), at least one of the values provided in the following table is used as a phase parameterThe value of (c):

TABLE 17

The modulation symbols are generated using:

in some examples, for a sequence length of 6 using QPSK modulation in which the autocorrelation is prioritized (e.g., where the sequence has very good autocorrelation above a threshold cross-correlation and has acceptable cross-correlation properties (e.g., above the threshold cross-correlation)), at least one of the values provided in the following table is used as the phase parameterThe value of (c):

watch 18

The modulation symbols are generated using:

in some examples, for a sequence length of 6 with QPSK modulation (where the cross-correlation is prioritized; e.g., where the sequence has very good cross-correlation above a threshold cross-correlation and has acceptable auto-correlation properties (e.g., above a threshold auto-correlation)), at least one of the values provided in the table below is used as the phase parameterThe value of (c):

watch 19

The modulation symbols are generated using:

in some examples, for a sequence length of 6 (modulation: 8-PSK), at least one of the values provided in table 20 is used as the value of the phase parameter phi (n):

watch 20

In this example, the modulation symbols are generated using:

in some examples, for a sequence length of 6 (modulation: 12-PSK), at least one of the values provided in Table 21 is used as the phase parameter φ_uThe value of (n):

TABLE 21

In some examples, if the sequence length is 12 (modulation: π/2-BPSK), at least one of the values provided in Table 22 is used as the phase parameter φ_uThe value of (n):

TABLE 22

In this example, the modulation symbols are generated using the following equation:

in some examples, one or more sequences from the set of sequences including sequence indices 9, 10, 19, and 11 in table 22 may be used specifically as DMRSs and combined with other sequences.

In some examples, one or more sequences from the set of sequences comprising sequence indices 9, 10, 19, 11, 27, 28, 4, 5 in table 22 may be used specifically as DMRSs, and may be combined with other sequences.

In some casesIn the example, if the sequence length is 18 (modulation: π/2-BPSK), at least one of the values provided in Table 23 is used as the phase parameter φ_uThe value of (n):

TABLE 23

In this example, the modulation symbols are generated using the following equation:

in some examples, one or more sequences from the set of sequences including sequence indices 18, 22, 3,8, 14, 2, 7, and 29 in table 23 may be used specifically as DMRSs and combined with other sequences.

In some examples, one or more sequences from the set of sequences including sequence indices 18, 22, 3, and 8 in table 23 may be used specifically as DMRSs and combined with other sequences.

In some examples, if the sequence length is 24 (modulation: pi/2-BPSK), at least one of the values provided in table 24 is used as the phase parameter φ_uThe value of (n):

watch 24

In this example, the modulation symbols are generated using the following equation:

in some examples, one or more sequences from the set of sequences including sequence indices 29, 6, 27, 28, 23, 11, 22, and 12 in table 24 may be used specifically as DMRSs, and may be combined with other sequences.

In some examples, one or more sequences from the set of sequences including sequence indices 29, 6, 27, and 28 in table 24 may be used specifically as DMRSs and combined with other sequences.

Some implementations include user multiplexing.

Fig. 5 is a block diagram illustrating an example of user multiplexing, including an example transmitter 500 for generating DMRS signals without losing properties of a set of sequences. In this example, in a first block, a sequence may be determined from the set of sequences 502 based on the sequence index u 504. In a second block, the selected sequence may be modulated 506 with a modulation type (e.g., pi/2-BPSK). The resulting output may be repeated 508, 510 twice. Thereafter, the repeated sequence may be precoded by the DFT precoder 512 in the third block, and the output of the DFT may be shifted 514 in the fourth block by the WTRU index 516, the OCC index, or other index to enable type 1 mapping. The sequence is then processed with FDSS 518 in a fifth block. In a sixth block, an IDFT 520 is computed and the result vector may be sent. In some embodiments, the method does not change the properties of the set of sequences; such as cross-correlation properties, PAPR, CM and/or auto-correlation properties. In some examples, the sequences may be cyclically shifted to enable multiple orthogonal DMRS ports prior to the DFT operation. In some examples, phase rotation or modulation operations, i.e.,where n, k ∈ {0,1, …, M-1}, s may be a repeated sequence or a repeated sequence prior to an IDFT operation. In some examples, the same operations may be used to shift the sequence in frequency.

Although features and elements are described above in particular combinations, one of ordinary skill in the art will recognize that each feature or element can be used alone or in any combination with other features and elements. Furthermore, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer readable media include electronic signals (transmitted over wired or wireless connections) and computer readable storage media. Examples of computer readable storage media include, but are not limited to, Read Only Memory (ROM), Random Access Memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (e.g., internal hard disks and removable disks), magneto-optical media, and optical media (e.g., CD-ROM disks and Digital Versatile Disks (DVDs)). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any computer host.