CN115174000A - EDD-CCM-based adaptive adjustment method for rate under fading channel - Google Patents
EDD-CCM-based adaptive adjustment method for rate under fading channel Download PDFInfo
- Publication number
- CN115174000A CN115174000A CN202210836595.9A CN202210836595A CN115174000A CN 115174000 A CN115174000 A CN 115174000A CN 202210836595 A CN202210836595 A CN 202210836595A CN 115174000 A CN115174000 A CN 115174000A
- Authority
- CN
- China
- Prior art keywords
- symbol
- ccm
- decoding
- symbols
- edd
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0078—Avoidance of errors by organising the transmitted data in a format specifically designed to deal with errors, e.g. location
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2668—Details of algorithms
- H04L27/2681—Details of algorithms characterised by constraints
- H04L27/2688—Resistance to perturbation, e.g. noise, interference or fading
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Detection And Prevention Of Errors In Transmission (AREA)
Abstract
The invention discloses a rate self-adaptive adjusting method under a fading channel based on EDD-CCM, which improves a sending symbol and a decoding method of the CCM method, firstly converts an original RP symbol into a low-order symbol at a sending end for sending and adding an error detection code, then converts the low-order symbol into the RP symbol at a receiving end, simultaneously deletes the wrong RP symbol by using the error detection code, and only carries out subsequent decoding by using the checked RP symbol. Therefore, the code modulation method which has lower interruption probability under the conditions of a fading channel and low signal-to-noise ratio and has a certain rate self-adaptive adjustment capability is obtained, and high-reliability transmission of certain key instruction information under the condition of a severe channel is ensured.
Description
Technical Field
The invention belongs to the technical field of wireless communication, and particularly relates to a rate self-adaptive adjusting method under a fading channel based on EDD-CCM.
Background
In the field of wireless communication, fading refers to a phenomenon in which the amplitude of a received signal changes randomly due to channel variations, i.e., signal fading. The channel that causes the signal to fade is referred to as a fading channel. The bit symbol mapping mode that a certain weight set is used for weighting and summing to generate transmission symbols in the CCM method basically belongs to high-order modulation with the order of more than 8, although the use of the high-order modulation enables the CCM method to carry out self-adaptive adjustment in a large rate range without rapid saturation, the use of the high-order modulation also enables the anti-noise capacity of the symbols of the CCM in the channel transmission process to be weakened, the number of error symbols of a receiving end is increased in the case of low signal-to-noise ratio, and therefore the decoding success rate is reduced. In particular, under high dynamic channel conditions, a symbol transmission channel inevitably suffers from multipath fading, and the error rate of high-order modulation under a fading channel is severely increased compared with that of a gaussian white noise channel. Therefore, the existing CCM method will cause the performance of adaptive rate adjustment to be degraded due to the large error of most received RP symbols under the fading channel condition, and even cause the communication to be completely interrupted.
Similarly, according to the RPC-BP decoding process, it can be known that, while receiving the RP symbol, the RPC-BP decoding method needs to estimate the noise probability distribution function of the received signal, so as to perform decoding estimation, i.e. step 2 in the steps of the RPC-BP decoding method. Decoding with the joint noise distribution probability function can certainly obtain better decoding performance, but under a fading channel, more calculation amount is inevitably needed to obtain accurate and real-time estimation of the fast time-varying noise probability distribution function. In addition, inaccurate noise distribution estimation also increases the number of iterations required for successful decoding.
Disclosure of Invention
In order to solve the technical problem, the invention provides a rate self-adaptive adjusting method under a fading channel based on EDD-CCM, which improves a sending symbol and a decoding method of the CCM method. Therefore, the code modulation method which has lower interruption probability under the conditions of a fading channel and low signal-to-noise ratio and has a certain rate self-adaptive adjustment capability is obtained, and high-reliability transmission of certain key instruction information under the condition of a severe channel is ensured.
