阅读说明：本技术 一种宽带数据传输中的频率选择性衰落补偿方法及装置 (Frequency selective fading compensation method and device in broadband data transmission ) 是由 王利平 于 2021-08-31 设计创作，主要内容包括：本发明公开了一种宽带数据传输中的频率选择衰落补偿方法及装置,属于宽带数字通信技术领域。本发明提出的补偿处理是在对输入信号模数转换、数字变频、滤波以及同步基础上进行的,其利用信道传输数据帧中的训练序列进行补偿系数计算,然后通过滑动相乘、累加运算完成补偿处理,显著提高了宽带数据传输系统对频率选择性衰落的对抗能力。本发明具有功耗低、资源利用率高、运算速度快、易于扩展、利于并行处理等优点,可广泛应用于雷达、通信、测控等宽带数字接收机中。(The invention discloses a frequency selective fading compensation method and device in broadband data transmission, belonging to the technical field of broadband digital communication. The compensation processing provided by the invention is carried out on the basis of analog-to-digital conversion, digital frequency conversion, filtering and synchronization of input signals, the compensation coefficient calculation is carried out by utilizing the training sequence in the data frame transmitted by a channel, and then the compensation processing is completed by sliding multiplication and accumulation operation, so that the countervailing capability of a broadband data transmission system to frequency selective fading is obviously improved. The invention has the advantages of low power consumption, high resource utilization rate, high operation speed, easy expansion, parallel processing and the like, and can be widely applied to broadband digital receivers such as radars, communication, measurement and control and the like.)

1. A method for frequency selective fading compensation in wideband data transmission, comprising the steps of:

(1) performing analog-to-digital conversion on the received analog signals, and performing digital frequency conversion and filtering processing on the data after the analog-to-digital conversion to obtain in-phase baseband signals and quadrature baseband signals;

(2) respectively and sequentially carrying out symbol synchronization, carrier synchronization and frame synchronization on the two paths of baseband signals to obtain a synchronous data frame;

(3) and (3) carrying out frequency selective fading compensation on the synchronous data frame obtained in the step (2), wherein the specific method comprises the following steps:

(301) extracting a plurality of received training sequences from the synchronous data frame, carrying out average filtering processing, and simultaneously calculating a cyclic shift matrix of a known training sequence;

(302) calculating a transfer function of the training sequence according to a cyclic shift matrix of the known training sequence and the received training sequence after average filtering;

(303) calculating a frequency selective fading compensation coefficient according to the transfer function;

(304) according to the processing time delay, carrying out time delay processing on the current synchronous data frame;

(305) and compensating the frequency selective fading of the delayed synchronous data frame according to the frequency selective fading compensation coefficient.

2. The method of claim 1, wherein the step (301) of receiving the training sequence comprises: r is_sq0，r_sq1，r_sq2，r_sq3And removing the head and the tail, wherein the average filtered receiving training sequence is as follows: r is_sq＝(r_sq1+r_sq2)/2。

3. The method for compensating for frequency selective fading in broadband data transmission according to claim 2, wherein the cyclic shift matrix in step (301) is:

in the formula, t_sqFor a known training sequence, N is the length of the received training sequence, and L is a positive integer no greater than N.

4. A method for frequency selective fading compensation in broadband data transmission according to claim 3, wherein the transfer function in step (302) is:

C_sq＝{sum[(1-SQ_A*2)*(1-1i*1)*r_sq]+32*[(1-SQ_A*2)*(1-1i*1)*r_sq]}/2048

in which sum represents the sum, C_sqThe length is L for the transfer function.

5. The method as claimed in claim 4, wherein the frequency selective fading compensation coefficient in the step (303) is:

wherein the content of the first and second substances,

6. the method for compensating for frequency selective fading in broadband data transmission according to claim 5, wherein the frequency selective fading compensation result in step (305) is:

wherein, x (k) is a delayed synchronous data frame with a length of M.

