Oki Techno Centre (singapore) Pte Ltd

Chang Qing Xu

Ju Yan Pan

Hiroshi Katsuragawa

Masayuki Tomisawa

An encoder system for encoding a signal according to any number of FEC and/or channel codes comprises a shift register, an array of MOD/XOR stages, and a generator matrix stage for controlling the connections between the shift register and the MOD/XOR stages and altering these connections according to a coding format selected by an encoder selection stage. There is also disclosed a decoder system for decoding a signal encoded according to a number of FEC and/or channel codes comprising a decoding stage, and a generator matrix stage for configuring the decoding stage to a decoding code format to be applied an incoming encoded signal. A decoder selection stage is coupled to the generator matrix stage and selects the decoding code format to be used in the decoding process. The decoder selection stage instructs the generator matrix stage to configure the decoding stage according to the selected decoding code format. There is also disclosed a method for encoding and decoding.

Encoder system, a decoder system, a coding/decoding apparatus, an encoding method and a decoding method

A communications system employs a HARQ method and, for at least some transmission formats, incremental redundancy (IR) signals. For such formats, the multiple IR signals are derived from a single turbo encoded signal by forming multiple permutations of the encoded signal. The permutations are then converted to the coding rate of the selected transmission format. It is demonstrated by simulation that the present proposal achieves a better performance than the known HARQ techniques, while its implementation is simpler. For certain transmission formats, the transmitted signal in response to a retransmission request is identical to the first transmitted signal.

Communication system employing turbo codes and a hybrid automatic repeat request scheme

A method of estimating the reliability of decoded message bits in a digital communications system is proposed. Message and tail bits are coded and transmitted across a communications channel. The coded message and tail bits are then decoded and it is determined that the decoded message bits have no error when the decoded tail bits have at least one error.

Method of estimating reliability of decoded message bits

Multipath interference in a received wireless signal is cancelled by generating an estimated duplicate of the interference and subtracting it from the received signal. The interference duplication is performed in a truncated manner, based on a determination of which multipath signals are present, so as to reduce the complexity and processing requirement of the interference duplication. In particular, the present invention proposed that the truncation is based on a determination of which multipath signals are present, and the properties of those signals. In a first case, the truncation is that only interference between selected pairs of paths are cancelled in MPIC. In a second case, for given pairs of paths cancellation is only performed for a subset of the chips in which the corresponding two paths can cause interference.

Reduced-complexity multipath interference cancellation

A receiver for a HARQ communication system includes a buffer for storing a signal derived from a message. The signal is transmitted to the receiver at a first coding rate. The receiver also includes a decoder which accepts signals having a second coding rate, and a rate dematcher which converts signals from the first coding rate to the second coding rate. The rate dematcher is arranged to process either a combination of the received signals (in the case that the received signals are noisy versions of identical signals transmitted within the communications network) or simply the set of received signals. In either case, the dematcher forwards the results to the decoder. Provided that the second coding rate is lower than the first coding rate, the amount of memory required by the buffer is reduced by locating the buffer before the rate dematching unit.

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Singapore, Singapore

Chang Qing Xu