In order to achieve the technical purpose, the invention is realized by the following technical scheme:
a method for adaptively adjusting the rate under a fading channel based on EDD-CCM comprises the following steps:
s1: at a sending end, RPC is used for modulating information source bit information to generate an RP symbol, then the RP symbol is converted into corresponding signed binary information, CRC error detection check information is added, finally QPSK modulation with better spectrum efficiency and anti-noise performance is used for re-completing bit-symbol mapping, and a multi-carrier signal to be sent is generated through IFFT;
s2: after the receiving end completes QPSK demodulation in an opposite process, firstly, error detection check is carried out on binary bit information corresponding to the RP symbols, the RP symbols which fail to be checked are deleted, RPC-BP decoding is carried out on a plurality of discontinuous RP symbols which are successfully checked, and finally, sent information source bit information is obtained;
s3: for the transmission rate of the EDD-CCM method, the transmission rate is related to the value range of the RP symbol and the length of the CRC check bit; defining the length of signed binary representation corresponding to the maximum value of RP symbols generated under a certain weight set to be L RP_bin CRC check bit length of L CRC The transmission rate of the EDD-CCM method can be expressed as
Preferably, in the step S2, in order to ensure a low error detection probability, that is, a symbol that is successfully checked is a completely correct symbol, a CRC error detection code with a good error detection performance is used;
preferably, the CRC check bit length needs to be selected in a compromise manner according to performance requirements;
preferably, in S2, before performing RPC-BP decoding on a plurality of restored non-consecutive integer value RP symbols, rows of the generated matrix G need to be correspondingly deleted according to positions of the deleted RP symbols, that is, rows corresponding to RP symbols failed in detection in the G matrix need to be correspondingly deleted, then the RPC-BP decoding is performed on the G matrix after processing, and corresponding calculation is performed in the decoding process according to equations (1) and (2):
preferably, the specific processing flow of the receiving end in S2 is: grouping QPSK demodulated bit information and CRC check information according to a pre-conversion principle at a receiving end, wherein each group represents an RP symbol; then performing CRC (cyclic redundancy check) and RP (redundancy protocol) symbol restoration on each group of bits, and deleting and marking the position of the RP symbol failed in the verification; because each row of the generating matrix correspondingly generates an RP symbol, the rows of the decoding matrix (namely the generating matrix) are correspondingly deleted according to the marked position of the error symbol before the RP symbol is decoded after the error symbol is deleted; finally, the information source bit information b can be recovered by carrying out RPC-BP decoding by the restored and successfully verified integer value RP symbol 1 ,b 2 ,b 3 ,...b M 。
The invention has the beneficial effects that:
according to the invention, firstly, a high-order RPC symbol is converted into a low-order QPSK symbol in S1, so that the anti-noise performance of the symbol is improved, and compared with a CCM method, the method is more suitable for fading channels; in S2, firstly, CRC (cyclic redundancy check) information is used for carrying out error detection and deletion on the received symbols, and then decoding is carried out based on integer symbols, compared with an RPC-BP (remote procedure call-back) decoding method, the noise probability distribution function of a receiving end does not need to be calculated, so that not only is the calculation complexity reduced, but also the decoding success rate under the condition of low signal-to-noise ratio is improved; finally, in S3, the transmission rate of the invention can be controlled and adjusted through the number of the initial sending symbols, the sending step, the sending times and the CRC check bit length.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a block diagram of the EDD-CCM method based rate adjustment flow of the present invention;
FIG. 2 is a schematic diagram of the EDD-CCM method of the present invention.
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.
