阅读说明：本技术 基于多层正交调制的多载波发送方法及接收方法 (Multi-carrier sending method and receiving method based on multi-layer orthogonal modulation ) 是由 陈晓华 王祥 于 2021-08-25 设计创作，主要内容包括：基于多层正交调制的多载波发送方法及接收方法,解决了现有多载波传输硬件复杂度高的问题,属于通信领域。本发明发送多载波时,在发送端,对2M路信号s-(p)(t)进行log-(2)2M层正交调制,获得一路信号发送给接收端,log-(2)2M层的调制频率分别为f-(1)至及f-(c),其中利用振荡器产生一个频率载波,在该频率载波基础上共产生log-(2)(2M)-1个不同频率的载波,且log-(2)(2M)-1个频率依次按a倍递增,f-(1)至为log-(2)(2M)-1个频率任意顺序组合,f-(c)表示射频载波的频率,a≥2。在接收端,接收信号进行log-(2)2M层正交解调,第一层使用频率f-(c)进行正交解调,第2层至第log-(2)2M层解调时分别使用频率至f-(1)进行正交解调,与发送端调制时的调制频率相同。(A multi-carrier sending method and a multi-carrier receiving method based on multi-layer orthogonal modulation solve the problem of high complexity of the existing multi-carrier transmission hardware, and belong to the field of communication. When the invention sends multiple carriers, at the sending end, 2M paths of signals s are processed p (t) log of 2 2M layer quadrature modulation, obtaining one path signal and sending to receiving end, log 2 The modulation frequencies of the 2M layers are respectively f 1 To And f c Wherein an oscillator is used to generate a frequency carrier on the basis of which a log is co-generated 2 (2M) -1 carriers of different frequencies, and log 2 (2M) -1 frequency is increased by a times in sequence, f 1 To Is log 2 (2M) -1 frequencies combined in an arbitrary order, f c Representing the frequency of a radio frequency carrier, aNot less than 2. At the receiving end, the received signal is log 2 2M layers of quadrature demodulation, the first layer using a frequency f c Performing quadrature demodulation, layer 2 to log 2 Frequency is used in 2M layer demodulation To f 1 Quadrature demodulation is performed at the same modulation frequency as that at the time of modulation at the transmitting end.)

1. The multi-carrier transmission method based on the multi-layer orthogonal modulation is characterized by comprising the following steps:

s1 sending end bit stream b^TD is obtained through constellation mapping^TThen, after serial-to-parallel conversion, M parallel signals d are generated_mParallel signal d_mPerforming pre-transformation on W to obtain M paths of complex signals x_m，m＝1，…，M；

S2, converting the complex signal x_mThe real part and the imaginary part are separated to obtain a 2M real signal s_p，p＝1，…，2M；

S3, 2M real signal S_pObtaining a continuous time signal s through pulse shaping_p(t)；

S4, for 2M path signal S_p(t) log of₂2M layer quadrature modulation, wherein the 1 st layer modulation object is 2M path signal s_p(t) modulation object of each layer thereafterIs the modulation output of the previous layer; modulation process of k layer for odd channel data utilizationTo modulate, even-term channel data utilizationModulating, adding the data modulated by the odd-numbered channel and the adjacent next even-numbered channel to be one channel data of the modulation output of the layer, wherein k is 1, …, log₂(2M) -1; the modulation process of the last layer is to respectively utilize the data of two channelsAndmodulating, adding the modulated data to obtain a signalWill signalSending;

f₁toAnd f_cFor modulating the frequency, the method for acquiring the modulation frequency comprises the following steps:

using an oscillator to generate a frequency carrier on the basis of which log is co-generated using a frequency divider and/or a frequency multiplier₂(2M) -1 carriers of different frequencies, and log₂(2M) -1 frequency is increased by a times in sequence, f₁ToIs log₂(2M) -1 frequencies combined in an arbitrary order, f_cIndicating beamThe frequency of the frequency carrier, a, is greater than or equal to 2.

2. The multi-layered orthogonal modulation based multi-carrier transmission method as claimed in claim 1, wherein f₁Not less than B/2, the bandwidth of each signal is B, f_α≥2f_α-1，α＝2，…，log₂(2M)-1，f_cAccording to the actually required radio frequency.

3. The multi-layered orthogonal modulation based multi-carrier transmission method as claimed in claim 2, wherein log is generated₂The (2M) -1 method of carrier waves of different frequencies comprises the following steps:

utilizing a low-frequency oscillator to generate a 1 st frequency carrier, generating a 2 nd frequency carrier by the 1 st frequency carrier through a frequency multiplier, inputting the 2 nd frequency carrier into a second frequency multiplier to generate a 3 rd frequency carrier, and so on until a log is generated₂(2M) -1 frequency carrier;

using a radio-frequency oscillator to generate a frequency f_cThe radio frequency carrier of (1).

4. The multi-layer orthogonal modulation based multi-carrier transmission method according to claim 1,

generating the 1 st frequency carrier by using a high-frequency oscillator, generating the 2 nd frequency carrier by the 1 st frequency carrier through a frequency divider, inputting the 2 nd frequency carrier into a second frequency divider to generate the 3 rd frequency carrier, and so on until the log is generated₂(2M) -1 frequency carrier;

using a radio-frequency oscillator to generate a frequency f_cThe radio frequency carrier of (1).

