CN115801186B - Burst communication Turbo decoding method based on feedback iteration - Google Patents
Burst communication Turbo decoding method based on feedback iteration Download PDFInfo
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Abstract
The invention belongs to the technical field of burst communication and Turbo decoding processing, and discloses a burst communication Turbo decoding method based on feedback iteration. The invention does not need to lengthen the length of scattered pilot frequency in the data pulse under low signal-to-noise ratio, thereby avoiding information redundancy and transmission efficiency reduction caused by adding the scattered pilot frequency, saving time slot resources and frequency resources of the system and ensuring the effective utilization rate of the resources of the system; by feedback iteration, effective data in the data pulse is utilized for accumulation, so that a high sum vector signal-to-noise ratio is obtained, the accuracy of data demodulation is improved, the error rate after demodulation and decoding is reduced, and the receiving sensitivity of the system is effectively improved.
Description
Technical Field
The invention belongs to the technical field of burst communication and Turbo decoding processing, and relates to a burst communication Turbo decoding method based on feedback iteration.
Background
In wireless communications, coding is generally used to achieve reliable transmission of data at low signal-to-noise ratio, turbo coding is a common forward error correction (Forward Error Correction, FEC) technique, which combines convolutional codes with random interleavers, implements random coding while implementing short code construction long codes by the interleavers, and employs soft output iterative decoding to approximate maximum likelihood decoding. The Turbo code fully utilizes the basic condition of the Shannon channel coding theorem to obtain the performance close to the Shannon limit, so that the Turbo code has wider application.
For burst communication under a complex electromagnetic environment, channel parameter estimation is generally realized by inserting scattered pilot frequency into data pulse, and demodulation of data is realized by conjugate matching of the scattered pilot frequency and vector and the data. In military communication, in order to save the additional overhead brought by scattered pilots and improve the transmission efficiency of signals, the length of the scattered pilots is usually set to be short, the signal to noise ratio of the scattered pilots and the vector is positively correlated with the accumulated length of the scattered pilots and negatively correlated with the signal demodulation error rate, so that the problem that the transmission efficiency in burst communication is inconsistent with the demodulation threshold is brought, and even if Turbo coding with extremely low code rate is used, high-sensitivity demodulation and decoding cannot be realized under the conditions of low signal to noise ratio and short length of the scattered pilots.
Disclosure of Invention
Object of the invention
The purpose of the invention is that: aiming at the defects of poor demodulation and decoding effects caused by insufficient signal-to-noise ratio of scattered pilot frequency in traditional burst communication, the method is provided, which does not need to increase the length of the scattered pilot frequency, enables a receiving end to perform feedback iteration through a Turbo code, and utilizes data symbols and the scattered pilot frequency to uniformly calculate a sum vector, and effectively improves the receiving sensitivity of the system on the premise of ensuring the transmission efficiency of the system.
(II) technical scheme
In order to solve the technical problems, the invention provides a burst communication Turbo decoding method based on feedback iteration, which specifically comprises the following steps:
step one, after receiving signals, a receiver performs down-conversion and sampling;
The down-conversion output is a complex signal with data modulation, the sampling rate is f s, the sampling result is a baseband sampling sequence with data and scattered pilot frequency modulation, and the baseband sampling sequence can be represented by the following formula (1):
Wherein N represents an nth sampling point, n=n c+Nd is a single data pulse sampling point, N c is a scattered pilot sampling point, and N d is an effective data sampling point; t s＝1/fs is a time domain sampling interval, D (nt s) represents a modulation signal at a sampling moment of nt s, and the modulation signal is binary data, wherein the binary data comprises scattered pilot frequency c (n cts) and effective data D (n dts),nc and n d respectively represent sampling point positions corresponding to the scattered pilot frequency and the effective data; exp represents power series with e as a base; j represents an imaginary unit; The initial phase of the radio frequency carrier wave is set; n 0 denotes gaussian white noise present in the received signal.
Step two, according to the appointed positions of the receiving and transmitting ends, scattered pilot frequencies in the data pulse are selected, and the scattered pilot frequencies are matched with the local pseudo-random sequence and then the sum vector is obtained;
The scattered pilot frequency is assumed to be located at N c sampling points before the data pulse, the scattered pilot frequency is multiplied by a local pseudo-random sequence c (N) to eliminate the polarity of the scattered pilot frequency, and the vector sum is calculated and expressed by the following formula (2):
Wherein, To obtain the initial phase estimation value of the radio frequency carrier under the influence of noise by using scattered pilot frequency.