Example 1
A method for adaptively adjusting the rate under a fading channel based on EDD-CCM comprises the following steps:
s1: at a sending end, RPC is used for modulating information source bit information to generate an RP symbol, then the RP symbol is converted into corresponding signed binary information, CRC error detection check information is added, finally QPSK modulation with better spectrum efficiency and anti-noise performance is used for re-completing bit-symbol mapping, and a multi-carrier signal to be sent is generated through IFFT;
s2: after the receiving end completes QPSK demodulation in an opposite process, firstly, error detection check is carried out on binary bit information corresponding to the RP symbols, the RP symbols which fail to be checked are deleted, RPC-BP decoding is carried out on a plurality of discontinuous RP symbols which are successfully checked, and finally, sent information source bit information is obtained;
s3: for the transmission rate of the EDD-CCM method, the value range of the EDD-CCM method is related to the value range of the RP symbol and the length of the CRC check bitRelated to; defining the length of signed binary representation corresponding to the maximum value of RP symbols generated under a certain weight set to be L RP_bin CRC check bit length of L CRC The transmission rate of the EDD-CCM method can be expressed as
Preferably, in step S2, in order to ensure a low error detection probability, that is, a symbol that is successfully checked is a completely correct symbol, a CRC error detection code with a good error detection performance is used;
preferably, the CRC check bit length needs to be selected in a compromise manner according to performance requirements;
preferably, in S2, before performing RPC-BP decoding on a plurality of restored non-consecutive integer value RP symbols, rows of the generation matrix G need to be correspondingly deleted according to positions of the deleted RP symbols, that is, rows corresponding to RP symbols that fail to be detected in the G matrix are correspondingly deleted, then the RPC-BP decoding is performed on the G matrix after processing, and corresponding calculation is performed in the decoding process according to equations (1) and (2):
preferably, the specific processing flow of the receiving end in S2 is: grouping QPSK demodulated bit information and CRC check information according to a predetermined conversion principle at a receiving end, wherein each group represents an RP symbol; then, performing CRC (cyclic redundancy check) and RP (reverse protocol) symbol reduction on each group of bits, and deleting and marking the RP symbol position failed in verification; because each row of the generating matrix correspondingly generates an RP symbol, the rows of the decoding matrix (namely the generating matrix) are correspondingly deleted according to the marked position of the error symbol before the RP symbol is decoded after the error symbol is deleted; finally, by reduction and check toThe integral value RP symbol of the work can recover the information source bit information b by RPC-BP decoding 1 ,b 2 ,b 3 ,...b M 。
In the description herein, references to the description of "one embodiment," "an example," "a specific example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best understand the invention for and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims (5)
1. A method for adaptively adjusting the rate under a fading channel based on EDD-CCM (enhanced digital-code communication-continuous mode), which is characterized by comprising the following steps:
s1: at a sending end, RPC is used for modulating information source bit information to generate an RP symbol, then the RP symbol is converted into corresponding signed binary information, CRC error detection check information is added, finally QPSK modulation with better spectrum efficiency and anti-noise performance is used for re-completing bit-symbol mapping, and a multi-carrier signal to be sent is generated through IFFT;
s2: after the receiving end completes QPSK demodulation in a reverse process, error detection and verification are firstly carried out on binary bit information corresponding to the RP symbols, the RP symbols which fail to be verified are deleted, RPC-BP decoding is carried out on a plurality of discontinuous RP symbols which are successfully verified, and finally transmitted information source bit information is obtained;
s3: for the transmission rate of the EDD-CCM method, the transmission rate is related to the value range of the RP symbol and the length of the CRC check bit; defining the length of signed binary representation corresponding to the maximum value of RP symbols generated under a certain weight set to be L RP_bin CRC check bit length of L CRC The transmission rate of the EDD-CCM method can be expressed as
2. The adaptive rate adjustment method for fading channel based on EDD-CCM as claimed in claim 1, wherein in S2, in order to ensure a lower error detection probability, i.e. the successfully checked symbol is the completely correct symbol, a CRC error detection code with better error detection performance is used.
3. The adaptive rate adjustment method for fading channels based on EDD-CCM as claimed in claim 1, wherein the CRC check bit length needs to be chosen in compromise according to performance requirements.
