CN113364558A

CN113364558A - Coding method based on own communication protocol WIoTA

Info

Publication number: CN113364558A
Application number: CN202110626737.4A
Authority: CN
Inventors: 杨飞云; 龙定彪; 王浩; 徐顺来; 蒲施桦; 曾雅琼; 朱佳明; 简悦; 周凤; 李晟
Original assignee: Chongqing Yuxin Micro Information Technology Co ltd; Chongqing Academy of Animal Sciences
Current assignee: Chongqing Yuxin Micro Information Technology Co ltd; Chongqing Academy of Animal Sciences
Priority date: 2021-06-04
Filing date: 2021-06-04
Publication date: 2021-09-07

Abstract

The invention discloses a coding method based on a WIoTA (wireless internet protocol for Ethernet) of an own communication protocol, which comprises the following coding steps: sequentially converting the bit stream to be coded into a non-binary group, sequentially writing the non-binary group into a shift register, and filling an initial value of the shift register into a value of the non-binary group arranged at the tail end; each time of shifting, firstly extracting a plurality of taps, calculating a first group of check groups by using a non-binary coding algorithm, and then repeating the following operations until the check groups with the preset number of groups are obtained: interleaving the tap values according to bits, and calculating a corresponding check group by using a non-binary coding algorithm; arranging all non-binary groups and all check groups in sequence before the non-binary groups obtained by converting the bit stream to generate a coded bit stream; the decoding step comprises: and processing the coded bit stream by using a non-binary decoding algorithm, and then performing local iterative decoding, wherein in the iterative process, the extended attribute information is exchanged between each iteration through de-interleaving. The invention can greatly improve the Eb/N0 system.

Description

Coding method based on own communication protocol WIoTA

Technical Field

The invention relates to the field of Internet of things, in particular to a coding method based on a wireless internet protocol (WIoTA).

Background

The existing wireless communication systems, such as the systems of LTE, WiFi, Lora, etc., all use long codes, are used in the environment with higher code rate, and for the low code rate scene, the system Eb/N0 is not good.

Disclosure of Invention

The invention aims to: in view of the existing problems, a method for improving the communication signal-to-noise ratio (Eb/N0) of a low code rate wireless communication system is provided.

The technical scheme adopted by the invention is as follows:

an encoding method based on the own communication protocol WIoTA, a communication channel comprises a data channel and a common control channel, the data channel comprises an encoding step and a decoding step, and the encoding step of the data channel comprises the following steps:

sequentially transforming the bit stream to be encoded into non-binary groups, each non-binary group containing a bit stream of a predetermined length;

sequentially writing the non-binary groups into a shift register, and filling an initial value of the shift register with a value of the non-binary group arranged at the tail end; each time of shifting, firstly extracting a plurality of taps, calculating a first group of check groups by using a non-binary coding algorithm, and then repeatedly executing the following operations until the check groups with the preset number of groups are obtained: interleaving the tap values according to bits, and calculating a corresponding check group by using a non-binary coding algorithm;

and arranging all the non-binary groups and all the check groups in sequence before the non-binary groups obtained by converting the bit stream to generate the coded bit stream.

Further, the values of the pair of taps are bit-interleaved, including:

and (3) inquiring a bit address from a preset local interleaver for each bit of the tap values in the sequence of the tap values, and interleaving.

Further, the non-binary encoding algorithm is a non-binary parity check algorithm.

Further, the decoding step of the data channel comprises:

and processing the coded bit stream by using a non-binary decoding algorithm, and then performing local iterative decoding, wherein in the iterative process, the extended attribute information is exchanged between each iteration through de-interleaving.

Further, the local iterative decoding is to perform iterative operation between check groups in sequence.

Further, the non-binary decoding algorithm is a grid minimum sum algorithm.

Further, the common control channel includes an encoding step of:

judging whether the length of the bit stream to be coded reaches a preset length, wherein the preset length is determined by the number of the extracted taps and the length of the non-binary group; if not, a multi-interleaving encoder is used for encoding the data to be encoded, and the bit bits with insufficient length are filled with zeros for supplementation; if yes, the bit stream to be coded is coded by using the same method as the coding step of the data channel. In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. the coding method has sufficient flexibility and can provide excellent performance for the scenes of high code rate and ultralow code rate (1/16-1/30).

2. The invention is based on the non-binary encoder structure, so that the system can work well under high code rate, the code rate of the encoder can be designed to be very low, and the Eb/N0 performance can be greatly improved.

3. In the encoding flow and the decoding flow, the interleaver can be designed to effectively reduce the complexity of system operation.

Drawings

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

fig. 1 is a diagram of an NB-LICC encoder configuration.

Fig. 2 is a schematic diagram of a bitstream after conversion into non-binary groups.

FIG. 3 is a check set generation flow diagram.

Fig. 4 is a schematic diagram of a bit mapping relationship.