5. The multi-carrier transmission method based on multi-layer orthogonal modulation as claimed in claim 1, wherein an intermediate frequency oscillator is used to generate a 1 st frequency carrier, the 1 st frequency carrier generates a 2 nd frequency carrier through a frequency divider, the 2 nd frequency carrier is input to a second frequency divider to generate a 3 rd frequency carrier, and so on until a b th frequency carrier is generated;

the first frequency carrier generates the (b + 1) th frequency carrier through a frequency multiplier, the (b + 1) th frequency carrier is input into a second frequency multiplier to generate the (b + 2) th frequency carrier, and so on until the log is generated₂(2M) -1 frequency carrier;

using a radio-frequency oscillator to generate a frequency f_cThe radio frequency carrier of (1).

6. The multi-layered orthogonal modulation based multi-carrier transmission method as claimed in claim 1, wherein the parallel signal d is_mPerforming pre-transformation to obtain M paths of complex signals x_mThe method comprises the following steps:

x＝Wd＝[x₁，…，x_M]^T

w represents a pre-transformation matrix;

when M is 2ⁿWhen W is equal to W_nIs provided with

And is

7. The multi-carrier receiving method based on the multi-layer orthogonal modulation is characterized by comprising the following steps:

s5, receiving end receives signalSignalLog of₂2M layer quadrature demodulation in which the demodulation object of layer 1 is a signalThen the demodulation object of each layer is the demodulation output of the previous layer; first layer use frequency f_cPerforming quadrature demodulation to obtain two paths of outputs; layer 2 to log₂Frequency is used in 2M layer demodulationTo f₁Performing quadrature demodulation to obtain 2M path signals

f₁ToAnd f_cIn order to demodulate the frequency, and the frequency is the same as the frequency when the sending end modulates, the method for obtaining the demodulation frequency is as follows:

using an oscillator to generate a frequency carrier on the basis of which f is co-generated using a frequency divider and/or a frequency multiplier₁ToA carrier wave of frequency;

s6, 2M path signalObtaining a baseband continuous time signal r through a pulse forming matched filter_p(t) base band continuous time signal r_p(t) sampling to obtain a digital real signal r ═ r₁，r₂，…，r_2M]^T；

S7, 2M digital real signals are grouped into M digital complex signals z_mIs subjected to transformation W^HObtaining M paths of signals u_m，m＝1，…，M，u＝[u₁，u₂，…，u_M]^T，u＝W^Hz，z＝[z₁，z₂，…，z_M]^T，W^HDenotes the conjugate transpose of W, W denotes transmissionPre-transformation matrix when the end is transformed into complex signal before modulation;

s8, M path signal u_mRespectively carrying out single-tap equalization to obtain M paths of signals y_m，y＝[y₁，y₂，…，y_M]^TM paths of signal y_mObtaining a bit stream estimated value b through parallel-to-serial conversion and constellation demapping in sequence^T。

8. A multi-carrier transmission apparatus based on multi-layer orthogonal modulation, comprising:

a constellation mapping module connected with the serial-to-parallel conversion module for mapping the bit stream b^TPerforming constellation mapping to obtain a signal d^TSending the data to a serial-parallel conversion module;

a serial-to-parallel conversion module connected with the multi-layer IQ modulation module for converting the signal d^TPerforming serial-to-parallel conversion to generate M parallel signals d_mParallel signal d_mSending the data to a multi-layer IQ modulation module;

a frequency generation module connected with the multi-layer IQ modulation module and used for generating a frequency carrier by using the oscillator and co-generating log by using the frequency divider and/or the frequency multiplier on the basis of the frequency carrier₂(2M) -1 carriers of different frequencies, and log₂Increasing the (2M) -1 frequency by a times in sequence, and dividing log₂(2M) -1 frequencies are combined in an arbitrary order as a modulation frequency f₁Toa is more than or equal to 2, and the frequency generated by the radio frequency oscillator is f_cRadio frequency carrier of, will f₁ToAnd f_cSending the data to a multi-layer IQ modulation module;

a multi-layer IQ modulation module connected with the transmitting antenna and used for the M paths of parallel signals d_mPerforming pre-transformation on W to obtain M paths of complex signals x_mM is 1, …, M; 2M real signal s_pObtaining a continuous time signal s through pulse shaping_p(t)；For 2M signals s_p(t) log of₂2M layer quadrature modulation, wherein the 1 st layer modulation object is 2M path signal s_p(t), the modulation object of each layer thereafter being the modulation output of the previous layer; modulation process of k layer for odd channel data utilizationTo modulate, even-term channel data utilizationModulating, and adding the data modulated by the odd-numbered channel and the adjacent next even-numbered channel to be used as channel data of the layer modulation output; k is 1, …, log₂(2M) -1; the modulation process of the last layer is to respectively utilize the data of two channelsAndmodulating, adding the modulated data to obtain a signalAnd sending to a sending antenna;

transmitting antenna for transmitting signalAnd (5) sending.

9. A multi-layer orthogonal modulation based multi-carrier receiving apparatus, comprising:

a receiving antenna connected with the multi-layer IQ demodulation module for receiving signals at the receiving endAnd sending to a multi-layer IQ demodulation module;

frequency generating modeA block connected with the multi-layer IQ demodulation module for generating a frequency carrier by using the oscillator, and co-generating f by using the frequency divider and/or the frequency multiplier based on the frequency carrier₁ToA carrier wave of frequency; using a radio frequency oscillator to generate a frequency f_cRadio frequency carrier of, will f₁ToAnd f_cSending the data to a multilayer IQ demodulation module; f. of₁ToAnd f_cThe frequency is a demodulation frequency and is the same as the frequency when the sending end modulates;

