CN106254031A - A kind of coding and decoding method and device - Google Patents

Abstract

The embodiment of the invention discloses a kind of coding and decoding method and device, described coded method includes: obtain the bit stream of preset length, and bit stream is divided into K layer；By BCH code, K/2 layer code element in K layer is encoded, the K/2 layer code element after output coding；By LDPC CC code, residue K/2 layer code element is encoded, the residue K/2 layer code element after output coding；Modulated by star qam mode, export modulated signal；Described interpretation method includes: obtain modulated signal；Demodulate and export modulated signal；By the decoded mode of hard decision, the K/2 layer demodulated signal in K layer is decoded, the code element after output decoding；By the decoded mode of soft-decision, residue K/2 layer demodulated signal is decoded, the code element after output decoding；Merge the code element after output decoding, be reduced to the bit stream of preset length.By the embodiment of the present invention, reduce the complexity of coding/decoding system, improve overall coding and decoding efficiency, reduce the bit error rate.

Description

Coding and decoding method and device

Technical Field

The present invention relates to encoding and decoding technologies, and in particular, to an encoding and decoding method and apparatus.

Background

In the current optical transmission system, OOK (On-off Keying) and QPSK (Quadrature Phase Shift Keying) modulation schemes are often used, and the coding process and the modulation process of the transmitting end are also considered separately. However, when the transmission rate in the transmission system reaches hundreds of Gbps, many technicians focus on the channel coding scheme and the channel modulation scheme in order to effectively increase the transmission rate and reduce the bit error rate of the optical system. Wherein, MLC (Multi-Level Coding) successfully realizes the fusion of Coding mode and modulation mode, and effectively improves the data transmission performance.

In the MLC system of the prior art, a coding device at a transmitting end performs bit grading on digital information, each grade performs coding in different coding modes, then performs mapping modulation, and transmits information obtained by modulation to a receiving end; a Decoding device corresponding to the encoding device at the receiving end demodulates the information mapped and modulated, and then performs MSD (Medium Specific Decoding) on the demodulated information. In the multi-stage decoding process, an iterative decoding mode is adopted for multi-stage decoding, the low-stage decoding result is transmitted to the next-stage decoding unit, and the next-stage decoding unit receives the decoding result of the previous-stage decoding unit and the demodulated information and then performs decoding.

Meanwhile, each stage in the prior art is coded by different coding modes, the coding process is more complicated in an optical system, and the MSD system adopts a soft decision mode, so that the complexity of a decoding system is increased, especially in a high-speed optical transmission system. In addition, in the existing multi-stage decoding mode, decoding modules at all stages are correlated, results influence each other, and complexity and bit error rate of a decoding iteration cycle are increased.

Disclosure of Invention

Embodiments of the present invention provide a coding and decoding method and apparatus, so as to reduce complexity of a coding and decoding system, improve overall coding and decoding efficiency, and reduce an error rate.

In order to achieve the above object, an embodiment of the present invention discloses an encoding method, including:

acquiring a bit stream with a preset length, and dividing the bit stream into K layers of bit streams, wherein each layer of bit stream corresponds to one code element, and K is greater than or equal to 2;

respectively obtaining each code element;

coding the code elements corresponding to the K/2 layers in the K layers through an error correcting code BCH code, and outputting the coded K/2 layers of code elements;

coding code elements corresponding to the residual K/2 layers in the K layers by using a low-density parity check convolutional code LDPC-CC code, and outputting the coded residual K/2 layers of code elements, wherein the sum of the K/2 layers and the residual K/2 layers is K layers;

and respectively modulating by a preset star Quadrature Amplitude Modulation (QAM) modulation mode according to the coded K/2 layer code element and the coded residual K/2 layer code elements, and outputting a modulated modulation signal.

Preferably, before the obtaining a bitstream with a preset length and dividing the bitstream into K layers of bitstreams, the method further includes:

and determining the code element rate of each code element and the coding efficiency of each layer in the K layer according to the QAM modulation mode to obtain the code element rate ratio of the coded K/2 layer code elements matched with the QAM modulation mode to the coded residual K/2 layer code elements.