7. A frequency selective fading compensation device in broadband data transmission is characterized by comprising an analog-to-digital conversion module (1), a synchronization module (2) and a frequency selective fading compensation module (3);

the analog-to-digital conversion module (1) is used for performing analog-to-digital conversion on the received analog signals, performing digital frequency conversion and filtering processing on the data after the analog-to-digital conversion to obtain in-phase and orthogonal baseband signals, and transmitting the in-phase and orthogonal baseband signals to the synchronization module (2);

the synchronization module (2) is used for respectively and sequentially carrying out symbol synchronization, carrier synchronization and frame synchronization on the two paths of baseband signals to obtain a synchronous data frame, and transmitting the synchronous data frame to the frequency selective fading compensation module (3);

the frequency selective fading compensation module (3) is used for carrying out frequency selective fading compensation on the synchronous data frame;

the frequency selective fading compensation module (3) comprises a received training sequence average filtering calculation module (301), a cyclic shift matrix calculation module (302), a transfer function calculation module (303), a compensation coefficient calculation module (304), a data time delay module (305) and a frequency selective fading compensation module (306);

the receiving training sequence average filtering calculation module (301) is used for extracting a plurality of receiving training sequences from the synchronous data frame, carrying out average filtering processing and transmitting the receiving training sequences after average filtering to the transfer function calculation module (303);

the cyclic shift matrix calculation module (302) is used for calculating a cyclic shift matrix of a known training sequence and transmitting the cyclic shift matrix to the transfer function calculation module (303);

the transfer function calculation module (303) is used for calculating a transfer function of the training sequence according to the cyclic shift matrix of the known training sequence and the average filtered received training sequence, and transmitting the transfer function to the compensation coefficient calculation module (304);

the compensation coefficient calculation module (304) is used for calculating a frequency selective fading compensation coefficient according to the transfer function and transmitting the frequency selective fading compensation coefficient to the frequency selective fading compensation module (306);

the data delay module (305) is used for carrying out delay processing on the current synchronous data frame according to the processing delay and transmitting the delayed synchronous data frame to the frequency selective fading compensation module (306);

and the frequency selective fading compensation module (306) is used for compensating the frequency selective fading of the delayed synchronous data frame according to the frequency selective fading compensation coefficient.

Technical Field

The present invention relates to the field of wideband digital communication technologies, and in particular, to a frequency selective fading compensation method and apparatus in wideband data transmission.

Background

At present, due to the rapid development of the wireless broadband digital communication technology, the experience degree of people is greatly improved, and the rapid development of social economy is met. However, in broadband data transmission, the signal bandwidth is much larger than the coherence bandwidth of the channel, so the frequency selective fading is severe, which leads to the increase of the system error rate and even the system cannot work. How to compensate for frequency selective fading in broadband data transmission is attracting more and more attention.

To solve this problem, a compensation method based on maximum likelihood, a compensation method based on adaptive linear compensation, and a compensation method based on frequency domain division have been proposed. With the improvement of the data transmission rate, the method has the problems of high operation resource consumption, low convergence speed, low effectiveness, no parallel high-speed realization and the like.

Disclosure of Invention

The technical problem to be solved by the present invention is to solve the above problems in the background art, and to provide a frequency selectivity compensation method and device in broadband data transmission, which have the characteristics of fast convergence rate, low cost, and suitability for parallel high-speed implementation, and can be used in a broadband data transmission receiver.

In order to achieve the purpose, the invention adopts the technical scheme that:

a method for frequency selective fading compensation in broadband data transmission, comprising the steps of:

(1) performing analog-to-digital conversion on the received analog signals, and performing digital frequency conversion and filtering processing on the data after the analog-to-digital conversion to obtain in-phase baseband signals and quadrature baseband signals;

(2) respectively and sequentially carrying out symbol synchronization, carrier synchronization and frame synchronization on the two paths of baseband signals to obtain a synchronous data frame;

(3) and (3) carrying out frequency selective fading compensation on the synchronous data frame obtained in the step (2), wherein the specific method comprises the following steps:

(301) extracting a plurality of received training sequences from the synchronous data frame, carrying out average filtering processing, and simultaneously calculating a cyclic shift matrix of a known training sequence;

(302) calculating a transfer function of the training sequence according to a cyclic shift matrix of the known training sequence and the received training sequence after average filtering;

(303) calculating a frequency selective fading compensation coefficient according to the transfer function;

(304) according to the processing time delay, carrying out time delay processing on the current synchronous data frame;

(305) and compensating the frequency selective fading of the delayed synchronous data frame according to the frequency selective fading compensation coefficient.