multi-layered IQ demodulation module, connected to single-tap equalizer, for receiving signalsLog of₂2M layer quadrature demodulation in which the demodulation object of layer 1 is a signalThen the demodulation object of each layer is the demodulation output of the previous layer; first layer use frequency f_cPerforming quadrature demodulation to obtain two paths of outputs; layer 2 to log₂Frequency is used in 2M layer demodulationTo f₁Performing quadrature demodulation to obtain 2M path signals2M path signalPulse shaping matched filteringA device for obtaining a base band continuous time signal r_p(t) base band continuous time signal r_p(t) sampling to obtain a digital real signal r ═ r₁，r₂，…，r_2M]^T(ii) a The 2M digital real signals are grouped into M digital complex signals z_mIs subjected to transformation W^HObtaining M paths of signals u_m，u＝[u₁，u₂，…，u_M]^T，u＝W^Hz，z＝[z₁，z₂，…，z_M]^T，W^HDenotes the conjugate transpose of W, W denotes the pre-transform matrix when transforming to complex signal before modulation at the transmitting end, and M paths of signals u_mSending to a single tap equalizer; m is 1, …, M;

a single-tap equalizer connected with the serial-to-parallel conversion module for dividing the M signals u_mRespectively carrying out single-tap equalization to obtain M paths of signals y_m，y＝[y₁，y₂，…，y_M]^TAnd will combine the M signals y_mSending the data to a serial-parallel conversion module;

a serial-parallel conversion module connected with the constellation demapping module and used for converting the M paths of signals y_mThrough parallel-to-serial conversion, a path of serial signal y is obtained^TAnd sending the data to a constellation demapping module; f. of₁ToFor any sequential combination of successively increasing doubling frequencies, f_cRepresenting a frequency of a radio frequency carrier; f. of₁ToAnd f_cThe same frequency as that of the transmitting device when modulated;

a constellation demapping module for demapping the serial signal y^TPerforming constellation demapping to obtain bit stream estimated value b^T。

Technical Field

The invention relates to a method for realizing multi-load sending and receiving, belonging to the field of communication.

Background

Orthogonal Frequency Division Multiplexing (OFDM) has played a very important role in the past, such as 4G and WiFi. And it is still used in 5G NR. In OFDM, a high-speed serial data stream is converted into several lower-speed data streams, and the receiving end only needs to perform simple equalization to recover the data. But its simplicity is mainly due to the elimination of inter-carrier interference and inter-symbol interference when the Cyclic Prefix (CP) is larger than the channel delay spread. However, the transmission of the CP needs to consume additional bandwidth, resulting in reduced spectral efficiency. For example, in 5GNR, the length of the CP is 19.5% of the OFDM symbol in some cases. Therefore, the CP will become a bottleneck for further improving the spectrum efficiency of future communication. Furthermore, large bandwidth is the direction of communication development. Under the OFDM scheme, a larger bandwidth tends to mean more subcarriers. This will make the peak-to-average ratio (PAPR) problem more severe.

In fact, multi-carrier modulation is not just OFDM. The earliest multi-carriers came from the conventional FDM technique, using filters to separate the individual sub-bands, each of which required the use of a bandwidth of (1+ epsilon) f_sThis exceeds the Nyquist minimum f_sTherefore, the spectral efficiency is 1/(1+ epsilon), and a very narrow transition band filter design is required to achieve a relatively high spectral efficiency. In the past, some systems have used this approach, such as Kinematic, kanthron, and the like. Later researchers discovered that certain sub-bands could be allowed to overlap to improve spectral efficiency, and each sub-band still required bandwidth of (1+ epsilon) f_sThe subbands overlap at-3 dB frequencies, with the net effect that the superimposed spectrum is flat. If ε < 1, each subband overlaps only adjacent subbands, orthogonality between subbands is achieved by the filter bank, and therefore the number of filters required is large. Meanwhile, the scholars separate the carriers by using the Sinc function, and different from the former, each carrier is not band-limited, the separated subcarriers do not use band-pass filters but use baseband processing, and the receiving end and the transmitting end can be realized by using the FFT technology, so that the scholars can also separate the carriers by using the Sinc functionIs known as OFDM.

OFDM has experienced explosive growth since the last 70 s researchers proposed OFDM. However, until now, it still faces a number of problems that are difficult to solve, such as CP consuming extra bandwidth without efficiently transmitting information, high PAPR, high out-of-band leakage, etc. But these problems are not present in radio frequency multi-carrier transmission. However, this multi-carrier mode requires a large number of rf oscillators and is extremely complex when the number of carriers is large. It is in fact necessary to reduce the power consumption of the device as much as possible while meeting the requirements for reliable transmission. Highly integrated designs can reduce cost and power consumption by employing standard silicon fabrication processes, such as CMOS. With the progress of semiconductor technology, the rf performance of silicon-based CMOS processes for digital integrated circuits is gradually increasing. This provides the basis for the multi-carrier development to recover the radio frequency from baseband. It is too complicated to implement multiple carriers directly using multiple oscillators, especially when the number of carriers is large.

Disclosure of Invention

Aiming at the problem of high complexity of the existing multi-carrier transmission hardware, the invention provides a multi-carrier transmission method and a multi-carrier receiving method based on multi-layer orthogonal modulation.