4. The method as claimed in claim 1, wherein in S2, before performing RPC-BP decoding on a plurality of restored non-consecutive integer value RP symbols, rows of a generation matrix G are deleted correspondingly according to positions of the deleted RP symbols, that is, rows corresponding to RP symbols failed in detection in the G matrix are deleted correspondingly, then the RPC-BP decoding is performed on the G matrix after processing, and corresponding calculation is performed in the decoding process according to equations (1) and (2):
5. the method according to claim 1, wherein the specific processing flow at the receiving end in S2 is as follows: grouping QPSK demodulated bit information and CRC check information according to a pre-conversion principle at a receiving end, wherein each group represents an RP symbol; then, performing CRC (cyclic redundancy check) and RP (reverse protocol) symbol reduction on each group of bits, and deleting and marking the RP symbol position failed in verification; because each row of the generating matrix correspondingly generates an RP symbol, the rows of the decoding matrix (namely the generating matrix) are correspondingly deleted according to the marked position of the error symbol before the RP symbol is decoded after the error symbol is deleted; finally, the information source bit information b can be recovered by performing RPC-BP decoding by using the restored integer value RP symbol which is successfully checked 1 ,b 2 ,b 3 ,...b M 。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210836595.9A CN115174000A (en) | 2022-07-15 | 2022-07-15 | EDD-CCM-based adaptive adjustment method for rate under fading channel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210836595.9A CN115174000A (en) | 2022-07-15 | 2022-07-15 | EDD-CCM-based adaptive adjustment method for rate under fading channel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115174000A true CN115174000A (en) | 2022-10-11 |
Family
ID=83494457
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210836595.9A Pending CN115174000A (en) | 2022-07-15 | 2022-07-15 | EDD-CCM-based adaptive adjustment method for rate under fading channel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115174000A (en) |
-
2022
- 2022-07-15 CN CN202210836595.9A patent/CN115174000A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5123301B2 (en) | Encoding and decoding method and apparatus for use in a wireless communication system | |
| JP4575982B2 (en) | 16QAM signal space expansion | |
| JP4808722B2 (en) | Data transmission system and data transmission method | |
| CN101981850A (en) | Method and apparatus for storing log likelihood ratios in interleaved form to reduce hardware memory | |
| WO2009043312A1 (en) | Signal transmission method and apparatus for ofdma wireless communication system | |
| Jiang et al. | Using fountain codes to control the peak-to-average power ratio of OFDM signals | |
| KR20050116995A (en) | Apparatus and method for erasure detection and soft-decision decoding of cellular system receiver | |
| CN108809518B (en) | Method for constructing cascade Spinal code for reducing error performance | |
| CN111510199B (en) | Code modulation method and system in satellite mobile communication | |
| CN105453467A (en) | Transmission and receiving method in a wireless communication system | |
| CN1349699A (en) | Estimation method, receiver and decoder, of channel conditions in wireless communications | |
| US20040141458A1 (en) | Apparatus and method for reducing peak to average power ratio in an orthogonal frequency division multiplexing system | |
| JP4220365B2 (en) | Transmitting apparatus, receiving apparatus, data transmitting method, and data receiving method | |
| CN102415010B (en) | Systems and methods for retransmission return channel error detection | |
| CN115208736A (en) | High-order modulation constellation design method suitable for hybrid automatic repeat request system | |
| US7987413B2 (en) | Systems and methods for encoding a control channel in a wireless communication system | |
| Harley et al. | High-throughput covert channels in adaptive rate wireless communication systems | |
| CN113037298A (en) | System and method for filling interference information based on low-code-rate LDPC code | |
| CN110324065B (en) | Multi-user underwater acoustic communication method based on cyclic shift keying spread spectrum modulation | |
| CN115174000A (en) | EDD-CCM-based adaptive adjustment method for rate under fading channel | |
| JP4611864B2 (en) | Transmission method | |
| CN1326333C (en) | Data transmitting/receiving apparatus and method in radio system | |
| CN112039536B (en) | Adaptive polarization code coding and decoding method based on orthogonal frequency division multiplexing technology | |
| CN108432168A (en) | A kind of method and apparatus demodulated and decode | |
| CN106169946B (en) | A kind of method for reducing COFDM systems safety limit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |