Iterative signal processing. At communication hardware, a signal is received from a transmission medium. The signal has characteristics that obscure data or a signal of interest in the signal. The signal is processed at a first signal processor, which is an iterative processor that performs signal processing in cycles whereby successive cycles: improve the performance of processing of the processor itself over previous cycles, or improve the output from the processor. The signal is processed at one or more second signal processors. Extrinsic data, with respect to the first signal processor is produced as a result. The extrinsic data is provided to the first signal processor and used to counter the effects of the data or signal of interest being obscured in the signal, while the first signal processor is intracycle of a first processing cycle.

In a multi-antenna communication system using LDPC codes, a simple method is used to effectively improve the received quality by performing a retransmittal of less data without restricting applicable LDPC codes. In a case of a non-retransmittal, a multi-antenna transmitting apparatus transmits, from two antennas, LDPC encoded data formed by LDPC encoding blocks. In a case of a retransmittal, the multi-antenna transmitting apparatus uses a transmission method, in which the diversity gain is higher than in the previous transmission, to transmit only a part of the LDPC encoded data as previously transmitted. For example, the only the part of the LDPC encoded data to be re-transmitted is transmitted from the single antenna.

The present technology relates to a data processing apparatus and a data processing method that are able to secure good communication quality in data transmission using an LDPC code. One symbol is mapped to one of 16 signal points prescribed in 16APSK, with code bits of four bits of an LDPC code having a code length of 16200 bits and a code rate of 7/15 as one symbol. 16 signal points prescribed in 16APSK are four signal points on an inner circle and 12 signal points on an outer circle, and a radius ratio of the inner circle and the outer circle is 5.25. The present technology may be applied to, for example, a case of performing data transmission using an LDPC code.

A wireless communication device, including a radiofrequency frontend, configured to wirelessly receive a radiofrequency signal; perform one or more analog baseband operations on the received radiofrequency signal, according to a radio access technology; and output an analog signal representing an output of the analog baseband operations on the received radiofrequency signal; an error corrector, configured to perform an error correction operation on the analog signal; and output an error corrected signal in analog domain; and the analog-digital converter, configured to convert the error corrected signal to digital domain.

An LDPC parity check matrix includes a systematic portion having a plurality of systematic elements and a parity portion having a plurality of parity elements. The value of each systematic element determines a cyclic shift to be applied to rows of an identity submatrix corresponding to that element. The value of each parity element determines a cyclic shift to be applied to rows of an identity submatrix corresponding to that element. The weights of two or more columns of the parity portion are the same.

A low density parity check (LDPC) encoder, an LDPC decoder, and an LDPC encoding method are disclosed. The LDPC encoder includes first memory, second memory, and a processor. The first memory stores an LDPC codeword having a length of 64800 and a code rate of 7/15. The second memory is initialized to 0. The processor generates the LDPC codeword corresponding to information bits by performing accumulation with respect to the second memory using a sequence corresponding to a parity check matrix (PCM).

A low density parity check (LDPC) encoder, an LDPC decoder, and an LDPC encoding method are disclosed. The LDPC encoder includes first memory, second memory, and a processor. The first memory stores an LDPC codeword having a length of 64800 and a code rate of 4/15. The second memory is initialized to 0. The processor generates the LDPC codeword corresponding to information bits by performing accumulation with respect to the second memory using a sequence corresponding to a parity check matrix (PCM).

A transmission device and reception device for digital data that have excellent resistance to noise are provided. An encoder (11-1) of this disclosure, included in a transmission device (1) of this disclosure, applies LDPC encoding to digital data using a unique check matrix for each code rate by using a check matrix in which, taking a check matrix initial value table established in advance for each code rate at a code length of 44880 bits as initial values, 1 entries of a partial matrix corresponding to an information length appropriate for a code rate of 93/120 are allocated in the column direction over a cycle of 374 columns. A demodulator (23) of this disclosure, included in a reception device (2) of this disclosure, decodes digital data encoded by the encoder (11-1).

A transmitting apparatus and a receiving apparatus are provided. The transmitting apparatus includes: an encoder configured to generate a low density parity check (LDPC) codeword by performing LDPC encoding; an interleaver configured to interleave the LDPC codeword; and a modulator configured to modulate the interleaved LDPC codeword according to a modulation method to generate a modulation symbol. The interleaver includes a block interleaver formed of a plurality of columns each comprising a plurality of rows, and the block interleaver is configured to divide the plurality of columns into at least two parts and interleave the LDPC codeword.

In a multi-antenna communication system using LDPC codes, a simple method is used to effectively improve the received quality by performing a retransmittal of less data without restricting applicable LDPC codes. In a case of a non-retransmittal, a multi-antenna transmitting apparatus (100) transmits, from two antennas (114A,114B), LDPC encoded data formed by LDPC encoding blocks (102A,102B). In a case of a retransmittal, the multi-antenna transmitting apparatus (100) uses a transmission method, in which the diversity gain is higher than in the previous transmission, to transmit only a part of the LDPC encoded data as previously transmitted. For example, the only the part of the LDPC encoded data to be re-transmitted is transmitted from the single antenna (114A).