The invention relates to a multi-carrier sending method based on multilayer orthogonal modulation, which comprises the following steps:

s1 sending end bit stream b^TD is obtained through constellation mapping^TThen, after serial-to-parallel conversion, M parallel signals d are generated_mParallel signal d_mPerforming pre-transformation on W to obtain M paths of complex signals x_m，m＝1，…，M；

S2, converting the complex signal x_mThe real part and the imaginary part are separated to obtain a 2M real signal s_p，p＝1，…，2M；

S3, 2M real signal S_pObtaining a continuous time signal s through pulse shaping_p(t)；

S4, for 2M path signal S_p(t) log of₂2M layer quadrature modulation, wherein the first layer modulation object is 2M path signal s_p(t), thereafter adjusting each layerThe object is the modulation output of the previous layer; modulation process of k layer for odd channel data utilizationTo modulate, even-term channel data utilizationModulating, adding the data modulated by the odd-numbered channel and the adjacent next even-numbered channel to be one channel data of the modulation output of the layer, wherein k is 1, …, log₂(2M) -1; the modulation process of the last layer is to respectively utilize the data of two channelsAndmodulating, adding the modulated data to obtain a signalWill signalSending;

f₁toAnd f_cFor modulating the frequency, the method for acquiring the modulation frequency comprises the following steps:

generating a frequency carrier by means of an oscillator, co-generating log on the basis of the frequency carrier₂(2M) -1 carriers of different frequencies, and log₂(2M) -1 frequency is increased by a times in sequence, f₁ToIs log₂(2M) -1 frequencies combined in an arbitrary order, f_cRepresents the frequency of the radio frequency carrier wave, and a is more than or equal to 2.

Preferably, f₁Not less than B/2, bandwidth of each path of signalIs B, f_α≥2f_α-1，α＝2，…，log₂(2M)-1，f_cAccording to the actually required radio frequency.

Preferably, log is generated₂The (2M) -1 method of carrier waves of different frequencies comprises the following steps:

utilizing a low-frequency oscillator to generate a 1 st frequency carrier, generating a 2 nd frequency carrier by the 1 st frequency carrier through a frequency multiplier, inputting the 2 nd frequency carrier into a second frequency multiplier to generate a 3 rd frequency carrier, and so on until a log is generated₂(2M) -1 frequency carrier;

using a radio-frequency oscillator to generate a frequency f_cThe radio frequency carrier of (1).

Preferably, a high frequency oscillator is used to generate the 1 st frequency carrier, the 1 st frequency carrier is used to generate the 2 nd frequency carrier through a frequency divider, the 2 nd frequency carrier is input to a second frequency divider to generate the 3 rd frequency carrier, and so on until the log is generated₂(2M) -1 frequency carrier;

using a radio-frequency oscillator to generate a frequency f_cThe radio frequency carrier of (1).

Preferably, an intermediate frequency oscillator is used for generating a 1 st frequency carrier, the 1 st frequency carrier generates a 2 nd frequency carrier through a frequency divider, the 2 nd frequency carrier is input into a second frequency divider to generate a 3 rd frequency carrier, and the like until a b-th frequency carrier is generated;

the first frequency carrier generates the (b + 1) th frequency carrier through a frequency multiplier, the (b + 1) th frequency carrier is input into a second frequency multiplier to generate the (b + 2) th frequency carrier, and so on until the log is generated₂(2M) -1 frequency carrier;

using a radio-frequency oscillator to generate a frequency f_cThe radio frequency carrier of (1).

Preferably, the parallel signal d_mPerforming pre-transformation to obtain M paths of complex signals x_mThe method comprises the following steps:

x＝Wd＝[x₁，…，x_M]^T

w represents a pre-transformation matrix;

when M is 2ⁿWhen W is equal to W_nIs provided with

And is

The invention also provides a multi-carrier receiving method based on multilayer orthogonal modulation, which comprises the following steps:

s5, receiving end receives signalSignalLog of₂2M layer quadrature demodulation in which the demodulation object of layer 1 is a signalThen the demodulation object of each layer is the demodulation output of the previous layer; first layer use frequency f_cPerforming quadrature demodulation to obtain two paths of outputs; layer 2 to log₂Frequency is used in 2M layer demodulationTo f₁Performing quadrature demodulation to obtain 2M path signalsp＝1，…，2M；

f₁ToAnd f_cIn order to demodulate the frequency, and the frequency is the same as the frequency when the sending end modulates, the method for obtaining the demodulation frequency is as follows:

using oscillationsThe device generates a frequency carrier on the basis of which f is co-generated₁ToA carrier wave of frequency;

s6, 2M path signalObtaining a baseband continuous time signal r through a pulse forming matched filter_p(t) base band continuous time signal r_p(t) sampling to obtain a digital real signal r ═ r₁，r₂，…，r_2M]^T；

S7, 2M digital real signals are grouped into M digital complex signals z_mIs subjected to transformation W^HObtaining M paths of signals u_m，m＝1，…，M，u＝[u₁，u₂，…，u_M]^T，u＝W^H，z＝[z₁，z₂，…，z_M]^T，W^HRepresenting the conjugate transpose of W, wherein W represents a pre-transformation matrix when a transmitting end is transformed into a complex signal before modulation;

s8, M path signal u_mRespectively carrying out single-tap equalization to obtain M paths of signals y_m，y＝[y₁，y₂，…，y_M]^TM paths of signal y_mObtaining a bit stream estimated value b through parallel-to-serial conversion and constellation demapping in sequence^T。

