The present invention relates to the field of encoder/decoder design and particularly to a system and method for using the universal multipole for the implementation of a configurable binary Bose-Chaudhuri-Hocquenghem (BCH) encoder with variable number of errors.
Currently available encoders/decoders may not provide a desired level of performance.
Therefore, it may be desirable to provide a solution which addresses the above-referenced problems associated with current encoders/decoders.
Accordingly, an embodiment of the present invention is directed to an encoder, including: a plurality of register blocks; a plurality of adder logic blocks, said plurality of adder logic blocks being communicatively coupled with the plurality of register blocks; a switching logic block, said switching logic block being communicatively coupled with the plurality of adder logic blocks, said switching logic block being configured for receiving a plurality of information bits of an information word received by the encoder, said switching logic further configured for generating a first output based on a first set of information bits included in the plurality of information bits, said switching logic block further configured for generating a second output based on a second set of information bits included in the plurality of information bits, said switching logic block further configured for providing the second output to the plurality of adder logic blocks; and a universal multipole block, said universal multipole block being communicatively coupled with the plurality of adder logic blocks, said universal multipole block being configured for receiving an error number input, said universal multipole block further configured for calculating a plurality of error coefficients based on the error number input, said universal multipole block further configured for outputting the plurality of coefficients to the adder logic blocks, wherein the adder logic blocks are configured for calculating a plurality of parity bits based on the error coefficients received from the universal multipole block and further based on the second output received from the switching logic block, said adder logic blocks further configured for providing the parity bits to the plurality of register blocks, the encoder configured for outputting the parity bits and the first output of the switching logic block.
A further embodiment of the present invention is directed to a method for providing an encoder having a variable number of errors, including: receiving an error number input; calculating a plurality of error coefficients based on the error number input; providing the error coefficients to a plurality of adder logic blocks; and receiving a data receive signal via a data enable input.
An additional embodiment of the present invention is directed to a computer-readable medium having computer-executable instructions for performing a method for providing an encoder having a variable number of errors, said method including: receiving an error number input; calculating a plurality of error coefficients based on the error number input; providing the error coefficients to a plurality of adder logic blocks; receiving a data receive signal via a data enable input; and receiving an information word via a data input.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not necessarily restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description, serve to explain the principles of the invention.
The numerous advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying figures in which:
Bose-Chaudhuri-Hocquenghem (BCH) codes compose a large class of multiple error-correcting codes. Binary BCH codes were discovered in 1959 by Hocquenghem and independently in 1960 by Bose and Ray-Chaudhuri. Later, Gorenstein and Zierler generalized BCH codes to all finite fields. At about that same time, Reed and Solomon published their paper on the special case of BCH codes which now bear their names. In practice, binary BCH codes and binary Reed-Solomon codes are the most commonly used variants of BCH codes.
The binary BCH codes and binary Reed-Solomon codes have applications in a variety of communication systems, such as: space communication links, digital subscriber loops, wireless systems, networking communications systems, and magnetic and data storage systems. Continual demand for ever higher data rates and storage capacity makes it necessary to devise very high-speed and space-efficient Very Large Scale Integration (VLSI) implementations of BCH decoders. The first decoding algorithm for binary BCH codes was proposed by Peterson in 1960. Since then, Peterson's algorithm has been refined by Gorenstein, Zierler, Berlekamp, Massey, Chien, Forney and many others. Let GF(q) be a finite field of q elements, q=2s, called base field, and let α be a primitive element of extension field GF(qm), where n|qm−1. Define t error detecting BCH code of length n over GF(q) as the set of all sequences (c0, c1, . . . , cn−1), ciεGF(q) such that polynomial
c(x)=c0+c1x+ . . . +cn−1xn−1εGF(qm)[x]
has roots in points: α1, α2, . . . , α2t. BCH code with m=1 is called Reed Solomon code, and with s=1 binary BCH code.
Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings.