Further, the step (301) of receiving the training sequence includes: r is_sq0，r_sq1，r_sq2，r_sq3And removing the head and the tail, wherein the average filtered receiving training sequence is as follows: r is_sq＝(r_sq1+r_sq2)/2。

Further, the cyclic shift matrix in step (301) is:

wherein, t_sqFor a known training sequence, N is the length of the received training sequence, and L is a positive integer no greater than N.

Further, the transfer function in the step (302) is:

C_sq＝{sum[(1-SQ_A*2)*(1-1i*1)*r_sq]+32*[(1-SQ_A*2)*(1-1i*1)*r_sq]}/2048

where sum represents the sum, C_sqThe length is L for the transfer function.

Further, the frequency selective fading compensation coefficient in step (303) is:

wherein the content of the first and second substances,

further, the frequency selective fading compensation result in the step (305) is:

wherein, x (k) is a delayed synchronous data frame with a length of M.

A frequency selective fading compensation device in broadband data transmission comprises an analog-to-digital conversion module (1), a synchronization module (2) and a frequency selective fading compensation module (3);

the analog-to-digital conversion module (1) is used for performing analog-to-digital conversion on the received analog signals, performing digital frequency conversion and filtering processing on the data after the analog-to-digital conversion to obtain in-phase and orthogonal baseband signals, and transmitting the in-phase and orthogonal baseband signals to the synchronization module (2);

the synchronization module (2) is used for respectively and sequentially carrying out symbol synchronization, carrier synchronization and frame synchronization on the two paths of baseband signals to obtain a synchronous data frame, and transmitting the synchronous data frame to the frequency selective fading compensation module (3);

the frequency selective fading compensation module (3) is used for carrying out frequency selective fading compensation on the synchronous data frame;

the frequency selective fading compensation module (3) comprises a received training sequence average filtering calculation module (301), a cyclic shift matrix calculation module (302), a transfer function calculation module (303), a compensation coefficient calculation module (304), a data time delay module (305) and a frequency selective fading compensation module (306);

the receiving training sequence average filtering calculation module (301) is used for extracting a plurality of receiving training sequences from the synchronous data frame, carrying out average filtering processing and transmitting the receiving training sequences after average filtering to the transfer function calculation module (303);

the cyclic shift matrix calculation module (302) is used for calculating a cyclic shift matrix of a known training sequence and transmitting the cyclic shift matrix to the transfer function calculation module (303);

the transfer function calculation module (303) is used for calculating a transfer function of the training sequence according to the cyclic shift matrix of the known training sequence and the average filtered received training sequence, and transmitting the transfer function to the compensation coefficient calculation module (304);

the compensation coefficient calculation module (304) is used for calculating a frequency selective fading compensation coefficient according to the transfer function and transmitting the frequency selective fading compensation coefficient to the frequency selective fading compensation module (306);

the data delay module (305) is used for carrying out delay processing on the current synchronous data frame according to the processing delay and transmitting the delayed synchronous data frame to the frequency selective fading compensation module (306);

and the frequency selective fading compensation module (306) is used for compensating the frequency selective fading of the delayed synchronous data frame according to the frequency selective fading compensation coefficient.

Compared with the background technology, the invention has the following advantages:

1. compared with the traditional maximum likelihood method and frequency domain division method, the method has the advantage of low resource consumption.

2. Compared with the traditional adaptive linear compensation method, the method has the advantages of simple operation, high convergence rate and high timeliness, and is particularly suitable for broadband high-speed data transmission.

Drawings

Fig. 1 is a schematic block diagram of a system for frequency selective fading compensation according to an embodiment of the present invention, in which an input signal is an analog signal received by a broadband data transmission system.

Fig. 2 is a schematic block diagram of the frequency selective fading compensation module in fig. 1 according to an embodiment of the present invention.

In the figure: 1. the device comprises an analog-to-digital conversion module, a synchronization module, a frequency selective fading compensation module, a receiving training sequence average filtering calculation module 301, a cyclic shift matrix calculation module 302, a transfer function calculation module 303, a compensation coefficient calculation module 304, a data delay module 305, a frequency selective fading compensation module 306.