The invention also provides a multi-carrier transmitting device based on multi-layer orthogonal modulation, which comprises:

a constellation mapping module connected with the serial-to-parallel conversion module for mapping the bit stream b^TPerforming constellation mapping to obtain a signal d^TSending the data to a serial-parallel conversion module;

a serial-to-parallel conversion module connected with the multi-layer IQ modulation module for converting the signal d^TPerforming serial-to-parallel conversion to generate M parallel signals d_mParallel signal d_mSending the data to a multi-layer IQ modulation module;

a frequency generation module connected with the multi-layer IQ modulation module for generating a frequencyGenerating a frequency carrier by means of an oscillator, co-generating log on the basis of the frequency carrier₂(2M) -1 carriers of different frequencies, and log₂Increasing the (2M) -1 frequency by a times in sequence, and dividing log₂(2M) -1 frequencies are combined in an arbitrary order as a modulation frequency f₁Toa is more than or equal to 2, and the frequency generated by the radio frequency oscillator is f_cRadio frequency carrier of, will f₁ToAnd f_cSending the data to a multi-layer IQ modulation module;

a multi-layer IQ modulation module connected with the transmitting antenna and used for the M paths of parallel signals d_mPerforming pre-transformation on W to obtain M paths of complex signals x_mM is 1, …, M; 2M real signal s_pObtaining a continuous time signal s through pulse shaping_p(t); for 2M signals s_p(t) log of₂2M layer quadrature modulation, wherein the 1 st layer modulation object is 2M path signal s_p(t), the modulation object of each layer thereafter being the modulation output of the previous layer; modulation process of k layer for odd channel data utilizationTo modulate, even-term channel data utilizationModulating, and adding the data modulated by the odd-numbered channel and the adjacent next even-numbered channel to be used as channel data of the layer modulation output; k is 1, …, log₂(2M) -1; the modulation process of the last layer is to respectively utilize the data of two channelsAndto modulate, to add modulated dataThen obtaining the signalAnd sending to a sending antenna;

transmitting antenna for transmitting signalAnd (5) sending.

The invention also provides a multi-carrier receiving device based on multi-layer orthogonal modulation, which comprises:

a receiving antenna connected with the multi-layer IQ demodulation module for receiving signals at the receiving endAnd sending to a multi-layer IQ demodulation module;

a frequency generation module connected with the multi-layer IQ demodulation module and used for generating a frequency carrier by using the oscillator and generating f together on the basis of the frequency carrier₁ToA carrier wave of frequency; using a radio frequency oscillator to generate a frequency f_cRadio frequency carrier of, will f₁ToAnd f_cSending the data to a multilayer IQ demodulation module; f. of₁ToAnd f_cThe frequency is a demodulation frequency and is the same as the frequency when the sending end modulates;

multi-layered IQ demodulation module, connected to single-tap equalizer, for receiving signalsLog of₂2M layer quadrature demodulation in which the demodulation object of layer 1 is a signalThen the demodulation object of each layer is the demodulation output of the previous layer; first layer use frequency f_cPerforming quadrature demodulation to obtain two paths of outputs; layer 2 to log₂Frequency is used in 2M layer demodulationTo f₁Performing quadrature demodulation to obtain 2M path signalsp ═ 1, …, 2M; 2M path signalObtaining a baseband continuous time signal r through a pulse forming matched filter_p(t) base band continuous time signal r_p(t) sampling to obtain a digital real signal r ═ r₁，r₂，…，r_2M]^T(ii) a The 2M digital real signals are grouped into M digital complex signals z_mIs subjected to transformation W^HObtaining M paths of signals u_m，u＝[u₁，u₂，…，u_M]^T，u＝W^Hz，z＝[z₁，z₂，…，z_M]^T，W^HDenotes the conjugate transpose of W, W denotes the pre-transform matrix when transforming to complex signal before modulation at the transmitting end, and M paths of signals u_mSending to a single tap equalizer; m is 1, …, M;

a single-tap equalizer connected with the serial-to-parallel conversion module for dividing the M signals u_mRespectively carrying out single-tap equalization to obtain M paths of signals y_m，y＝[y₁，y₂，…，y_M]^TAnd will combine the M signals y_mSending the data to a serial-parallel conversion module;

a serial-parallel conversion module connected with the constellation demapping module and used for converting the M paths of signals y_mThrough parallel-to-serial conversion, a path of serial signal y is obtained^TAnd sending the data to a constellation demapping module; f. of₁ToFor any sequential combination of successively increasing doubling frequencies, f_cRepresenting a frequency of a radio frequency carrier; f. of₁ToAnd f_cThe same frequency as that of the transmitting device when modulated;

a constellation demapping module for demapping the serial signal y^TPerforming constellation demapping to obtain bit stream estimated value b^T。

The invention has the advantages that the multi-carrier transmission is realized by adopting a multi-layer orthogonal modulation mode, and the multi-carrier transmission can be realized by only 2 oscillators.

Drawings

Fig. 1 is a block diagram of a multi-layer quadrature modulation transmitting terminal according to the present invention;

fig. 2 is a block diagram of a multi-layer quadrature demodulation receiving end according to the present invention;

fig. 3 and 4 are block diagrams of generation of carrier frequencies according to the present invention;

fig. 5 and fig. 6 are schematic diagrams of multicarrier frequency spectrums obtained by the carrier frequency generation schemes of fig. 3 and fig. 4, respectively;

FIG. 7 is a graph of bit error rate comparison for a multi-layered orthogonal modulation multi-carrier architecture of the present invention with an OFDM multi-carrier architecture; eb represents energy per bit, No represents noise power spectral density;

fig. 8 is a graph comparing the spectrum utilization efficiency of the multi-layered orthogonal modulation multi-carrier structure of the present invention with that of the OFDM multi-carrier structure.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.