Preferably, the modulating the coded K/2 layer symbols and the coded remaining K/2 layer symbols according to preset star-shaped quadrature amplitude modulation QAM modulation schemes, and outputting modulated modulation signals includes:

and mapping and modulating the coded K/2 layer code elements and the coded residual K/2 layer code elements respectively in the QAM modulation mode, and outputting modulated modulation signals.

In order to achieve the above object, an embodiment of the present invention discloses a decoding method, including:

acquiring a modulated signal;

demodulating the modulated modulation signal, and outputting a demodulated K/2 layer demodulation signal in a demodulated K layer and a demodulated residual K/2 layer demodulation signal in the demodulated K layer, wherein the sum of the K/2 layer and the residual K/2 layer is a K layer;

decoding the K/2 layer demodulation signal in a hard decision decoding mode, and outputting a code element corresponding to a K/2 layer in the decoded K layer;

transmitting the code elements corresponding to the K/2 layers in the K layers after decoding to the residual K/2 layers as prior information, decoding the residual K/2 layer demodulation signals and the prior information in a soft-decision decoding mode, and outputting the code elements corresponding to the residual K/2 layers in the K layers after decoding;

and combining the code elements corresponding to the K/2 layers in the decoded K layers and the code elements corresponding to the residual K/2 layers in the decoded K layers, and reducing the code elements into a bit stream with a preset length.

Preferably, when demodulating the modulated signal and outputting a demodulated K/2 layer demodulated signal in the demodulated K layer and a demodulated remaining K/2 layer demodulated signal in the demodulated K layer, the decoding method further includes:

and demodulating the modulated modulation signal, calculating log-likelihood ratio information of the residual K/2 layer demodulation signal, and outputting the log-likelihood ratio information.

Preferably, the decoding the K/2 layer demodulated signal by a hard-decision decoding manner, and outputting a decoded symbol corresponding to a K/2 layer in the K layer includes:

and decoding the K/2 layer demodulation signals in a decoding mode of error correcting code BCH hard decision, and outputting decoded code elements corresponding to the K/2 layer in the K layers.

Preferably, the transmitting the decoded symbols corresponding to the K/2 layers in the K layers to the remaining K/2 layers as prior information, decoding the remaining K/2 layer demodulation signal and the prior information in a soft-decision decoding manner, and outputting the decoded symbols corresponding to the remaining K/2 layers in the K layers includes:

and decoding the residual K/2 layer demodulation signals and the prior information in a decoding mode of low density parity check convolutional code LDPC-CC soft decision, and outputting code elements corresponding to the residual K/2 layers in the decoded K layers.

In order to achieve the above object, an embodiment of the present invention discloses an encoding apparatus, including:

the bit layering module is used for acquiring a bit stream with a preset length and dividing the bit stream into K layers of bit streams, wherein each layer of bit stream corresponds to one code element, and K is greater than or equal to 2;

the upper layer coding module is used for acquiring code elements corresponding to the K/2 layer in the K layer, coding the code elements corresponding to the K/2 layer in the K layer through an error correction code BCH code and outputting the coded K/2 layer code elements;

a lower layer coding module, configured to obtain code elements corresponding to remaining K/2 layers in the K layers, code the code elements corresponding to the remaining K/2 layers in the K layers by using a low density parity check convolutional code LDPC-CC code, and output coded remaining K/2 layers of code elements, where a sum of the K/2 layers and the remaining K/2 layers is a K layer;

and the modulation module is used for modulating the coded K/2 layer code elements and the coded residual K/2 layer code elements respectively in a preset star Quadrature Amplitude Modulation (QAM) modulation mode and outputting modulated modulation signals.

Preferably, the encoding apparatus further includes:

and the control module is used for determining the code element rate of each code element and the coding efficiency of each layer in the K layer according to the QAM modulation mode to obtain the code element rate ratio of the coded K/2 layer code elements to the coded residual K/2 layer code elements, which is matched with the QAM modulation mode.