Step three, the conjugate of the sum vector obtained in the step two is obtained and matched with the effective data of N d sampling points, so that data demodulation is completed, and the data demodulation is represented by the following formula (3):
Wherein (-) * represents the conjugate, And the data estimation value after demodulation is completed for the effective data.
Step four, demodulating the data obtained in the step threeAnd performing Turbo decoding to obtain a decoded original information bit estimation result d 0.
And fifthly, re-encoding the original information bit estimation result d 0 decoded in the step four according to a corresponding encoding mode, obtaining encoded data d 'and storing the encoded data d'.
Step six, the recoded data d' and the demodulated data obtained in the step three are processedAnd performing symbol-by-symbol comparison, searching and storing the position with the same polarity, and recording as L d.
Step seven, according to the recording position L d, selecting the effective data in the position in the data pulse r (n), multiplying the effective data with the coded data d' in the same position point by point, and obtaining the vector sum as shown in the following formula (4):
Wherein, To obtain an initial phase estimation value of a radio frequency carrier under the influence of noise by using data symbols.
Step eight, adding the scattered pilot frequency and the data symbol twice to the vector C s、Ds, obtaining a final sum vector, obtaining a conjugate, matching with effective data of N d sampling points, and finishing data feedback iterative demodulation, wherein the formula (5) is as follows:
Wherein, The initial phase estimate is the final rf carrier.
Step nine, demodulating the data obtained in step eightAnd performing Turbo decoding again to obtain a decoded original information bit estimation result d 0'.
(III) beneficial effects
Compared with the traditional burst communication demodulation and decoding modes, the burst communication Turbo decoding method based on feedback iteration has the following beneficial effects:
1. Under the condition of low signal-to-noise ratio, the length of scattered pilot frequency in the data pulse is not required to be lengthened, the information redundancy and the reduction of transmission efficiency caused by the addition of the scattered pilot frequency are avoided, the time slot resources and the frequency resources of the system are saved, and the effective utilization rate of the resources of the system is ensured;
2. By feedback iteration, effective data in the data pulse is utilized for accumulation, so that a high sum vector signal-to-noise ratio is obtained, the accuracy of data demodulation is improved, the error rate after demodulation and decoding is reduced, and the receiving sensitivity of the system is effectively improved.
Drawings
FIG. 1 is a schematic block diagram of a burst communication Turbo decoding method based on feedback iteration of the invention;
fig. 2 is a graph of bit error rate simulation statistics comparing the burst communication Turbo decoding method based on feedback iteration of the invention with the traditional demodulation and decoding method under different signal to noise ratios.
Detailed Description
To make the objects, contents and advantages of the present invention more apparent, the following detailed description of the present invention will be given with reference to the accompanying drawings and examples.
Referring to fig. 1 and 2, the burst communication Turbo decoding method based on feedback iteration in this embodiment specifically includes the following steps:
step one, after receiving signals, a receiver performs down-conversion and sampling;
The down-conversion output is a complex signal with data modulation, the sampling rate is f s, the sampling result is a baseband sampling sequence with data and scattered pilot frequency modulation, and the baseband sampling sequence can be represented by the following formula (1):
Wherein N represents an nth sampling point, n=n c+Nd is a single data pulse sampling point, N c is a scattered pilot sampling point, and N d is an effective data sampling point; t s＝1/fs is a time domain sampling interval, D (nt s) represents a modulation signal at a sampling moment of nt s, and the modulation signal is binary data, wherein the binary data comprises scattered pilot frequency c (n cts) and effective data D (n dts),nc and n d respectively represent sampling point positions corresponding to the scattered pilot frequency and the effective data; exp represents power series with e as a base; j represents an imaginary unit; The initial phase of the radio frequency carrier wave is set; n 0 denotes gaussian white noise present in the received signal.
Step two, according to the appointed positions of the receiving and transmitting ends, scattered pilot frequencies in the data pulse are selected, and the scattered pilot frequencies are matched with the local pseudo-random sequence and then the sum vector is obtained;
The scattered pilot frequency is assumed to be located at N c sampling points before the data pulse, the scattered pilot frequency is multiplied by a local pseudo-random sequence c (N) to eliminate the polarity of the scattered pilot frequency, and the vector sum is calculated and expressed by the following formula (2):
Wherein, To obtain the initial phase estimation value of the radio frequency carrier under the influence of noise by using scattered pilot frequency.