The multi-carrier transmission method based on multi-layer orthogonal modulation according to the present embodiment includes:

step one, as shown in fig. 1, a bit stream b is sent from a sending end^TD is obtained through constellation mapping^TThen, after serial-to-parallel conversion, M parallel signals d are generated_mParallel signal d_mPerforming pre-transformation on W to obtain M paths of complex signals x_m，m＝1，…，M；

x＝Wd＝[x₁，…，x_M]^T

For all M e {1, …, M }, x_mIs a complex signal which can be represented as x_m＝s_(2m-1)+js_2m。

Step two, the complex signal x is processed_mThe real part and the imaginary part are separated to obtain a 2M real signal s_p，p＝1，…，2M；

Step three, 2M real signal s_pObtaining a continuous time signal s through pulse shaping_p(t)；

Continuous-time signal s_p(t)＝sp*g_PS(t)。g_Ps(t) represents the time domain response of the pulse shaping filter.

Step four, for 2M path signals s_p(t) log of₂2M layer quadrature modulation, wherein the 1 st layer modulation object is 2M path signal s_p(t), the modulation object of each layer thereafter being the modulation output of the previous layer; modulation process of k layer for odd channel data utilizationTo modulate, even-term channel data utilizationAnd adds the data modulated by the odd-term channel and the adjacent next even-term channel to be one channel data of the layer modulation output, k is 1, …,log₂(2M) -1; the modulation process of the last layer is to respectively utilize the data of two channelsAndmodulating, adding the modulated data to obtain a signalWill signalSending;

as shown in FIG. 1, all 2M continuous-time signals enter the first layer of quadrature modulation, in which the frequency f is used₁Is modulated, wherein odd channel data is utilizedTo modulate, even-term channel data utilizationModulating, and adding two by two to obtain M paths of sum signals, namely for the first channel data, obtainingFor the data of the second channel, the data of the second channel is obtainedThe signals of the two channels are superimposed. For the data of the last two channels, i.e. the data of the 2M-1 and 2M channels, the data is obtainedAndthe signals of the two channels are superimposed. Through the firstThe layer quadrature modulated signal enters into the second layer quadrature modulation, similar to the first layer quadrature modulation, the signals after the first layer quadrature modulation are grouped in pairs with the frequency f₂The carrier wave of (2) is modulated, namely the initial 1 st channel data and the 2 nd channel data are superposed and usedModulating to obtain new 1 st channel data, and superposing the data of 3 rd and 4 th channels for useAnd modulating to obtain new 2 nd channel data, superposing the new two channels of data, and the like. Modulating sequentially one layer by one layer until the log of the modulation is reached, which is the same as the quadrature modulation of the second layer₂A (2M) -1 layer, the modulation frequency at this time beingAfter modulation, 2 channels of data are obtained. Then, the last layer of modulation is carried out, and the modulation frequency is f_cSo that the last 2 channels of signals are respectively composed ofAndmodulated and superimposed, the signal being in the form of

Wherein q is_p(t) represents the multi-layer quadrature modulated signal s_PCoefficient of (t), in particular form

Wherein p is 1, …, 2M, pmod2 tableThe remainder of dividing p by 2 is shown,represents the largest integer not greater than (p-1)/2.

In the present embodiment f₁ToAnd f_cFor modulating the frequency, the method for acquiring the modulation frequency comprises the following steps:

generating a frequency carrier by means of an oscillator, co-generating log on the basis of the frequency carrier₂(2M) -1 carriers of different frequencies, and log₂(2M) -1 frequency is increased by a times in sequence, f₁ToIs log₂(2M) -1 frequencies combined in an arbitrary order, f_cRepresents the frequency of the radio frequency carrier wave, and a is more than or equal to 2.

In this embodiment, only one rf oscillator, one hf/if/lf oscillator, and log are needed to achieve modulation of M carriers₂(2M) -2 frequency dividers/multipliers or a combination of frequency dividers and multipliers. This greatly reduces the multi-carrier hardware complexity compared to conventional radio frequency multi-carriers.

Parallel signal d in this embodiment_mPerforming pre-transformation to obtain M paths of complex signals x_mThe method comprises the following steps:

x＝Wd＝[x₁，…，x_M]^T

w represents a pre-transformation matrix;

when M is 2ⁿWhen W is equal to W_nIs provided with

And is

The multi-carrier reception method based on multi-layer orthogonal modulation corresponding to the transmission method in the present embodiment includes:

step five, as shown in fig. 2, the receiving end receives the signalSignalLog of₂2M layer quadrature demodulation in which the demodulation object of layer 1 is a signalThen the demodulation object of each layer is the demodulation output of the previous layer; first layer use frequency f_cPerforming quadrature demodulation to obtain two paths of outputs; layer 2 to log₂Frequency is used in 2M layer demodulationTo f₁Performing quadrature demodulation to obtain 2M path signalsp＝1，…，2M.

f₁ToAnd f_cIn order to demodulate the frequency, and the frequency is the same as the frequency when the sending end modulates, the method for obtaining the demodulation frequency is as follows: generating a frequency carrier by means of an oscillator, on the basis of which frequency carrier f is co-generated₁ToA carrier wave of frequency;

as shown in fig. 2, the signal first enters layer 1 quadrature demodulation using frequency f_cCarry out demodulation asAndtwo paths of signals which enter the layer 1 quadrature demodulation are respectively subjected to the processingAndthen 4 paths of signals are obtained, and so on. Finally, each path of signal enters the log₂(2M) layer quadrature demodulation, respectivelyAnddemodulating to obtain the final 2M path signalp＝1，…，2M。

Step six, 2M path signalObtaining a baseband continuous time signal r through a pulse forming matched filter_p(t) base band continuous time signal r_p(t) sampling to obtain a digital real signal r ═ r₁，r₂，…，r_2M]^T：

Wherein, g_MFAnd (t) represents the time domain response of each path of pulse shaping matched filter.