In order to achieve the above object, an embodiment of the present invention further discloses a decoding apparatus, including:

the demodulation module is used for acquiring the modulated modulation signal; demodulating the modulated modulation signal, and outputting a demodulated K/2 layer demodulation signal in a demodulated K layer and a demodulated residual K/2 layer demodulation signal in the demodulated K layer, wherein the sum of the K/2 layer and the residual K/2 layer is a K layer;

an upper layer decoding module, configured to obtain the demodulated K/2 layer demodulated signal in the demodulated K layer, decode the demodulated K/2 layer signal in a hard decision decoding manner, and output a decoded symbol corresponding to the K/2 layer in the K layer;

a lower layer decoding module, configured to obtain the demodulated remaining K/2 layer demodulation signal in the K layer and a symbol corresponding to the K/2 layer in the K layer transmitted to the remaining K/2 layer as prior information, decode the remaining K/2 layer demodulation signal and the prior information in a soft-decision decoding manner, and output a decoded symbol corresponding to the remaining K/2 layer in the K layer;

and a merging output module, configured to merge the decoded code elements corresponding to the K/2 layers in the K layers and the decoded code elements corresponding to the remaining K/2 layers in the K layers, and reduce the decoded code elements into a bit stream with a preset length.

According to the technical scheme, the coding and decoding method and the device provided by the invention have the advantages that the error correction code BCH code and the low density parity check convolutional code LDPC-CC code are used for coding during coding, decoding is carried out in an error correction code BCH hard decision mode and a low density parity check convolutional code LDPC-CC soft decision mode during decoding, code elements corresponding to K/2 layers in the decoded K layers are transmitted to the residual K/2 layers as prior information, and the residual K/2 layers of demodulation signals and the prior information are decoded in a soft decision decoding mode, so that the complexity of a coding and decoding system can be effectively reduced, the whole coding and decoding efficiency is improved, and the error rate is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flow chart of an encoding method according to an embodiment of the present invention;

FIG. 2 is another flow chart of the encoding method according to the embodiment of the present invention;

FIG. 3 is a flowchart of a decoding method according to an embodiment of the present invention;

FIG. 4 is a block diagram of an encoding apparatus according to an embodiment of the present invention;

FIG. 5 is a block diagram of a four-layer encoding structure of an encoding apparatus according to an embodiment of the present invention;

FIG. 6 is a star QAM constellation according to an embodiment of the present invention;

FIG. 7 is a star QAM constellation of an embodiment of the present invention;

FIG. 8 is a block diagram of a decoding apparatus according to an embodiment of the present invention;

FIG. 9 is a block diagram of a four-layer decoding structure of a decoding device according to an embodiment 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.

Referring to fig. 1, fig. 1 is a flowchart of an encoding method according to an embodiment of the present invention, including:

s100: acquiring a bit stream with a preset length, and dividing the bit stream into K layers of bit streams, wherein each layer of bit stream corresponds to one code element, and K is greater than or equal to 2;

specifically, the preset length of the bit stream of the preset length is set according to requirements.

S110: respectively obtaining each code element;

s120: coding the code elements corresponding to the K/2 layer in the K layer through a BCH code (Bose, Ray-Chaudhuri and Hocquenghem, error correcting code), and outputting the coded K/2 layer code elements;

s130: encoding code elements corresponding to the remaining K/2 layers in the K layers by using an LDPC-CC (Low-density parity-check convolutional code), and outputting encoded remaining K/2 layers of code elements, wherein the sum of the K/2 layers and the remaining K/2 layers is the K layer;

specifically, S120 and S130 may be encoded simultaneously.

S140: and modulating the coded K/2 layer code elements and the coded residual K/2 layer code elements respectively by a preset star amplitude Modulation (QAM) Modulation mode, and outputting modulated Modulation signals.

Therefore, by the encoding method of the embodiment of the invention, after layering the bit stream, encoding the layered K-layer bit stream by the error correction code BCH code and the low density parity check convolutional code LDPC-CC code respectively, and the encoding complexity can be effectively reduced.

Specifically, the modulating the coded K/2 layer symbols and the coded remaining K/2 layer symbols respectively by a preset star QAM modulation scheme and outputting a modulated modulation signal includes:

and mapping and modulating the coded K/2 layer code elements and the coded residual K/2 layer code elements respectively in the QAM modulation mode, and outputting modulated modulation signals.

Specifically, the preset star QAM modulation scheme is a star QAM modulation scheme uniquely determined in a channel transmission system; in different channel transmission systems, the preset star QAM modulation schemes may be different, for example, the preset star QAM modulation scheme may be a star 16QAM modulation scheme, a star 32QAM modulation scheme, or a star 64QAM modulation scheme.

