A wireless local area network (WLAN) transmitter includes a baseband processing module and a plurality of radio frequency (RF) transmitters. The processing module selects one of a plurality of modes of operation based on a mode selection signal. The processing module determines a number of transmit streams based on the mode selection signal. The processing of the data further continues by converting encoded data into streams of symbols in accordance with the number of transmit streams and the mode selection signal. A number of the plurality of RF transmitters are enabled based on the mode selection signal to convert a corresponding one of the streams of symbols into a corresponding RF signal such that a corresponding number of RF signals is produced.

Channel encoding is provided that includes applying turbo coding with a coding rate of 1/5 to an input bit sequence, applying a subblock interleaver to each of first to fifth code bit sequences to which the turbo coding is applied, applying bit collection to the first to fifth code bit sequences output from the subblock interleaver, the bit collection outputting the first code bit sequence in order, outputting the second code bit sequence and the fourth code bit sequence alternately on a bit-by-bit basis after the first code bit sequence, and outputting the second code bit sequence and the fifth code bit sequence alternately on a bit-by-bit basis.

Systems and methods are disclosed for providing H-ARQ transmissions in respect of a set of horizontal code blocks are combined in a code. Retransmissions contain vertical parity check blocks which are determined from verticals from the set of horizontal code blocks. Once all the vertical parity check blocks have been transmitted, a new set may be determined after performing interleaving upon either the content of the horizontal code blocks, in the case of non-systematic horizontal code blocks, or over the content of encoder input bits in the place of systematic horizontal code blocks. The interleaving may be bitwise or bit subset-wise. The retransmissions do not contain any of the original bits. In the decoder, soft decisions are produced, and nothing needs to be discarded; decoding will typically improve with each retransmission.

A method for generating a signal, including turbo-coding a set of information symbols delivering, on the one hand, the information symbols and, on the other hand, redundancy symbols. The turbo-coding implementing, to obtain the redundancy symbols: an encoding of the set of information symbols by a first encoder, an interleaving of the set of information symbols, and an encoding of the set of information symbols interleaved by a second encoder. The turbo-coding also implements a bijective transformation of the information symbols, implemented before and/or after the interleaving, the transformation modifying a value of at least two of the information symbols prior to the coding of the information symbols by the first and/or the second coder.

The present disclosure includes apparatuses and methods for error rate reduction. One example method comprises adding an amount of error rate reduction (ERR) data to an amount of received user data, and writing the amount of user data along with the amount of ERR data to a memory.

Coding techniques for a (e.g., OFDM) communication system capable of transmitting data on a number of “transmission channels” at different information bit rates based on the channels' achieved SNR. A base code is used in combination with common or variable puncturing to achieve different coding rates required by the transmission channels. The data (i.e., information bits) for a data transmission is encoded with the base code, and the coded bits for each channel (or group of channels with the similar transmission capabilities) are punctured to achieve the required coding rate. The coded bits may be interleaved (e.g., to combat fading and remove correlation between coded bits in each modulation symbol) prior to puncturing. The unpunctured coded bits are grouped into non-binary symbols and mapped to modulation symbols (e.g., using Gray mapping). The modulation symbol may be “pre-conditioned” and prior to transmission.

A decoding module for a communication device includes a first calculation circuit, outputting the larger between a first parameter and a second parameter as a first output parameter; a first arithmetic circuit, calculating a first product of a third parameter and a first slope, and a first difference between a first constant and the first product; a second arithmetic circuit, calculating a second product of the third parameter and a second slope, and a second difference between a second constant and the second product; a second calculation circuit, selecting the largest among a third constant, the first difference and the second difference and generating a second output parameter, wherein the third constant is zero; and an addition circuit, adding the first output parameter and the second output parameter to generate output information, according to which the communication device determines a data bit.

A system and method for transmitting high speed data on fixed rate and for variable rate channels. The system and method provides the flexibility of adjusting the data rate, the coding rate, and the nature of individual retransmissions. Further, the system and method supports partial soft combining of retransmitted data with previously transmitted data, supports parity bit selection for successive retransmissions, and supports various combinations of data rate variations, coding rate variations, and partial data transmissions.

A packet processing method and device are disclosed. The method includes: performing code block segmentation on a source packet to obtain a sub-packets; performing error correction encoding on each sub-packet respectively, or performing error correction encoding after respectively adding a CRC sequence to each sub-packet to obtain a error correction encoding sub-packets; performing network encoding on the a error correction encoding sub-packet to obtain b check sub-packets; and performing bit selection operation on the a error correction encoding sub-packets and the b check sub-packets respectively to collectively form an encoded packet; herein a and b are integers greater than 0.

Provided is an optical transmission device including: a symbol demapping unit; a likelihood generation circuit configured to generate likelihoods relating to the reception signal; and an error correction decoding unit configured to execute soft decision decoding. The likelihood generation circuit includes: a first one-dimensional-modulation lookup table configured to input the signal of the I-axis component as an argument to output a first likelihood; a second one-dimensional-modulation lookup table configured to input the signal of the Q-axis component as an argument to output a second likelihood; and a two-dimensional-modulation lookup table configured to input, as an argument, the signal being the concatenation of the signal of the I-axis component and the signal of the Q-axis component, to generate a third likelihood. The error correction decoding unit is configured to execute the soft decision decoding based on the first likelihood, the second likelihood, and the third likelihood.