Step seven, every two of the 2M digital real signals form M digital complex signals z_mIs subjected to transformation W^HObtaining M paths of signals u_m，m＝1，…，M，u＝[u₁，u₂，…，u_M]^T，u＝W^Hz，z＝[z₁，…，z_M]^T＝[r₁+jr₂，…，r_2M-1+r_2M]^T，W^HRepresenting the conjugate transpose of W, wherein W represents the pre-transformation moment when the modulation front of a sending end is transformed into a complex signal;

step eight, M paths of signals u_mRespectively carrying out single-tap equalization to obtain M paths of signals y_m，y＝[y₁，y₂，…，y_M]^T，h_mFor the channel information of the mth channel obtained by channel estimation,represents h_mInverse of (2), M-way signal y_mAnd obtaining a bit stream estimated value bT through parallel-to-serial conversion and constellation demapping in sequence.

In the above description log is used₂(2M) carriers of different frequencies, respectivelyThe setting method comprises the following steps:

depending on the symbol rate R of each channel, the required bandwidth is (1+ epsilon) R, where epsilon represents the ratio of the filter transition band to the pass band, and its size is related to the filter design. This embodiment f₁Not less than B/2, the bandwidth of each signal is B, f_α≥2f_α-1，α＝2，…，log₂(2M)-1，f_cAccording to the actually required radio frequency.

In order to realize the non-spaced arrangement of a plurality of subcarriers, the modulation frequency of the first layer needs to be set to be f in the preferred embodiment₁B/2, the alpha layer quadrature modulation frequency is set to

f_α＝2f_α-1

Where α ∈ {2, …, log₂(2M) -1 }. Last layer modulation frequency f_cCan be set according to the actual radio frequency requirements. It should be noted that the above arrangementThe method is merely an example. In this example, it is assumed that the oscillator frequency used by layer 1 is the lowest, and then the modulation frequency of each layer is higher than that of the previous layer. This is for convenience only, and in fact the magnitude of α and f_αIs not related, for example, the modulation frequency of the layer 1 can be set to be the lowest (excluding the modulation frequency f of the last layer)_c) The spectrum of the signal thus subjected to multilayer quadrature modulation is shown in fig. 5. Two concepts need to be distinguished here, one being the modulation frequency f of each layer_α，(α＝1，…，log₂(2M)), the other is the subcarrier frequencyThe actual frequency of each subcarrier after modulation is

In addition, in the present embodiment, the highest modulation frequency of the layer 1 (excluding the modulation frequency f of the last layer) may be set_c) The spectrum of the signal thus subjected to multilayer quadrature modulation is shown in fig. 6. In addition to the above two specific examples, the present embodiment may further set the layer 2 modulation frequency to be the highest, the layer 3 modulation frequency to be the highest, and the like. In general, after the modulation frequencies of the layers are generated, the order of the modulation frequencies of each layer can be matched arbitrarily. Therefore, the log of the increase by a times in the present embodiment₂(2M) -1 carriers of different frequencies, f₁ToIs log₂(2M) -1 frequency are combined in any order.

After the modulation frequencies of each layer are set, the carriers required to generate the frequencies can be generated by the following method:

the method comprises the following steps: referring to FIG. 3, a low frequency oscillator generates a frequency f₁Then using a frequency doubler to obtain the carrier wave with the frequency f₂The carrier wave is obtained by a frequency doubler to obtain the frequency f₃＝2f₂The carrier wave of (2) can be obtained by analogy, and the frequency isCan finally generate the carrier wave with the frequency f by using a high-frequency oscillator_cThe radio frequency carrier of (1). Such a total of 1 low frequency oscillator, one radio frequency oscillator and log is required₂(2M) -2 frequency multipliers.

The second method comprises the following steps: as shown in FIG. 4, a high frequency oscillator generates a frequency ofThen a frequency of the carrier wave is obtained by using a frequency divider of twoThe carrier wave of (2) is obtained by a frequency divider of two frequenciesThe carrier wave of (2) can be obtained by analogy in turn with the frequency f₁Can finally generate the carrier wave with the frequency f by using a high-frequency oscillator_cThe radio frequency carrier of (1). Such a total of 1 HF oscillator, one RF oscillator and log is required₂(2M) -2 frequency dividers.

Generating a 1 st frequency carrier by using an intermediate frequency oscillator, generating a 2 nd frequency carrier by the 1 st frequency carrier through a frequency divider, inputting the 2 nd frequency carrier into a second frequency divider to generate a 3 rd frequency carrier, and repeating the steps until a b th frequency carrier is generated;

the first frequency carrier generates the (b + 1) th frequency carrier through a frequency multiplier, the (b + 1) th frequency carrier is input into a second frequency multiplier to generate the (b + 2) th frequency carrier, and so on until the log is generated₂(2M) -1 frequency carrier;

using a radio-frequency oscillator to generate a frequency f_cThe radio frequency carrier of (1).

Table 1 shows a comparison between the area and power consumption of the radio frequency chip required by the multi-carrier transmission method of the present embodiment and the conventional radio frequency multi-carrier, as shown in table 1, when the number of carriers is the same, both the area and power consumption of the radio frequency chip required by the present embodiment are superior to those of the conventional radio frequency multi-carrier, and the larger the number of carriers is, the greater the advantage is.