Step three, the conjugate of the sum vector obtained in the step two is obtained and matched with the effective data of N d sampling points, so that data demodulation is completed, and the data demodulation is represented by the following formula (3):
Wherein (-) * represents the conjugate, And the data estimation value after demodulation is completed for the effective data.
Step four, demodulating the data obtained in the step threeAnd performing Turbo decoding to obtain a decoded original information bit estimation result d 0.
And fifthly, re-encoding the original information bit estimation result d 0 decoded in the step four according to a corresponding encoding mode, obtaining encoded data d 'and storing the encoded data d'.
Step six, the recoded data d' and the demodulated data obtained in the step three are processedAnd performing symbol-by-symbol comparison, searching and storing the position with the same polarity, and recording as L d.
Step seven, according to the recording position L d, selecting the effective data in the position in the data pulse r (n), multiplying the effective data with the coded data d' in the same position point by point, and obtaining the vector sum as shown in the following formula (4):
Wherein, To obtain an initial phase estimation value of a radio frequency carrier under the influence of noise by using data symbols.
Step eight, adding the scattered pilot frequency and the data symbol twice to the vector C s、Ds, obtaining a final sum vector, obtaining a conjugate, matching with effective data of N d sampling points, and finishing data feedback iterative demodulation, wherein the formula (5) is as follows:
Wherein, The initial phase estimate is the final rf carrier.
Step nine, demodulating the data obtained in step eightAnd performing Turbo decoding again to obtain a decoded original information bit estimation result d 0'.
Thus, the burst communication Turbo decoding method based on feedback iteration is completed from the first step to the ninth step.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and variations could be made by those skilled in the art without departing from the technical principles of the present invention, and such modifications and variations should also be regarded as being within the scope of the invention.
Claims (4)
1. A burst communication Turbo decoding method based on feedback iteration is characterized by comprising the following steps:
step one, after receiving signals, a receiver performs down-conversion and sampling;
step two, according to the appointed positions of the receiving and transmitting ends, scattered pilot frequencies in the data pulse r (n) are selected, and after matching with the local pseudo-random sequence, a sum vector is obtained;
Step three, the conjugate of the sum vector obtained in the step two is obtained and matched with the effective data of N d sampling points, so that data demodulation is completed;
step four, demodulating the data obtained in the step three Performing Turbo decoding to obtain a decoded original information bit estimation result d 0;
Re-encoding the original information bit estimation result d 0 decoded in the fourth step according to a corresponding encoding mode, obtaining encoded data d 'and storing the encoded data d';
step six, the recoded data d' and the demodulated data obtained in the step three are processed Performing symbol-by-symbol comparison, searching and storing the position with the same polarity, and recording as L d;
Step seven, according to the recording position L d, selecting the effective data in the position in the data pulse r (n), multiplying the effective data with the coded data d' in the same position point by point, and obtaining a sum vector;
Step eight, adding the sum vectors obtained in the step two and the step seven twice, obtaining a final sum vector, obtaining a conjugate, and matching with the effective data of N d sampling points to finish data feedback iterative demodulation;
Step nine, demodulating the data obtained in step eight Performing Turbo decoding again to obtain a decoded original information bit estimation result d' 0;
in the first step, the down-conversion output is a complex signal with data modulation, the sampling rate is f s, and the sampling result is a baseband sampling sequence with data and scattered pilot frequency modulation;
in step one, the baseband sampling sequence is represented by the following formula (1):
Wherein N represents an nth sampling point, n=n c+Nd is a single data pulse sampling point, N c is a scattered pilot sampling point, and N d is an effective data sampling point; t s＝1/fs is a time domain sampling interval, D (nt s) represents a modulation signal at a sampling moment of nt s, and the modulation signal is binary data, wherein the binary data comprises scattered pilot frequency c (n cts) and effective data D (n dts),nc and n d respectively represent sampling point positions corresponding to the scattered pilot frequency and the effective data; exp represents power series with e as a base; j represents an imaginary unit; the initial phase of the radio frequency carrier wave is set; n 0 denotes gaussian white noise present in the received signal;
In the second step, assuming that scattered pilots are located at N c sampling points before a data pulse, multiplying the scattered pilots with a local pseudo-random sequence c (N) by corresponding sampling points, then eliminating the polarity of the scattered pilots, and obtaining a vector sum as shown in the following formula (2):
Wherein, To obtain the initial phase estimation value of the radio frequency carrier under the influence of noise by using scattered pilot frequency.