Referring to fig. 2, fig. 2 is another flowchart of an encoding method according to an embodiment of the present invention, including:

s200: determining the code element rate of each code element and the coding efficiency of each layer in the K layer according to a preset star Quadrature Amplitude Modulation (QAM) modulation mode;

s210: acquiring a bit stream with a preset length, and dividing the bit stream into K layers of bit streams, wherein each layer of bit stream corresponds to one code element, and K is greater than or equal to 2;

s220: respectively obtaining each code element;

s230: coding the code elements corresponding to the K/2 layers in the K layers through an error correcting code BCH code, and outputting the coded K/2 layers of code elements;

s240: coding code elements corresponding to the residual K/2 layers in the K layers by using a low-density parity check convolutional code LDPC-CC code, and outputting the coded residual K/2 layers of code elements, wherein the sum of the K/2 layers and the residual K/2 layers is K layers;

specifically, S230 and S240 may be encoded simultaneously.

S250: and respectively modulating by a preset star Quadrature Amplitude Modulation (QAM) modulation mode according to the coded K/2 layer code element and the coded residual K/2 layer code elements, and outputting a modulated modulation signal.

Therefore, by the encoding method of the embodiment of the invention, the code element rate of each code element and the encoding efficiency of each layer in the K layer can be determined according to the preset star quadrature amplitude modulation QAM modulation mode, so that different code element rates, encoding efficiencies and modulation modes are adopted in different channel transmission systems, the encoding efficiency is effectively improved, and the error rate in the encoding process is reduced.

Specifically, the preset length of the bit stream of the preset length is set according to requirements.

Specifically, the preset star QAM modulation scheme is a star QAM modulation scheme uniquely determined in a channel transmission system; in different channel transmission systems, the preset star QAM modulation schemes may be different, for example, the preset star QAM modulation scheme may be a star 16QAM modulation scheme, a star 32QAM modulation scheme, or a star 64QAM modulation scheme.

Specifically, the correspondence between the symbol rate, the coding efficiency, and the modulation scheme is shown in table 1, and after the star QAM modulation scheme is set, the coding efficiency and the symbol rate before coding can be adjusted according to table 1, so that the ratio of the symbol rate after coding matches the modulation scheme.

TABLE 1 relationship table of symbol rate, coding efficiency, modulation scheme

Modulation method	Coded symbol rate ratio	Coding efficiency ratio	Symbol rate ratio before coding
				Star 16QAM	1:1:1:1	1:1:1:1	1:1:1:1
Star 32QAM	2:1:1:1	1:1:1:1	1:2:2:2
				Star 64QAM	2:2:1:1	1:1:1:1	1:1:2:2

Referring to fig. 3, fig. 3 is a flowchart of a decoding method according to an embodiment of the present invention, including:

s300: acquiring a modulated signal;

s310: demodulating the modulated modulation signal, and outputting a demodulated K/2 layer demodulation signal in a demodulated K layer and a demodulated residual K/2 layer demodulation signal in the demodulated K layer, wherein the sum of the K/2 layer and the residual K/2 layer is a K layer;

s320: decoding the K/2 layer demodulation signal in a hard decision decoding mode, and outputting a code element corresponding to a K/2 layer in the decoded K layer;

specifically, the decoding the K/2 layer demodulated signal in a hard-decision decoding manner, and outputting a decoded symbol corresponding to a K/2 layer in the K layer includes:

and decoding the K/2 layer demodulation signals in a decoding mode of error correcting code BCH hard decision, and outputting decoded code elements corresponding to the K/2 layer in the K layers.

S330: transmitting the code elements corresponding to the K/2 layers in the K layers after decoding to the residual K/2 layers as prior information, decoding the residual K/2 layer demodulation signals and the prior information in a soft-decision decoding mode, and outputting the code elements corresponding to the residual K/2 layers in the K layers after decoding;

specifically, the transmitting the decoded code elements corresponding to the K/2 layers in the K layers to the remaining K/2 layers as prior information, decoding the remaining K/2 layer demodulation signals and the prior information in a soft-decision decoding manner, and outputting the decoded code elements corresponding to the remaining K/2 layers in the K layers includes:

and decoding the residual K/2 layer demodulation signals and the prior information in a decoding mode of low density parity check convolutional code LDPC-CC soft decision, and outputting code elements corresponding to the residual K/2 layers in the decoded K layers.

Further, the prior information is symbols corresponding to K/2 layers of the K layers after the decoding.

S340: and combining the code elements corresponding to the K/2 layers in the K layers after the output decoding and the code elements corresponding to the residual K/2 layers in the K layers after the decoding, and reducing the code elements into a bit stream with a preset length.

Specifically, when demodulating the modulated signal and outputting a demodulated K/2 layer demodulated signal in the demodulated K layer and a demodulated remaining K/2 layer demodulated signal in the demodulated K layer, the decoding method further includes:

and demodulating the modulated modulation signal, calculating log-likelihood ratio information of the residual K/2 layer demodulation signal, and outputting the log-likelihood ratio information.

Specifically, the log likelihood ratio information is obtained by the following formula:

$LLR\left(b_t^k\right)=ln\frac{E_{a\∈A(v_t^0,...,v_t^{k-1},0)\left\{p(Y=y_t|X=a)\right\}}}{E_{a\∈A(v_t^0,...,v_t^{k-1},1)\left\{p(Y=y_t|X=a)\right\}}}$

wherein,for log-likelihood ratio information, E for averaging,the ith bit of the signal label in the signal set A is taken asA is an element of set a,p (Y) is a demodulation signal of the k-th layer_tWhere | X ═ a) is the conditional probability, k is the number of layers,is the coded bit of the k-th layer.

It can be seen that, by the decoding method of the embodiment of the present invention, when decoding is performed using an error correction code BCH code and a low density parity check convolutional code LDPC-CC code, the code elements corresponding to the K/2 layers in the decoded K layers are transmitted to the remaining K/2 layers as prior information, and are decoded together with the demodulated signals of the remaining K/2 layers, so that the dependency of the lower layer decoding on the upper layer decoding can be effectively reduced, and the error rate of the decoding is reduced.

Referring to fig. 4, fig. 4 is a block diagram of an encoding apparatus according to an embodiment of the present invention; the method comprises the following steps:

a bit layering module 400, configured to obtain a bit stream with a preset length, and divide the bit stream into K layers of bit streams, where each layer of bit stream corresponds to one symbol, and K is greater than or equal to 2;

an upper layer encoding module 410, configured to acquire a symbol corresponding to a K/2 layer in the K layer, encode the symbol corresponding to the K/2 layer in the K layer by using an error correction code BCH code, and output the encoded K/2 layer symbol;

a lower layer encoding module 420, configured to obtain code elements corresponding to remaining K/2 layers in the K layers, encode the code elements corresponding to the remaining K/2 layers in the K layers by using a low density parity check convolutional code LDPC-CC code, and output encoded remaining K/2 layers of code elements, where a sum of the K/2 layers and the remaining K/2 layers is a K layer;

specifically, the upper layer encoding module 410 and the lower layer encoding module 420 may perform encoding simultaneously.

And a modulation module 430, configured to perform modulation according to the encoded K/2 layer symbol and the encoded remaining K/2 layer symbol respectively by using a preset star quadrature amplitude modulation QAM modulation scheme, and output a modulated modulation signal.

Therefore, the encoding device of the embodiment of the invention maps and modulates through a star QAM modulation mode, has stronger adaptability to channel fading, and has better tolerance to the line width of a transmitting laser.

Specifically, the encoding device further includes:

and the control module is used for determining the code element rate of each code element and the coding efficiency of each layer in the K layers according to a preset star Quadrature Amplitude Modulation (QAM) modulation mode, so that the code element rate of the coded K/2 layers of code elements and the code element rate ratio of the coded residual K/2 layers of code elements are matched with the modulation mode.

Specifically, the modulation module 430 further includes:

and the mapping submodule is used for respectively carrying out mapping modulation through the QAM modulation mode according to the coded K/2 layer code element and the coded residual K/2 layer code element and outputting a modulated modulation signal.

It should be noted that, the apparatus according to the embodiment of the present invention is an apparatus applying the above encoding method, and all embodiments of the above encoding method are applicable to the apparatus and can achieve the same or similar beneficial effects.