Detailed Description

The technical solution of the present invention is further explained with reference to the accompanying drawings and specific embodiments.

A method of frequency selective fading compensation in broadband data transmission, comprising the steps of:

(1) performing analog-to-digital conversion on the received analog signals, and performing digital frequency conversion and filtering processing on the data after the analog-to-digital conversion to obtain in-phase baseband signals and quadrature baseband signals;

(2) respectively and sequentially carrying out symbol synchronization, carrier synchronization and frame synchronization on the two paths of baseband signals to obtain a synchronous data frame;

(3) and (3) carrying out frequency selective fading compensation on the synchronous data frame obtained in the step (2), wherein the specific method comprises the following steps:

(301) extracting a plurality of received training sequences from the synchronous data frame, carrying out average filtering processing, and simultaneously calculating a cyclic shift matrix of a known training sequence;

(302) calculating a transfer function of the training sequence according to a cyclic shift matrix of the known training sequence and the received training sequence after average filtering;

(303) calculating a frequency selective fading compensation coefficient according to the transfer function;

(304) according to the processing time delay, carrying out time delay processing on the current synchronous data frame;

(305) and compensating the frequency selective fading of the delayed synchronous data frame according to the frequency selective fading compensation coefficient.

The above method can be implemented by the system shown in fig. 1 and 2:

a receiving signal of the broadband data transmission system is firstly input into an analog-to-digital conversion module 1, the analog-to-digital conversion module 1 carries out large-dynamic high-speed high-precision sampling on the input analog signal to obtain a sampling signal, and digital frequency conversion and filtering processing are carried out on the sampling signal to obtain in-phase and orthogonal baseband signals. Then, the synchronization module 2 performs symbol synchronization, carrier synchronization, and frame synchronization on the baseband signal, and outputs a synchronization data frame. Finally, the frequency selective fading compensation module 3 performs frequency selective fading compensation on the synchronous data frame, and the specific method is as follows:

the received training sequence average filtering calculation module 301 performs average filtering on the received training sequence; receiving the training sequence includes: r is_sq0，r_sq1，r_sq2，r_sq3And removing the head and the tail, wherein the average filtered receiving training sequence is as follows: r is_sq＝(r_sq1+r_sq2)/2，r_sqHas a length of N, wherein r_sq1，r_sq2Receiving training sequences for the received 2 nd and 3 rd;

the cyclic shift calculation module 302 calculates a cyclic shift matrix of the training sequence according to the known training sequence; the cyclic shift matrix is:

wherein, t_sqIs a known training sequence, N is the length of the training sequence, and L is a positive integer not greater than N;

the transfer function calculation module 303 constructs a transfer function of the current training sequence according to the received average filtering training sequence and the cyclic shift matrix; the transfer function is:

C_sq＝{sum[(1-SQ_A*2)*(1-1i*1)*r_sq]+32*[(1-SQ_A*2)*(1-1i*1)*r_sq]}/2048

where sum represents the sum, 1i represents the imaginary part of the complex number, C_sqIs a transfer function, with a length L;

the compensation coefficient calculation module 304 solves the compensation coefficient of the frequency selective fading at the current moment according to the transfer function; the frequency selective fading compensation coefficient is as follows:

wherein the content of the first and second substances,

j represents a complex number.

The data delay module 305 performs delay processing on the current synchronous data frame according to the data processing delay;

the frequency selective fading compensation module 306 completes the frequency selective compensation of the delayed synchronous data frame according to the frequency selective fading compensation coefficient; the frequency selective fading compensation result is:

wherein, x (k) is a delayed synchronous data frame with a length of M.

In summary, the method of the present invention is performed on the basis of analog-to-digital conversion, digital frequency conversion, filtering and synchronization of input signals, and performs compensation coefficient calculation by using training sequences in data frames transmitted by a channel, and then completes compensation processing through sliding multiplication and accumulation operation, thereby significantly improving the countervailing ability of a broadband data transmission system to frequency selective fading. The invention has the advantages of low power consumption, high resource utilization rate, high operation speed, easy expansion, parallel processing and the like, and can be widely applied to broadband digital receivers such as radars, communication, measurement and control and the like.