阅读说明：本技术 一种基于离散导频辅助的频偏估计方法及装置 (A kind of frequency deviation estimating method and device based on scattered pilot auxiliary ) 是由 李薿 于 2019-07-12 设计创作，主要内容包括：一种基于离散导频辅助的频偏估计方法,从接收信号中抽取出所有可用离散导频符号；对所述可用离散导频符号进行去调制处理,获得去调制离散导频符号；对所述去调制离散导频符号进行补0处理,使其成为一个长度为2<Sup>u</Sup>的符号串,其中,u为整数；对所述字符串进行2<Sup>u</Sup>点FFT变换；计算变换后的字符串的模长；查找模长最大的点所在位置；根据所述位置计算接收信号的频偏估计。基于离散导频辅助的频偏估计装置,包括抽取模块、去调制模块、成串模块、变换模块、模长计算模块、查找模块、估计模块。本方法/装置在E<Sub>s</Sub>/N<Sub>0</Sub>为-2dB的条件下充分的利用了离散导频的特点,仅用4096的FFT长度即可达到10^(-5)的误差精度,效率高,计算复杂度低,利于工程实现,满足DVB-RCS2的帧格式解调要求。(A kind of frequency deviation estimating method based on scattered pilot auxiliary extracts all available scattered pilot symbols from receiving in signal；Modulation treatment can be carried out with scattered pilot symbol to described, modulation scattered pilot symbol is removed in acquisition；Modulation scattered pilot symbol is gone to carry out mending 0 processing to described, becoming a length is 2 u Symbol string, wherein u is integer；2 are carried out to the character string u Point FFT transform；The mould for calculating transformed character string is long；Search the long maximum position of mould；The offset estimation for receiving signal is calculated according to the position.Based on the frequency deviation estimation device of scattered pilot auxiliary, including abstraction module, remove modulation module, bunchiness module, conversion module, the long computing module of mould, searching module, estimation module.This method/device is in E s /N 0 The characteristics of for scattered pilot is adequately utilized under conditions of -2dB is only the error precision that can reach 10^ (- 5) with 4096 FFT length, and high-efficient, computation complexity is low, is conducive to Project Realization, and the frame format demodulation for meeting DVB-RCS2 requires.)

1. a kind of frequency deviation estimating method based on scattered pilot auxiliary, which comprises the following steps:

All available scattered pilot symbols are extracted from receiving in signal；

Modulation treatment can be carried out with scattered pilot symbol to described, modulation scattered pilot symbol is removed in acquisition；

Modulation scattered pilot symbol is gone to carry out mending 0 processing to described, becoming a length is 2^uSymbol string, wherein u is Integer；

2 are carried out to the character string^uPoint FFT transform；

The mould for calculating transformed character string is long；

Search the long maximum position of mould；

The offset estimation for receiving signal is calculated according to the position.

2. the frequency deviation estimating method according to claim 1 based on scattered pilot auxiliary, which is characterized in that the extraction, It further include extracting the leading available points led with after, and be included in available scattered pilot symbol together after extraction.

3. the frequency deviation estimating method according to claim 1 based on scattered pilot auxiliary, which is characterized in that described to go to modulate Processing, is that modulation treatment: d (k)=z (k) can be carried out with scattered pilot symbol to described by local scattered pilot symbol c^*(k), wherein c^*(k) conjugation for being local frequency pilot sign c (k).

4. the frequency deviation estimating method according to claim 1 based on scattered pilot auxiliary, it is characterised in that:

The long maximum position of mould is searched, and sets the position as k_max；

The offset estimation for receiving signal passes throughIt calculates.

5. a kind of frequency deviation estimation device based on scattered pilot auxiliary characterized by comprising

Abstraction module, for extracting all available scattered pilot symbols from reception signal；

Modulation module is removed, for that can carry out modulation treatment with scattered pilot symbol to described, modulation scattered pilot symbol is removed in acquisition Number；

Bunchiness module, for going modulation scattered pilot symbol to carry out mending 0 processing to described, becoming a length is 2^uSymbol Number string, wherein u is integer；

Conversion module, for carrying out 2 to the character string^uPoint FFT transform；

The long computing module of mould, the mould for calculating transformed character string are long；

Searching module, for searching the long maximum position of mould；

Estimation module, for calculating the offset estimation for receiving signal according to the position.

6. the frequency deviation estimation device according to claim 5 based on scattered pilot auxiliary, which is characterized in that the extraction mould Block is also used to extract the leading available points led with after, and is included in available scattered pilot symbol together after extraction.

