Abstract: A communication unit for performing soft-decision demodulation comprises a receiver that receives a transmitted signal having a first set of bits comprising k bits, selected from a set of 2k possible signals according to values of the k bits, and a second set of bits comprising Qm bits based on a phase rotation of the transmitted signal selected from a set of 2Qm possible rotations. The receiver comprises: a demodulator comprising a bank of 2k correlators and is configured to: detect a transmission of each possible transmitted signal, and output 2k phases of the correlator outputs as a third set of inputs. A de-mapper circuit receives the third set of inputs: determines statistics derived from a number of aggregated correlator output phase distributions of the third set of inputs; and calculates and outputs a second set of aposteriori soft bits comprising Qm soft bits.

Abstract: A communication device comprises a low density parity check, LDPC, rotator circuit comprising sets of registers and configured to have a parallelism, P, of at least two, and to rotate a data sequence of Z data values by R positions, wherein ceil (Z/P) input blocks of P input values is accepted during a first subset of operations, which, before completion, ceil (Z/P) output blocks are provided during a second subset of operations. A padded input block is provided by mod (Z,P) of Z data values and P-mod (Z,P) of padding values when Z is not a multiple of P. The second register set is written with registered values derived before the second subset of operations begins and the values are not overwritten before the padded input block is accepted, and a P output value in an output block is a function of a registered value in the second register set.

Abstract: A communication unit for performing soft-decision demodulation includes a receiver that receives a transmitted signal conveying a first set of bits including k bits selected from a set of 2k possible signals. A demodulator includes a bank of 2k correlators that detects a transmission of each possible transmitted signal, and outputs 2k magnitudes of correlator outputs, based on the detected possible transmitted signals, as a first set of inputs. A de-mapper circuit receives the first set of inputs and determines derived from a plurality of aggregated correlator output magnitude distributions of the first set of inputs, wherein the plurality of aggregated correlator output magnitude distributions is fewer than 22k; and calculates therefrom a first set of aposteriori soft bits including k soft bits. In this manner, high quality soft-decisions can be obtained in a robust and practical manner.

Abstract: A communication device comprises a low density parity check, LDPC, rotator circuit (1000,1300,1500) comprising sets of registers and configured to have a parallelism, P, of at least two, and to rotate a data sequence of Z data values by R positions, wherein ceil(Z/P) input blocks (1014,1310,1507) of P input values is accepted during a first subset of operations, which, before completion, ceil(Z/P) output blocks (1015,1315,1511) are provided during a second subset of operations. A padded input block is provided by mod(Z,P) of Z data values and P-mod(Z,P) of padding values (1220,1401) when Z is not a multiple of P. The second register set is written with registered values derived before the second subset of operations begins and the values are not overwritten before the padded input block is accepted, and a P output value in an output block is a function of a registered value in the second register set.

Abstract: A communication unit for performing soft-decision demodulation comprises a receiver that receives a transmitted signal having a first set of bits comprising k bits, selected from a set of 2k possible signals according to values of the k bits, and a second set of bits comprising Qm bits based on a phase rotation of the transmitted signal selected from a set of 2Qm possible rotations. The receiver comprises: a demodulator comprising a bank of 2k correlators and is configured to: detect a transmission of each possible transmitted signal, and output 2k phases of the correlator outputs as a third set of inputs. A de-mapper circuit receives the third set of inputs: determines statistics derived from a number of aggregated correlator output phase distributions of the third set of inputs; and calculates and outputs a second set of aposteriori soft bits comprising Qm soft bits.

Abstract: A communication unit for performing soft-decision demodulation comprises a receiver that receives a transmitted signal conveying a first set of bits comprising k bits selected from a set of 2k possible signals. A demodulator comprises a bank of 2k correlators that detects a transmission of each possible transmitted signal, and outputs 2k magnitudes of correlator outputs, based on the detected possible transmitted signals, as a first set of inputs. A-de-mapper circuit receives the first set of inputs and determines derived from a plurality of aggregated correlator output magnitude distributions of the first set of inputs, wherein the plurality of aggregated correlator output magnitude distributions is fewer than 22k; and calculates therefrom a first set of aposteriori soft bits comprising k soft bits. In this manner, high quality soft-decisions can be obtained in a robust and practical manner.