To more clearly illustrate the encoding apparatus according to the embodiment of the present invention, a four-layer encoding and a star 16QAM modulation scheme are taken as an example, as shown in fig. 5:

in a channel transmission system, firstly, determining a modulation mode as a star quadrature amplitude modulation 16QAM modulation mode;

the bit layering module 500 obtains a bit stream with a preset length of L, and divides the bit stream with the preset length of L into four layers, where the code elements of each layer are: s₀、S₁、S₂、S₃；

The first BCH coding module 510 and the second BCH coding module 520 in the upper layer coding module respectively pair S₀、S₁The code element is coded, and a first LDPC-CC coding module 530 and a second LDPC-CC coding module 540 in the lower layer coding module respectively code S₂、S₃Coding the code element, and outputting the coded code element after the coding is finished as follows: b₀、b₁、b₂、b₃；

The modulation module 550 processes the coded symbol b₀、b₁、b₂、b₃And carrying out star quadrature amplitude modulation 16QAM mapping modulation and outputting a modulated signal. As shown in FIG. 6, which is a star QAM constellation diagram, the dotted circle 610 indicates S0 is 0₁、S₂、S₃Mapping of three layers; dotted circle 620 indicates that b0 is 1, S₁、S₂、S₃Mapping of three layers;

when using 32QAM, the constellation of the mapped modulation is shown in fig. 7, with dashed circle 710 indicating 0 for b1, S₀、S₂、S₃Mapping of three layers; dotted circle 720 indicates that when b1 is 1, S₀、S₂、S₃Three-level mapping, with dashed circle 730 indicating 0 for b0, S₁、S₂、S₃Mapping of three layers; dotted circle 740 indicates that b0 is 1, S₁、S₂、S₃And mapping three layers.

Referring to fig. 8, fig. 8 is a block diagram of a decoding apparatus according to an embodiment of the present invention, including:

a demodulation module 800, configured to obtain the modulated modulation signal; demodulating the modulated modulation signal, and outputting a demodulated K/2 layer demodulation signal in a demodulated K layer and a demodulated residual K/2 layer demodulation signal in the demodulated K layer, wherein the sum of the K/2 layer and the residual K/2 layer is a K layer;

an upper decoding module 810, configured to obtain a K/2 layer demodulation signal in the demodulated K layer, decode the K/2 layer demodulation signal in a hard decision decoding manner, and output a decoded symbol corresponding to the K/2 layer in the K layer;

a lower layer decoding module 820, configured to obtain the demodulated remaining K/2 layer demodulated signal in the K layer and the symbol corresponding to the K/2 layer in the K layer transmitted to the remaining K/2 layer as the priori information, decode the remaining K/2 layer demodulated signal and the priori information in a soft-decision decoding manner, and output the decoded symbol corresponding to the remaining K/2 layer in the K layer;

a merging output module 830, configured to merge the decoded symbols corresponding to the K/2 layers in the K layers and the decoded symbols corresponding to the remaining K/2 layers in the K layers, and restore the decoded symbols to a bitstream with a preset length.

Specifically, the lower layer decoding module 820 further includes:

and the log-likelihood ratio calculation submodule is used for acquiring the demodulated information, calculating the log-likelihood ratio information of the residual K/2 layer demodulated signals and outputting the log-likelihood ratio information.

Specifically, the upper layer decoding module 810 is further configured to decode the K/2 layer demodulated signal in a decoding manner of an error correction code BCH hard decision, and output a decoded symbol corresponding to the K/2 layer in the K layers.

Specifically, the lower layer decoding module 820 is further configured to decode the remaining K/2 layer demodulation signal and the priori information by using a decoding manner of low density parity check convolutional code LDPC-CC soft decision, and output a symbol corresponding to the remaining K/2 layer in the K layers after decoding.

It should be noted that, the apparatus according to the embodiment of the present invention is an apparatus applying the decoding method, and all embodiments of the decoding method are applicable to the apparatus and can achieve the same or similar beneficial effects.

