A controller for a solid state drive is proposed. The solid state drive comprises memory cells each one for storing a symbol among a plurality of possible symbols that the memory cell is designed to store. The controller comprises a unit for encoding information bits into encoded bits; a unit for mapping the encoded bits into the symbols, wherein the symbols are determined based on a plurality of allowed symbols, among the possible symbols, that the memory cells are allowed to store, whereas the symbols, among the possible symbols, other than the allowed symbols define forbidden symbols not allowed to be stored in the memory cells; a unit for demapping read symbols and for providing an indication of the reliability of the read symbols based on the forbidden symbols; and a unit for soft decoding the read symbols according to the reliability indication thereby obtaining the information bits.

When a channel between a transmission apparatus and a reception apparatus is distorted by multipath fading or other reasons, linear interpolation between pilot subcarriers produces a large estimation error, resulting in an increase in an equalization error and a decrease in reception performance. The present invention allows feedback of a signal that undergoes error correction, reduction in the channel estimation error through repeated channel estimation, and improvement in the reception performance.

A controller for a solid state drive is proposed. The solid state drive comprises memory cells each one for storing a symbol among a plurality of possible symbols that the memory cell is designed to store. The controller comprises: an encoding unit for encoding information bits into encoded bits; a mapping unit for mapping the encoded bits into said symbols, wherein said symbols are determined based on a plurality of allowed symbols that the memory cells are allowed to store, said plurality of allowed symbols being a subset of the plurality of the possible symbols such that a plurality of forbidden symbols not allowed to be stored in the memory cells are defined among the plurality of the possible symbols, a demapping unit for demapping read symbols and for providing an indication of the reliability of the read symbols based on said plurality of forbidden symbols, and a soft decoding unit for soft decoding the read symbols according to said indication of the reliability of the read symbols thereby obtaining said information bits.

A method for generating soft information for a digital signal decoder. The method includes receiving a first plurality of signals, each corresponding to a time index, each time index being associated with two states including state 1 and state 0. The method also includes processing the first plurality of signals to calculate path metric values of state 0 and 1 for generating each of a second plurality of most-likely symbols by hard decisions and intermediate information for a most-likely path and a second-likely path at each time index. The method includes computing a difference between the most-likely path and a second-likely path for a given one of the two states at each time index. The method also includes determining a soft information corresponding to either one of the two states at the time index per one of the second plurality of most-likely symbols.

A system and a method are disclosed for performing channel estimation in a communication system. The method includes receiving, based on one or more repetitions of a transmitted signal, pilot resource elements (REs); determining at least two sets of partial accumulations of scrambled data REs over the one or more repetitions; generating one or more log-likelihood ratios (LLRs) based on a preliminary channel estimate derived from the pilot REs and the partial accumulations of scrambled data REs; generating a secondary channel estimate based on the one or more LLRs; and decoding data using the secondary channel estimate based on the one or more LLRs.

A method for generating soft information for a digital signal decoder. The method includes receiving a first plurality of signals, each corresponding to a time index, each time index being associated with two states including state 1 and state 0. The method also includes processing the first plurality of signals to calculate path metric values of state 0 and 1 for generating each of a second plurality of most-likely symbols by hard decisions and intermediate information for a most-likely path and a second-likely path at each time index. The method includes computing a difference between the most-likely path and a second-likely path for a given one of the two states at each time index. The method also includes determining a soft information corresponding to either one of the two states at the time index per one of the second plurality of most-likely symbols.