Oki Techno Centre (singapore) Pte Ltd

Oki Techno Centre Pte Ltd.

Noriyoshi Ito

Hiroshi Katsuragawa

Tao Zhang

Hiroki Sugimoto

Yu Jing Ting

Zhaocheng Wang

The present invention relates generally to error-correction coding and, more particularly, to a decoder for concatenated codes, e.g., turbo codes. The present invention provides a decoder for decoding encoded data, the decoder comprising: a processor having an input which receives probability estimates for a block of symbols, and which is arranged to calculates probability estimates for said symbols in a next iterative state; normalising means which normalises said next states estimates; a switch that receives both said normalised and said unnormalised next state estimates, the output of the switch being coupled to the input of the processor; wherein the switch is arranged to switch between the normalised and unnormalised next state estimates depending on the iterative state.

Recursive decoder for switching between normalized and non-normalized probability estimates

A pulse density modulator unit transforms an N-bit input signal representing an input value, into an output digital signal having a digital pulse density which is a linear function of the input value. The pulse density modulator unit includes a first pulse density modulator which produces a binary signal representing a multiplication factor as a pulse density. It further includes a combination module which receives the input signal, the binary signal from the first pulse density modulator and an offset control signal. The combination module produces a combined signal which, on average, represents the product of the input signal and the amplification control signal, offset by an amount dependent upon the offset control signal. A second pulse generator uses the combined signal to generate the output digital signal. The combination module may be a selector.

Method and device for pulse density modulation

A code division multiple access (CDMA) receiver for receiving an encoded CDMA signal is disclosed, the receiver comprising an analog to digital converter for sampling a received signal and passing the thus sampled and digitized signal to a CDMA decoder, the converter receiving a sampling clock signal at a sampling frequency, the phase of the clock signal being adjustable. The CDMA decoder includes a plurality of sets of correlators, each set having a different base delay, each base delay being adjustable.

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Hachioji, Japan

Noriyoshi Ito