To more clearly explain the decoding apparatus according to the embodiment of the present invention, a four-layer decoding is taken as an example to explain, and corresponds to an encoding apparatus for four-layer encoding, as shown in fig. 9, fig. 9 is a block diagram of a four-layer decoding structure of the decoding apparatus according to the embodiment of the present invention, and includes:

a demodulation module 900, configured to obtain the modulated modulation signal; demodulating the modulated signals to obtain demodulated signals b'₀、b'₁、b'₂、b'₃；

The first BCH code decoding module 910 and the second BCH code decoding module 920 decode the demodulated signal b 'in a hard decision decoding manner'₀、b'₁Decoding is carried out, and decoded symbol S 'is output'₀、S'₁；

The first LDPC-CC code decoding module 930 and the second LDPC-CC code decoding module 940 decode the demodulated signal b 'in a soft decision decoding manner'₂、b'₃Decoding and outputting the decodedCode element S'₂、S'₃；

Specifically, the decoded symbols S 'output by the first BCH code decoding module 910'₀Is input as prior information to the first LDPC-CC code decoding module 930 and the demodulated signal b'₂Jointly decoded and output decoded symbol S'₂；

The decoded symbol S 'output by the second BCH code decoding module 920'₁Is input as prior information to the second LDPC-CC code decoding module 940 and the demodulated signal b'₃Jointly decoded and output decoded symbol S'₃。

Further, the demodulation module 900 and the first LDPC-CC code decoding module 930 further include:

a first demapping module, configured to generate first log-likelihood ratio information required for decoding by the first LDPC-CC code decoding module 930.

Between the demodulation module 900 and the second LDPC-CC code decoding module 940, the four-layer encoding apparatus further includes:

and a second demapping module, configured to generate second log likelihood ratio information required for decoding by the second LDPC-CC code decoding module 940.

The merging output module 950 respectively obtains the symbols S 'decoded by the first BCH code decoding module 910'₀And the symbol S 'decoded by the second BCH code decoding module 920'₁And the decoded symbol S 'of the first LDPC-CC code decoding module 930'₂And a symbol S 'decoded by the second LDPC-CC code decoding module 940'₃And merging the bit streams, reducing the bit streams into bit streams with the preset length L, and outputting the bit streams with the preset length L.

Therefore, according to the coding and decoding method and system provided by the embodiment of the invention, layered coding and layered decoding are adopted, and during decoding, a decoded code element output by an upper layer decoding module is input to a lower layer decoding module as prior information. The complexity of a coding and decoding system can be effectively reduced, the coding and decoding efficiency is improved, and the dependence on an upper level and the error rate in the decoding process are reduced.

All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. A method of encoding, comprising:

acquiring a bit stream with a preset length, and dividing the bit stream into K layers of bit streams, wherein each layer of bit stream corresponds to one code element, and K is greater than or equal to 2;

respectively obtaining each code element;

coding the code elements corresponding to the K/2 layers in the K layers through an error correcting code BCH code, and outputting the coded K/2 layers of code elements;

coding code elements corresponding to the residual K/2 layers in the K layers by using a low-density parity check convolutional code LDPC-CC code, and outputting the coded residual K/2 layers of code elements, wherein the sum of the K/2 layers and the residual K/2 layers is K layers;

and respectively modulating by a preset star Quadrature Amplitude Modulation (QAM) modulation mode according to the coded K/2 layer code element and the coded residual K/2 layer code elements, and outputting a modulated modulation signal.

2. The encoding method according to claim 1, wherein before the obtaining a bit stream with a preset length and dividing the bit stream into K-layer bit streams, the encoding method further comprises:

and determining the code element rate of each code element and the coding efficiency of each layer in the K layer according to the QAM modulation mode to obtain the code element rate ratio of the coded K/2 layer code elements matched with the QAM modulation mode to the coded residual K/2 layer code elements.

3. The encoding method according to claim 1, wherein the modulating according to the encoded K/2 layer symbols and the encoded remaining K/2 layer symbols by a preset star-quadrature amplitude modulation QAM modulation scheme to output a modulated modulation signal comprises:

and mapping and modulating the coded K/2 layer code elements and the coded residual K/2 layer code elements respectively in the QAM modulation mode, and outputting modulated modulation signals.

4. A decoding method, comprising:

acquiring a modulated signal;

demodulating the modulated modulation signal, and outputting a demodulated K/2 layer demodulation signal in a demodulated K layer and a demodulated residual K/2 layer demodulation signal in the demodulated K layer, wherein the sum of the K/2 layer and the residual K/2 layer is a K layer;

decoding the K/2 layer demodulation signal in a hard decision decoding mode, and outputting a code element corresponding to a K/2 layer in the decoded K layer;

transmitting the code elements corresponding to the K/2 layers in the K layers after decoding to the residual K/2 layers as prior information, decoding the residual K/2 layer demodulation signals and the prior information in a soft-decision decoding mode, and outputting the code elements corresponding to the residual K/2 layers in the K layers after decoding;

and combining the code elements corresponding to the K/2 layers in the decoded K layers and the code elements corresponding to the residual K/2 layers in the decoded K layers, and reducing the code elements into a bit stream with a preset length.