Table 1 radio frequency complexity contrast

Meanwhile, the embodiment also has a great number of defects of OFDM, such as the need of CP, high out-of-band leakage, high PAPR and the like. Fig. 7 shows the bit error rate comparison between the embodiment and OFDM under the same channel condition. Simulations used uncoded QPSK with 64 carriers and 72, 76, 80 OFDM symbol lengths when CP lengths were 8, 12, 16 respectively. The delay spread of the channel in the simulation is 15 and 16 paths of equal power, which are independent of each other and all follow rayleigh distribution. When the CP length is 16, the CP length just exceeds the channel delay spread, so OFDM exhibits the same bit error rate as the present embodiment, and when the CP length is less than the delay spread, OFDM exhibits significant performance degradation, as shown in fig. 7. Fig. 8 compares the spectrum utilization efficiency of two multicarrier schemes under the same channel condition. It can be seen that the spectral efficiency of the embodiment is higher than that of the OFDM scheme. Under the condition that the CP length is smaller than the delay spread, the bit error rate performance of the method is better than that of the OFDM, and the spectrum utilization efficiency is better than that of the OFDM scheme.

The multi-carrier transmission apparatus based on multilevel orthogonal modulation according to the present embodiment includes:

a constellation mapping module connected with the serial-to-parallel conversion module for mapping the bit stream b^TPerforming constellation mapping to obtain a signal d^TSending the data to a serial-parallel conversion module;

a serial-to-parallel conversion module connected with the multi-layer IQ modulation module for converting the signal d^TPerforming serial-to-parallel conversion to generate M parallel signals d_mParallel signal d_mSending the data to a multi-layer IQ modulation module;

frequency generation module, and multi-layer IQ modulatorA module connection for generating a frequency carrier by means of an oscillator, on the basis of which frequency carrier log is co-generated₂(2M) -1 carriers of different frequencies, and log₂Increasing the (2M) -1 frequency by a times in sequence, and dividing log₂(2M) -1 frequencies are combined in an arbitrary order as a modulation frequency f₁Toa is more than or equal to 2, and the frequency generated by the radio frequency oscillator is f_cRadio frequency carrier of, will f₁ToAnd f_cSending the data to a multi-layer IQ modulation module;

a multi-layer IQ modulation module connected with the transmitting antenna and used for the M paths of parallel signals d_mPerforming pre-transformation on W to obtain M paths of complex signals x_mM is 1, …, M; 2M real signal s_pObtaining a continuous time signal s through pulse shaping_p(t); for 2M signals s_p(t) log of₂2M layer quadrature modulation, wherein the 1 st layer modulation object is 2M path signal s_p(t), the modulation object of each layer thereafter being the modulation output of the previous layer; modulation process of k layer for odd channel data utilizationTo modulate, even-term channel data utilizationModulating, and adding the data modulated by the odd-numbered channel and the adjacent next even-numbered channel to be used as channel data of the layer modulation output; k is 1, …, log₂(2M) -1; the modulation process of the last layer is to respectively utilize the data of two channelsAndto modulate the optical signal to be modulated,adding the modulated data to obtain a signalAnd sending to a sending antenna;

transmitting antenna for transmitting signalAnd (5) sending.

The multi-carrier receiving apparatus according to the present embodiment based on multilevel orthogonal modulation includes:

a receiving antenna connected with the multi-layer IQ demodulation module for receiving signals at the receiving endAnd sending to a multi-layer IQ demodulation module;

a frequency generation module connected with the multi-layer IQ demodulation module and used for generating a frequency carrier by using the oscillator and generating f together on the basis of the frequency carrier₁ToA carrier wave of frequency; using a radio frequency oscillator to generate a frequency f_cRadio frequency carrier of, will f₁ToAnd f_cSending the data to a multilayer IQ demodulation module; f. of₁ToAnd f_cThe frequency is a demodulation frequency and is the same as the frequency when the sending end modulates;

multi-layered IQ demodulation module, connected to single-tap equalizer, for receiving signalsLog of₂2M layer quadrature demodulation in which the demodulation object of layer 1 is a signalThen the demodulation object of each layer is the demodulation output of the previous layer; first layer use frequency f_cPerforming quadrature demodulation to obtain two paths of outputs; layer 2 to log₂Frequency is used in 2M layer demodulationTo f₁Performing quadrature demodulation to obtain 2M path signalsp ═ 1, …, 2M; 2M path signalObtaining a baseband continuous time signal r through a pulse forming matched filter_p(t) base band continuous time signal r_p(t) sampling to obtain a digital real signal r ═ r₁，r₂，…，r_2M]^T(ii) a The 2M digital real signals are grouped into M digital complex signals z_mIs subjected to transformation W^HObtaining M paths of signals u_m，u＝[u₁，u₂，…，u_M]^T，u＝W^Hz，z＝[z₁，z₂，…，z_M]^T，W^HDenotes the conjugate transpose of W, W denotes the pre-transform matrix when transforming to complex signal before modulation at the transmitting end, and M paths of signals u_mSending to a single tap equalizer; m is 1, …, M;

a single-tap equalizer connected with the serial-parallel conversion module and used for respectively carrying out single-tap equalization on the M paths of signals um to obtain M paths of signals y_m，y＝[y₁，y₂，…，y_M]^TAnd will combine the M signals y_mSending the data to a serial-parallel conversion module;

a serial-parallel conversion module connected with the constellation demapping module and used for converting the M paths of signals y_mThrough parallel-to-serial conversion, a path of serial signal y is obtained^TAnd sending the data to a constellation demapping module; f. of₁ToFor any sequential combination of successively increasing doubling frequencies, f_cRepresenting a frequency of a radio frequency carrier; f. of₁ToAnd f_cThe same frequency as that of the transmitting device when modulated;

a constellation demapping module for demapping the serial signal y^TPerforming constellation demapping to obtain bit stream estimated value b^T。

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.