7. the frequency deviation estimation device according to claim 5 based on scattered pilot auxiliary, which is characterized in that described to go to modulate Module is that modulation treatment: d (k)=z (k) can be carried out with scattered pilot symbol to described by local scattered pilot symbol c^*(k), wherein c^*(k) conjugation for being local frequency pilot sign c (k).

8. the frequency deviation estimation device according to claim 5 based on scattered pilot auxiliary, which is characterized in that

The searching module for searching the long maximum position of mould, and sets the position as k_max；

The estimation module, passes throughCalculate the offset estimation for receiving signal.

Technical field

The present invention relates to Carrier Synchronization more particularly to a kind of frequency deviation estimating methods and dress based on scattered pilot auxiliary It sets.

Background technique

In digital communication systems, demodulation mode determines the performance of digital modulation system.Frequency Synchronization in carrier synchronization It is an indispensable part in digital communication system, the damage of frequency deviation caused by compensating for signal in transmission process.Frequency deviation Estimated accuracy is higher, and the demodulation subsequent step of signal is simpler, especially for the scattered pilot of the burst communication of DVB-RCS2 Mode, the requirement to frequency deviation precision are high.But DVB-RCS2 it is leading, after lead very short, current existing frequency excursion algorithm is only Can using it is leading or after the symbolic information led, and under the conditions of the frame format of DVB-RCS2, these methods calculate carrier frequency Error precision far from reaching requirement.

Summary of the invention

The problems such as requirement in order to solve the frequency deviation precision mentioned in related art is high, the present invention provides one kind and is based on The frequency deviation estimating method and device of scattered pilot auxiliary, suitable for the scattered pilot frame format of DVB-RCS2, frequency offset estimation accuracy Height, stability is good, and computation complexity is low, is easy to be engineered.

To achieve the goals above, the present invention uses following technology:

Design philosophy are as follows:

Receiving end is extracted out from synchronization signal one by one after receiving symbol, by scattered pilot, is formed a string and is not changed original The pilot samples signal of signal characteristic.Go to modulate by scattered pilot symbol of the local scattered pilot symbol to extraction, then into Row 2^uThe FFT transform of point, then position proportional of the maximum point of spectrum amplitude in the overall situation represents two adjacent scattered pilots Between relative frequency deviation, to calculate the relative frequency deviation received in signal between adjacent-symbol.

A kind of frequency deviation estimating method based on scattered pilot auxiliary provided by the invention, which is characterized in that including following step It is rapid:

All available scattered pilot symbols are extracted from receiving in signal；

Modulation treatment can be carried out with scattered pilot symbol to described, modulation scattered pilot symbol is removed in acquisition；

Modulation scattered pilot symbol is gone to carry out mending 0 processing to described, becoming a length is 2^uSymbol string, In, u is integer；

2 are carried out to the character string^uPoint FFT transform；

The mould for calculating transformed character string is long；

Search the long maximum position of mould；

The offset estimation for receiving signal is calculated according to the position.

Further, the extraction, further include extract it is leading and after the available points led, and be included in together after extraction available Scattered pilot symbol.

Further, described to go modulation treatment, be by local scattered pilot symbol to it is described with scattered pilot symbol into Row goes modulation treatment: d (k)=z (k) c^*(k), wherein c^*(k) conjugation for being local frequency pilot sign c (k).

Further, the long maximum position of mould is searched, and sets the position as k_max；The offset estimation for receiving signal is logical It crossesIt calculates.

A kind of frequency deviation estimation device based on scattered pilot auxiliary provided by the invention characterized by comprising

Abstraction module, for extracting all available scattered pilot symbols from reception signal；

Modulation module is removed, for that can carry out modulation treatment with scattered pilot symbol to described, acquisition goes to modulate discrete lead Frequency symbol；

Bunchiness module, for going modulation scattered pilot symbol to carry out mending 0 processing to described, becoming a length is 2^u Symbol string, wherein u is integer；

Conversion module, for carrying out 2 to the character string^uPoint FFT transform；

The long computing module of mould, the mould for calculating transformed character string are long；

Searching module, for searching the long maximum position of mould；

Estimation module, for calculating the offset estimation for receiving signal according to the position.

Further, the abstraction module is also used to extract the leading available points led with after, and is included in together after extraction Available scattered pilot symbol.