5. The decoding method according to claim 4, wherein in said demodulating the modulated signal, outputting a demodulated signal of K/2 layers of the demodulated K layers and a demodulated signal of remaining K/2 layers of the demodulated K layers, the decoding method further comprises:

and demodulating the modulated modulation signal, calculating log-likelihood ratio information of the residual K/2 layer demodulation signal, and outputting the log-likelihood ratio information.

6. The decoding method according to claim 4, wherein the decoding the demodulated signals of K/2 layers by a hard-decision decoding manner to output decoded symbols corresponding to K/2 layers in the K layers comprises:

and decoding the K/2 layer demodulation signals in a decoding mode of error correcting code BCH hard decision, and outputting decoded code elements corresponding to the K/2 layer in the K layers.

7. The decoding method according to claim 4, wherein the transmitting the decoded symbols corresponding to the K/2 layers in the K layers to the remaining K/2 layers as prior information, decoding the remaining K/2 layer demodulation signal and the prior information by a soft-decision decoding method, and outputting the decoded symbols corresponding to the remaining K/2 layers in the K layers comprises:

and decoding the residual K/2 layer demodulation signals and the prior information in a decoding mode of low density parity check convolutional code LDPC-CC soft decision, and outputting code elements corresponding to the residual K/2 layers in the decoded K layers.

8. An encoding apparatus, comprising:

the bit layering module is used for acquiring a bit stream with a preset length and dividing the bit stream into K layers of bit streams, wherein each layer of bit stream corresponds to one code element, and K is greater than or equal to 2;

the upper layer coding module is used for acquiring code elements corresponding to the K/2 layer in the K layer, coding the code elements corresponding to the K/2 layer in the K layer through an error correction code BCH code and outputting the coded K/2 layer code elements;

a lower layer coding module, configured to obtain code elements corresponding to remaining K/2 layers in the K layers, code the code elements corresponding to the remaining K/2 layers in the K layers by using a low density parity check convolutional code LDPC-CC code, and output coded remaining K/2 layers of code elements, where a sum of the K/2 layers and the remaining K/2 layers is a K layer;

and the modulation module is used for modulating the coded K/2 layer code elements and the coded residual K/2 layer code elements respectively in a preset star Quadrature Amplitude Modulation (QAM) modulation mode and outputting modulated modulation signals.

9. The encoding device according to claim 8, wherein the encoding device further comprises:

and the control module is used for determining the code element rate of each code element and the coding efficiency of each layer in the K layer according to the QAM modulation mode to obtain the code element rate ratio of the coded K/2 layer code elements to the coded residual K/2 layer code elements, which is matched with the QAM modulation mode.

10. A decoding apparatus, comprising:

the demodulation module is used for acquiring the modulated modulation signal; demodulating the modulated modulation signal, and outputting a demodulated K/2 layer demodulation signal in a demodulated K layer and a demodulated residual K/2 layer demodulation signal in the demodulated K layer, wherein the sum of the K/2 layer and the residual K/2 layer is a K layer;

an upper layer decoding module, configured to obtain the demodulated K/2 layer demodulated signal in the demodulated K layer, decode the demodulated K/2 layer signal in a hard decision decoding manner, and output a decoded symbol corresponding to the K/2 layer in the K layer;

a lower layer decoding module, configured to obtain the demodulated remaining K/2 layer demodulation signal in the K layer and a symbol corresponding to the K/2 layer in the K layer transmitted to the remaining K/2 layer as prior information, decode the remaining K/2 layer demodulation signal and the prior information in a soft-decision decoding manner, and output a decoded symbol corresponding to the remaining K/2 layer in the K layer;

and a merging output module, configured to merge the decoded code elements corresponding to the K/2 layers in the K layers and the decoded code elements corresponding to the remaining K/2 layers in the K layers, and reduce the decoded code elements into a bit stream with a preset length.