A system and method for DC balanced transition encoding. In some embodiments, the method includes: generating a set of candidate encoding keys for a set of raw data words; selecting a first encoding key, of the set of candidate encoding keys, based on a first disparity contribution; and encoding the raw data words with the first encoding key, the first disparity contribution being a difference between the number of ones and the number of zeros in the result of encoding the set of raw data words with the first encoding key.

One aspect of the present disclosure relates to a conversion device including an acquisition unit configured to acquire a first bit string having a first bit length L1; a conversion unit configured to convert, in accordance with conversion information that associates respective bit strings each having the first bit length L1 with bit strings each having a second bit length L2 uniquely assigned to the respective bit strings, the first bit string into a second bit string having the second bit length L2. The conversion information is created by searching for a clique that includes 2.sup.L1 or more nodes, from a graph including nodes and an edge representing the bit strings each having the second bit length L2 that satisfy a predetermined constraint condition.

A computer-implemented method for compressing, an input group of m data values compresses the two least significant bits of each of the data values by mapping the two least significant bits of each of the data values in the input group of m data values collectively onto an m-bit encoding and storing the m-bit encoding, the m-bit encoding being selected from 2.sup.m m-bit encodings, the 2.sup.m m-bit encodings comprising a first group of encodings comprising (2.sup.m4) m-bit encodings and a second group of encodings comprising four m-bit encodings, wherein if the selected encoding is an encoding from the first group of encodings then the selected encoding represents the two least significant bits for a representative group of m data values in which the second least significant bit of each of the data values is the same as a respective bit of the m-bit encoding, and wherein if the selected encoding is an encoding from the second group of encodings then the selected encoding represents the two least significant bits for a representative group of m data values in which the two least significant bits for each of the data values in the representative group are equal to the two least significant bits of the other data values in the representative group.

A computer-implemented method for compressing, an input group of m data values compresses the two least significant bits of each of the data values by mapping the two least significant bits of each of the data values in the input group of m data values collectively onto an m-bit encoding and storing the m-bit encoding, the m-bit encoding being selected from 2.sup.m m-bit encodings, the 2.sup.m m-bit encodings comprising a first group of encodings comprising (2.sup.m4) m-bit encodings and a second group of encodings comprising four m-bit encodings, wherein if the selected encoding is an encoding from the first group of encodings then the selected encoding represents the two least significant bits for a representative group of m data values in which the second least significant bit of each of the data values is the same as a respective bit of the m-bit encoding, and wherein if the selected encoding is an encoding from the second group of encodings then the selected encoding represents the two least significant bits for a representative group of m data values in which the two least significant bits for each of the data values in the representative group are equal to the two least significant bits of the other data values in the representative group.

A communications device includes a mapping module mapping a plurality of n-bit signals to a plurality of (n+1)/2 symbols using a first or second set of symbols having a positive or negative disparity. An encoder a) selects the first set of symbols or the second set of symbols as a next symbol set of the mapping module; b) encodes a first one of the plurality of n-bit signals using the next symbol set of the mapping module; c) calculates a running disparity; d) if the running disparity is greater than zero, selects the second set of symbols of the mapping module as the next symbol set; and e) if the running disparity is less than zero, selects the first set of symbols of the mapping module as the next symbol set.

A communications device includes a mapping module mapping a plurality of n-bit signals to a plurality of (n+1)/2 symbols using a first or second set of symbols having a positive or negative disparity. An encoder a) selects the first set of symbols or the second set of symbols as a next symbol set of the mapping module; b) encodes a first one of the plurality of n-bit signals using the next symbol set of the mapping module; c) calculates a running disparity; d) if the running disparity is greater than zero, selects the second set of symbols of the mapping module as the next symbol set; and e) if the running disparity is less than zero, selects the first set of symbols of the mapping module as the next symbol set.

A computer-implemented method for compressing, an input group of m data values compresses the two least significant bits of each of the data values by mapping the two least significant bits of each of the data values in the input group of m data values collectively onto an m-bit encoding and storing the m-bit encoding, the m-bit encoding being selected from 2.sup.m m-bit encodings, the 2.sup.m m-bit encodings comprising a first group of encodings comprising (2.sup.m4) m-bit encodings and a second group of encodings comprising four m-bit encodings, wherein if the selected encoding is an encoding from the first group of encodings then the selected encoding represents the two least significant bits for a representative group of m data values in which the second least significant bit of each of the data values is the same as a respective bit of the m-bit encoding, and wherein if the selected encoding is an encoding from the second group of encodings then the selected encoding represents the two least significant bits for a representative group of m data values in which the two least significant bits for each of the data values in the representative group are equal to the two least significant bits of the other data values in the representative group.

A computer-implemented method for compressing, an input group of m data values compresses the two least significant bits of each of the data values by mapping the two least significant bits of each of the data values in the input group of m data values collectively onto an m-bit encoding and storing the m-bit encoding, the m-bit encoding being selected from 2.sup.m m-bit encodings, the 2.sup.m m-bit encodings comprising a first group of encodings comprising (2.sup.m4) m-bit encodings and a second group of encodings comprising four m-bit encodings, wherein if the selected encoding is an encoding from the first group of encodings then the selected encoding represents the two least significant bits for a representative group of m data values in which the second least significant bit of each of the data values is the same as a respective bit of the m-bit encoding, and wherein if the selected encoding is an encoding from the second group of encodings then the selected encoding represents the two least significant bits for a representative group of m data values in which the two least significant bits for each of the data values in the representative group are equal to the two least significant bits of the other data values in the representative group.

A computer-implemented method for decompressing compressed data, the compressed data representing an n-bit decompressed data value, the compressed data comprising a first compressed subset of bits and a second compressed subset of bits, the first compressed subset representing the n2 most significant bits of the decompressed data value and the second compressed subset representing the two least significant bits of the decompressed data value, the method comprising performing decompression of the first compressed subset using a first decompression module to determine the n2 most significant bits of the decompressed data value; performing decompression of the second compressed subset using a second decompression module to determine the two least significant bits of the decompressed data value, the first and second decompression modules implementing different decompression schemes; and combining the determined n2 most significant bits of the decompressed data value and the determined two least significant bits of the decompressed data value to determine the n-bit decompressed data value.

A computer-implemented method for decompressing compressed data, the compressed data representing an n-bit decompressed data value, the compressed data comprising a first compressed subset of bits and a second compressed subset of bits, the first compressed subset representing the n2 most significant bits of the decompressed data value and the second compressed subset representing the two least significant bits of the decompressed data value, the method comprising performing decompression of the first compressed subset using a first decompression module to determine the n2 most significant bits of the decompressed data value; performing decompression of the second compressed subset using a second decompression module to determine the two least significant bits of the decompressed data value, the first and second decompression modules implementing different decompression schemes; and combining the determined n2 most significant bits of the decompressed data value and the determined two least significant bits of the decompressed data value to determine the n-bit decompressed data value.