Fig. 5 is a Tanner graph of advanced check nodes.

Fig. 6 is a local iterative decoding flow chart.

Fig. 7 is an advanced check node decoding flow diagram.

FIG. 8 is a graph of BER for NB-LICC lower bit rate concatenation Hadmard.

Detailed Description

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.

Any feature disclosed in this specification (including any accompanying claims, abstract) may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

A coding method based on the own communication protocol WIoTA, wherein a communication channel comprises a data channel and a common control channel, and the method comprises a data channel coding method and a common control channel coding method. The data channel coding method comprises a coding step and a decoding step, wherein:

the encoding step includes:

1) the bit stream is sequentially transformed into non-binary groups, each non-binary group containing bits of a predetermined length.

A basic NB-LICC (Non-binary local interleaved convolutional code, NB-LICC, Non-binary inner interleaved convolutional code) encoder structure is as shown in fig. 1, this step implements conversion of bits (bits) into Non-binary groups (Non-binary groups), the length of one Non-binary group is predetermined, that is, a predetermined bit (n _ bits _ per _ group, n is a positive integer) can be included, and the bit stream is sequentially divided into a plurality of binary groups according to the order of bits in the bit stream and the predetermined length. Fig. 2 shows an example of 4bits (4bits) as a non-binary group.

2) And sequentially writing the converted non-binary groups into the shift register by taking the non-binary groups as units.

Similar to a tail-biting convolutional code (TBCC), the initial values of the shift registers are filled with the values of the last several non-binary groups. Each time of shifting, the values (n _ tap) of several taps (tap) are extracted to calculate the check information. The number of taps and the calculated coefficients (h0, h1 …), which are also represented in non-binary (non-binary), are determined by the configuration parameters NB-LICC-Poly.

As shown in fig. 3, taking the extraction of 4 taps as an example, the values of the extracted 4 taps are ga, gb, gc, and gd, and a first group of check groups are obtained by a non-binary parity check (parity check) operation: p _ g 0. Adopting a local interleaver to interleave ga, gb, gc and gd according to bits to generate new 4 non-binary groups, and obtaining a second group of check groups through non-binary parity check operation: p _ g 1. By analogy, all check groups can be obtained by repeating interleaving and parity check operation. In the figure, I0 and I1 … Ik-1 indicate that a new non-binary group combination is obtained after tap interleaving. If the number of the check groups is K, the code rate of the coding method is 1/(1+ K).

3) And (4) arranging the non-binary groups obtained by converting the bit stream and all check groups obtained by operation in sequence before the non-binary groups obtained by converting the bit stream to generate the final coded bit stream.

The NB-LICC encoder is constructed by the above encoding process. In the above coding process, the interleaving process is the key for determining the channel coding. The general interleaver performs global interleaving (all information bits are interleaved uniformly), which is very disadvantageous to implementation and has high complexity. The embodiment provides a local interleaving scheme to greatly reduce the complexity of coding and decoding, improve the constrained depth by times, and improve the performance of the encoder.

In some embodiments, taking the example of 4 taps being extracted and the length of the non-binary group being 4bits, the design of the 20 interleavers is shown in the following table:

interleaver index	Bit address mapping
		0	7 1 2 12 0 5 9 8 14 13 15 4 10 11 3 6
1	6 5 11 13 2 9 7 14 10 4 3 15 0 12 1 8
		2	3 4 12 9 13 7 5 11 15 2 14 8 6 0 10 1
3	11 10 15 5 0 8 12 3 9 2 7 6 13 1 4 14
		4	2 15 4 8 10 6 3 14 1 7 0 9 11 12 13 5
5	10 6 14 8 2 0 15 7 4 11 12 3 13 1 9 5
		6	7 11 6 4 0 5 14 2 15 10 9 13 1 12 8 3
7	13 14 9 4 5 15 10 2 11 1 3 8 0 12 6 7
		8	9 15 7 2 8 10 5 3 12 14 11 4 1 0 6 13
9	4 8 14 12 9 10 2 1 15 0 11 13 7 5 6 3
		10	8 7 5 11 0 10 13 14 6 2 9 1 15 4 3 12
11	5 14 12 15 7 2 3 11 6 10 1 13 9 0 4 8
		12	14 1 15 5 12 11 7 0 9 6 4 10 3 2 13 8
13	12 4 15 14 0 10 1 5 7 11 6 9 8 3 2 13
		14	15 7 9 2 8 4 12 0 10 5 14 3 6 13 11 1
15	0 7 14 5 8 4 10 13 2 15 12 6 11 1 9 3
		16	2 12 5 8 10 11 7 9 14 4 6 15 0 3 1 13
17	5 9 0 1 2 15 4 3 7 8 14 13 10 6 11 12
		18	9 7 5 12 15 2 11 3 6 1 13 8 14 0 4 10
19	3 4 15 11 1 0 14 7 13 6 5 12 9 8 2 10

The interleaving process is interleaving by taking bit as a unit, the 4 taps and the 4 non-binary groups are arranged, the length of each non-binary group is 4bits, the non-binary group corresponds to 16bits, and bit addresses after 16bit interleaving are obtained by inquiring according to the interleaver in the table above.