Referring generally to
In current embodiments of the present invention, the encoder 100 may include a universal multipole block (ex.—block U) 108. The universal multipole block 108 may be configured for receiving the error number input 102. Further, the universal multipole block 108 may be configured for calculating one or more error coefficients based on the error number input 102. Still further, the universal multipole block 108 may be configured for providing the error coefficients to one or more adder logic blocks/adders (ex.—blocks A0, A1 . . . Aq−1) 110, said adder logic blocks 110 being communicatively coupled to the universal multipole block 108. For example, the error coefficients may be transmitted to the adder logic blocks 110 via a parallel transmission (as shown in
Universal multipole for variables x1, x2, . . . , xn is a scheme with n inputs and 22
As mentioned above, the encoder 100 of the present invention may be configured for receiving a data input 106. Further, the encoder 100 may be configured for receiving an information word (ex.—a word to be encoded) via the received data input 106. For instance, the information word may include a plurality of information bits, which may be received by the encoder in a singular manner (ex.—one bit at a time).
As mentioned above, the encoder 100 of the present invention may be configured for receiving a data enable input 104. Further, the encoder 100 may be configured for receiving a data receive signal via the received data enable input 104. The data receive signal may signal the encoder 100 that said encoder is ready to begin/may begin/is cleared or allowed to begin/should begin/is about to begin receiving the data input 106 (ex.—the encoder may begin receiving information bits of the information word/bits of the information word may begin to be fed into the encoder). Further, the data receive signal may cause the encoder 100 to begin receiving the data input 106 (ex.—the information word). For example, the data receive signal of the received data enable input 104 may be/include a value equal to 1.
In further embodiments, as the plurality of information bits of the information word are being fed into the encoder 100, said plurality of information bits are provided to a switch logic block/switching logic block 112 (ex.—S block) of the encoder 100. The switch logic block 112 is configured for generating a first output based on a first set of information bits included in the plurality of information bits. Further, the switch logic block 112 may be configured for directing the first output (ex.—the unmodified first set of information bits) to a register block (ex.—a D block/block of registers) included in a plurality of register blocks 114, said register block 114 being communicatively coupled with the switch logic block 112. Said register blocks/D blocks 114 may be implemented as part of a linear shift register 116 of the encoder 100. Further said first output (ex.—the unmodified first set of information bits) may be transmitted from encoder 100 via/as part of encoder output 118 (shown as c in
In current embodiments of the present invention, the switch logic block 112 may be configured for generating a second output based on a second set of information bits included in the plurality of information bits/information symbols. Further, the switch logic block 112 may be configured for directing the second output to the plurality of adder logic blocks 110, said adder logic blocks 110 being communicatively coupled with the switch logic block 112. For example, the second output may be transmitted via a parallel transmission from the switch logic block 112 to the adder logic blocks 110 (as shown in
xi=qw−1−i, i=0, 1, . . . , w=1;
vi=((xi+di)mod 2)&en, i=0, 1, . . . , w−1;
ci=(en&di)(en&xi), i=0, 1, . . . , w−1.
In exemplary embodiments, the adders/adder logic blocks (ex.—the A blocks) 110 are communicatively coupled with the switch logic block 112 and are configured for receiving the second output based from the switch logic block 112. Further, the adders/adder logic blocks/A blocks 110 are communicatively coupled with the universal multipole block/U block 108 and are configured for receiving the error coefficients from the universal multipole block 108. Further, the adder logic blocks 110 are configured for calculating a plurality of parity bits/parity symbols based on the received error coefficients and the received second output. For instance, the number of parity bits may be precisely defined by the maximum error limit specified in the error number input and/or the error coefficients. Once the adder logic blocks 110 have calculated the parity bits, said parity bits may be provided to the register blocks/D blocks 114 (as shown in
Inputs and outputs of the adder logic blocks/A blocks 110 (ex.—blocks A0 and Ai, i=1, 2, . . . , p−1) are shown in
Denote m=w if p|w, otherwise m=p mod w. An auxiliary matrix, (fijk), i=0, 1, . . . , q−1, j=0, 1, . . . , w−1, k=0, 1, . . . , w−1, may be constructed where
The functioning of the block A0 may be described by the formulas
For any i=1, 2, . . . , q−1, the functioning of the block Ai may be described by the formulas
Note that fijk are constants, therefore blocks Ai, i=0, 1, . . . , q−1, may be adders.