2. The burst communication Turbo decoding method based on feedback iteration as claimed in claim 1, wherein in the third step, the demodulated data is represented by the following formula (3):
Wherein (-) * represents the conjugate, And the data estimation value after demodulation is completed for the effective data.
3. The burst communication Turbo decoding method based on feedback iteration as claimed in claim 2, wherein in step seven, the sum vector is expressed by the following formula (4):
Wherein, To obtain an initial phase estimation value of a radio frequency carrier under the influence of noise by using data symbols.
4. The burst communication Turbo decoding method based on feedback iteration as claimed in claim 3, wherein in the eighth step, the demodulation data is represented by the following formula (5):
Wherein, The initial phase estimate is the final rf carrier.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2470546A1 (en) * | 2003-06-13 | 2004-12-13 | The Directv Group, Inc. | Method and apparatus for providing carrier synchronization in digital broadcast and interactive systems |
| CN1677877A (en) * | 2004-03-31 | 2005-10-05 | 清华大学 | Assembly structure of time-domain synchronous orthogonal frequency-division multiplex receiver |
| CN101420234A (en) * | 2008-12-09 | 2009-04-29 | 山东大学 | Windowed MAP decoding method and system for unitary space-time symbol stage Turbo code |
| CN102124706A (en) * | 2008-06-17 | 2011-07-13 | 爱立信电话股份有限公司 | Receiver and method for processing radio signals using soft pilot symbols |
| CN102714645A (en) * | 2010-01-13 | 2012-10-03 | 松下电器产业株式会社 | Pilot patterns for OFDM systems with multiple antennas |
| CN103490860A (en) * | 2013-10-11 | 2014-01-01 | 中国人民解放军理工大学 | Iterative demodulating and decoding method for high-performance shortwave orthogonal spectrum spreading |
| CN110071756A (en) * | 2019-04-28 | 2019-07-30 | 西安空间无线电技术研究所 | A kind of rotor block under burst signal detection and carrier synchronization method |
-
2022
- 2022-10-27 CN CN202211324397.0A patent/CN115801186B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2470546A1 (en) * | 2003-06-13 | 2004-12-13 | The Directv Group, Inc. | Method and apparatus for providing carrier synchronization in digital broadcast and interactive systems |
| CN1677877A (en) * | 2004-03-31 | 2005-10-05 | 清华大学 | Assembly structure of time-domain synchronous orthogonal frequency-division multiplex receiver |
| CN102124706A (en) * | 2008-06-17 | 2011-07-13 | 爱立信电话股份有限公司 | Receiver and method for processing radio signals using soft pilot symbols |
| CN101420234A (en) * | 2008-12-09 | 2009-04-29 | 山东大学 | Windowed MAP decoding method and system for unitary space-time symbol stage Turbo code |
| CN102714645A (en) * | 2010-01-13 | 2012-10-03 | 松下电器产业株式会社 | Pilot patterns for OFDM systems with multiple antennas |
| CN103490860A (en) * | 2013-10-11 | 2014-01-01 | 中国人民解放军理工大学 | Iterative demodulating and decoding method for high-performance shortwave orthogonal spectrum spreading |
| CN110071756A (en) * | 2019-04-28 | 2019-07-30 | 西安空间无线电技术研究所 | A kind of rotor block under burst signal detection and carrier synchronization method |
Non-Patent Citations (4)
| Title |
|---|
| Low-Complexity Decoding of Repeat-Accumulate Codes over Quasi-Static Fading Channels;Haifeng Yuan等;《2015 IEEE Global Communications Conference (GLOBECOM)》;20160225;全文 * |
| LTE通信系统中的定位技术研究;郎为民;王大鹏;吴帆;;电信快报;20160710(第07期);全文 * |
| 基于迭代补偿的快速突发信道估计算法;姚磊;李赞;蔡觉平;张海林;万佳君;;电子学报;20100415(第04期);全文 * |
| 宽带无线OFDM系统中ICI抑制技术研究;吴皓威;《中国优秀博士学位论文全文数据库》;20130215;全文 * |
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