Take the bit stream of row 0 for local interleaving as an example. The table interleaver is queried, and the obtained bit address mapping relation is: 7,1,2, 12,0,5,9,8, 14, 13, 15,4, 10, 11,3,6. The bit mapping method shown in fig. 4 is used to interleave the interleaving pattern, and other rows are locally interleaved by similar table lookup and bit mapping methods.

The decoding step comprises:

and processing the coded bit stream by using a non-binary check decoding algorithm, and then performing local iterative decoding.

The NB-LICC is different from general channel coding, and a decoder needs a special structure, similar to a decoding algorithm of Belif-propagation (bp), in this embodiment, an advanced check node (advanced check node) is designed, and the advanced check node needs local iterative decoding in addition to using a non-binary check decoding algorithm. Fig. 5 shows a Tanner graph of advanced check nodes. The flow of local iterative decoding is shown in fig. 6.

In fig. 5, the decoding flow of each advanced check node is as shown in fig. 7, iterative operations are performed inside one advanced check node, that is, between different check groups, and extended attribute (ext-info) information is exchanged between each iterative operation, and the process of exchanging extended attribute information needs to be performed with interleaving, and is completed by using the above-designed local interleaver. In the decoding flow shown in fig. 7, a non-binary parity check node (non-binary parity check node) may employ a non-binary decoding algorithm such as trellis min-sum (trellis min-sum).

Experiments prove that when the bit of the information data is 192 and the code rate is 1/83, the NB-LICC is shown in FIG. 8 as a BER curve of a lower code rate cascade Hadmard (Ping Li etc. "Decoding Technique of coordinated hadamard codes and bits performance"), and as can be seen from FIG. 8, the NB-LICC obtains a performance gain of 0.7dB, avoids complex interleaving processing, and greatly reduces the complexity of encoding and Decoding.

The common control channel coding method comprises the following steps:

and (2) encoding data to be encoded by adopting an NB-LICC encoder, wherein if the number of bits of the data to be encoded is less than or equal to n _ bits _ per _ group _ n _ tap, an internal multi-interleaver encoder is directly adopted, an enable (enabler) is not adopted as a register, and bits with insufficient length are filled with zero to 16 bits. If the number of bits of the data to be encoded is large (more than n _ bits _ per _ group _ n _ tap), the same encoding process as the data channel is directly adopted.

NB-LICC _ MIN _ CODING _ RATE defines the minimum code RATE supported by the system and also defines the number of interleavers which can be used by NB-LICC. When N _ PDU _ bits/N _ RE < NB-LICC _ MIN _ CODING _ RATE (N _ PDU _ bits represents the number of length of protocol data unit, N _ RE represents the number of available resource elements prime), a repetition (repetition) process is also needed to repeat the CODING method described in the first segment of common control channel until N _ PDU _ bits/N _ RE > -NB-LICC _ MIN _ CODING _ RATE fills all available Resource Elements (RE). PDU is protocol data unit, PDU bit is protocol data unit length, and public control channel's protocol data unit length is less.

N _ interleaver defines the number of interleavers used, and needs to satisfy 1/(1+ N _ interleaver) > NB-LICC _ MIN _ CODING _ RATE.

The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.

Claims

1. An encoding method based on the own communication protocol WIoTA, wherein a communication channel comprises a data channel and a common control channel, the data channel comprises an encoding step and a decoding step, and the encoding step of the data channel comprises the following steps:

2. The autonomous communication protocol WIoTA-based encoding method as claimed in claim 1, wherein said interleaving of the values of the taps in bits comprises:

3. The WIoTA-based encoding method of claim 1 wherein the non-binary encoding algorithm is a non-binary parity check algorithm.

4. The WIoTA-based encoding method as claimed in claim 1, wherein the decoding step of the data channel comprises:

5. The WIoTA-based encoding method according to claim 4, wherein said local iterative decoding is an iterative operation performed between check groups in sequence.

6. The WIoTA-based encoding method according to claim 4 or 5, wherein said non-binary decoding algorithm is a trellis-min-sum algorithm.

7. The wireless-over-the-air (WIoTA) -based encoding method as claimed in claim 1, wherein the common control channel includes the encoding steps of:

judging whether the length of the bit stream to be coded reaches a preset length, wherein the preset length is determined by the number of the extracted taps and the length of the non-binary group; if not, a multi-interleaving encoder is used for encoding the data to be encoded, and the bit bits with insufficient length are filled with zeros for supplementation; if yes, the bit stream to be coded is coded by using the same method as the coding step of the data channel.