As mentioned above, the encoder 100 of the present invention may be a binary BCH encoder. During encoding of binary BCH codes, a generator polynomial g(x)εGF(2) may be calculated:
g(x)=LCM{M1(x), M2(x), . . . , M2t(x)},
where LCM may be the least common multiplier and Mi(x) may be the minimal polynomial for αi. Let p=deg g(x) be the degree of the generator polynomial and k=n-p be the number of data symbols. Let (d0, d1, . . . , dk−1) denote k data symbols that are to be transmitted over a communication channel and d(x)=d0+d1x+ . . . dk−1xk−1 εGF(2)[x]. The systematic encoding of vector (d0, d1, . . . , dk−1) into a codeword (c0, c1, . . . . , cn−1) may be as follows:
c(x)=xn-pd(x)+t(x),
where t(x)=xn-pd(x) mod g(x), c(x)=c0+c1x+ . . . +cn−1xn−1. Let w be the bus width of the encoder. Write n|w if n divides by w. Denote r=w if n|w, otherwise r=n mod w. For simplicity, we may suppose that k|w. When input data is transmitted to the encoder 100, input data_en 104 may be high. Further, delay of the encoder 100 may be equal to 1. Let ]n[ be the least integer less or equal to n. Denote q=]p/w[. In further embodiments, the encoder 100 may be implemented by a linear feedback shift register (LFSR).
Further, as mentioned above, the encoder 100 may be a configurable binary BCH encoder with a variable number of errors. The functionality of the encoder 100, having a variable number of errors for binary BCH codes may be described as follows:
Let {t0, t1, . . . , te−1} be a set of integers such that t0>t1> . . . >te−1. Encoder 100, with variable number of errors or encoder for set of error numbers {t0, t1, . . . , te−1} may have an additional input, called err_num 102. This input may be log2 e bits wide. If err_num=s ε{0, 1, . . . , e−1} then the encoder 100 may generate codes correcting tS errors. Each adder logic block, Ai, i=0, 1, . . . , q−1, may have an additional input err_num (for receiving data from the universal multipole block 108, as shown in
Let gs(x)=g0+g1x+ . . . +gp
Construct an auxiliary matrix (fijks), i=0, 1, . . . , q−1, j=0, 1, . . . , w−1, k=0, 1, . . . , w−1, where
The functioning of the block A0 may be described by the formulas:
Here mux(l, x0, . . . , xe−1)=x1 may be a multiplexer. For any i=1, 2, . . . , q−1, the functioning of the block Ai may be described by the formulas:
If we compare the ordinary encoder and the encoder with variable number of errors then we can see that the encoder with variable number of errors has w2q additional multiplexers.
As mentioned above, once the adder logic blocks 110 have calculated the parity bits, said parity bits may be provided to the register blocks/D blocks 114 (as shown in
In further embodiments, the data enable input 104 may provide a data receive signal, which may be/may include/may specify a value, such as 1. The data receive signal may cause the encoder 100 to begin receiving the information word. Further, the data receive signal may remain in effect/the data enable input may continue to include/specify a value of 1 until: every information bit of the information word has been received by the encoder 100; and every parity bit for the information word has been calculated and provided to the linear shift register 116 of the encoder. Once these conditions are met, the data enable input 104 may provide a data shift signal, which may be/may include/may specify a value, such as 0. The data shift signal may cause the encoder 100 to begin shifting the parity bits along the linear shift register 116 (as shown in
It is to be noted that the foregoing described embodiments according to the present invention may be conveniently implemented using conventional general purpose digital computers programmed according to the teachings of the present specification, as will be apparent to those skilled in the computer art. Appropriate software coding may readily be prepared by skilled programmers based on the teachings of the present disclosure, as will be apparent to those skilled in the software art.
It is to be understood that the present invention may be conveniently implemented in forms of a software package. Such a software package may be a computer program product which employs a computer-readable storage medium including stored computer code which is used to program a computer to perform the disclosed function and process of the present invention. The computer-readable medium may include, but is not limited to, any type of conventional floppy disk, optical disk, CD-ROM, magnetic disk, hard disk drive, magneto-optical disk, ROM, RAM, EPROM, EEPROM, magnetic or optical card, or any other suitable media for storing electronic instructions.
It is understood that the specific order or hierarchy of steps in the foregoing disclosed methods are examples of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the method can be rearranged while remaining within the scope of the present invention. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.
It is believed that the present invention and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely an explanatory embodiment thereof, it is the intention of the following claims to encompass and include such changes.
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