Further, described to remove modulation module, be by local scattered pilot symbol to it is described with scattered pilot symbol into Row goes modulation treatment: d (k)=z (k) c^*(k), wherein c^*(k) conjugation for being local frequency pilot sign c (k).

Further, the searching module for searching the long maximum position of mould, and sets the position as k_max；It is described Estimation module passes throughCalculate the offset estimation for receiving signal.

The invention has the advantages that:

In E_s/N₀The characteristics of for scattered pilot is adequately utilized under conditions of -2dB, only with 4096 FFT length Reach the error precision of 10^ (- 5), high-efficient, computation complexity is low, is conducive to Project Realization, meets the frame format solution of DVB-RCS2 It adjusts and requires.

Detailed description of the invention

Fig. 1 is DVB-RCS2 scattered pilot frame format figure.

Fig. 2 is the flow chart of embodiment of the present invention method.

Fig. 3 is the structure chart of apparatus of the present invention embodiment.

Fig. 4 is the comparison diagram of resulting frequency offset error curve and MCRB curve of the embodiment of the present invention.

Specific embodiment

Below in conjunction with the attached drawing in the embodiment of the present application, technical solutions in the embodiments of the present application carries out clear, complete Site preparation description, it is clear that described embodiments are only a part of embodiments of the present application, instead of all the embodiments.

As shown in Figure 1, being DVB-RCS2 scattered pilot frame format figure.

In embodiment:

If received burst signal length is L, d, a total of n are divided between scattered pilot_scA scattered pilot, channel condition For AWGN.

It is illustrated in figure 2 the flow chart of the frequency deviation estimating method embodiment assisted the present invention is based on scattered pilot.

The first step extracts all available scattered pilot symbols out.

In addition to all scattered pilot points, it is leading, after lead and can also additionally extract scattered pilot, it is assumed that it is leading can snap shot number For n_pr, after lead can snap shot number be n_po.Then total available scattered pilot symbol points are

N=n_sc+n_pr+n_po。

All available scattered pilot symbols are gone to modulate by second step.The modulated available scattered pilot symbol is gone to be

D (k)=z (k) c^*(k)。

Wherein, c^*(k) conjugation for being local frequency pilot sign c (k).

Third step, to going the available scattered pilot symbol of modulation to carry out mending 0 operation, becoming a length is 2^u's Symbol string, wherein u is integer.

The symbol string of third step is carried out 2 by the 4th step^uPoint FFT transform.

5th step, calculate the 4th step in it is transformed after symbol string mould it is long.

6th step searches maximum point in the 5th step, if its position is k_max。

7th step, the offset estimation for receiving signal are

It is illustrated in figure 3 the structure chart of the frequency deviation estimation device embodiment assisted the present invention is based on scattered pilot.

Device includes:

Abstraction module, for extracting all available scattered pilot symbols from reception signal；The abstraction module, is also used In the leading available points led with after of extraction, and it is included in available scattered pilot symbol together after extraction；

Modulation module is removed, for that can carry out modulation treatment with scattered pilot symbol to described, acquisition goes to modulate discrete lead Frequency symbol；It is described to remove modulation module, it is with scattered pilot symbol can modulate to described by local scattered pilot symbol Processing: d (k)=z (k) c^*(k), wherein c^*(k) conjugation for being local frequency pilot sign c (k)；

Bunchiness module, for going modulation scattered pilot symbol to carry out mending 0 processing to described, becoming a length is 2^u Symbol string, wherein u is integer；

Conversion module, for carrying out 2 to the character string^uPoint FFT transform；

The long computing module of mould, the mould for calculating transformed character string are long；

Searching module for searching the long maximum position of mould, and sets the position as k_max；

Estimation module, for calculating the offset estimation for receiving signal according to the position, calculation formula is

The method of above-described embodiment and/or device are applied to the offset estimation of scattered pilot auxiliary, frequency deviation is can get and misses The comparison diagram of poor curve and MCRB curve, as shown in Figure 4.It wherein, is DVB-RCS2 mark for the physical frame formats of Performance Evaluation Certainly adopted waveform: WaveformID=43 ([email protected]/2).FFT length be 4096, simulation run 1000 times.

This method/the present apparatus, in E_s/N₀The characteristics of for scattered pilot is adequately utilized under conditions of -2dB, only with 4096 FFT length be that can reach the error precision of 10^ (- 5), high-efficient, computation complexity is low, is conducive to Project Realization, meets DVB- The frame format of RCS2, which demodulates, to be required.