Topcon Positioning Systems, Inc.

Dmitry A Pyatkov

Timur G Kelin

Dmitry D Murzinov

Nikolay Afanasievich Vazhenin

A multi-channel sequential Viterbi decoder includes: an input buffer, a 'Read Data from Input Buffer' signal driver, a processing unit selector, a decoder channel parameters registers unit, a processing unit for a 'Reset Path Metrics' command, a processing unit for a &#x201c;Set Path Metric Value for the Given Path Number&#x201d; command, a processing unit for a &#x201c;Get Single Bit from the Path with Given Number&#x201d; command, a processing unit for a &#x201c;Process Input Samples&#x201d; command, a memory for storing decoding paths and path metrics, a unit for generating an address for the memory, and data buffers for decoder channels output.

Multi-channel sequential Viterbi decoder

A method of estimating signal-to-noise ratio in a Viterbi decoder comprising: setting a threshold SNR value; determining a dependence on SNR of the average decoding path length; filling branch metrics matrix, minimal path metrics matrix, path metrics matrix and paths matrix with initial values; receiving packets from a communication channel; calculating the matrices that contains paths stored during operation of Viterbi algorithm in its rows, and a minimal path metrics matrix, including calculating an estimate of a decoding path length, where all the paths converge, based on the paths matrix; calculating current SNR estimate using an estimate of a decoding path length, based on results of previous steps; setting a decoder control signal to an active state if the current estimated SNR does not exceed the threshold, and to an inactive state otherwise; if the decoder control signal is in active state, the branch metrics matrix, the minimal path metrics matrix, the paths metrics matrix and the paths matrix are filled with the initial values; generating a decoded symbol; and repeating the steps on a next packet if one is available.

Method and apparatus for signal-to-noise ratio estimation in convolutional codes (Viterbi) decoder

A multi-channel sequential Viterbi decoder includes: an input data buffer, a 'Read Single Data Word from Input Data Buffer' signal driver, a processing unit selector, a decoder channel parameters registers unit, a processing unit for the 'Reset Path Metrics' command, a processing unit for the &#x201c;Set Path Metric Value for the Given Path Number&#x201d; command, a processing unit for the &#x201c;Get Single Bit from the Path with Given Number&#x201d; command, a processing unit for the &#x201c;Process Input Samples&#x201d; command, a decoding paths and path metrics RAM, a unit for generating current decoder channel base address for the decoding paths and path metrics RAM, a unit for generating cell address for the decoding path and path metric RAM, and a data buffers unit for decoder channels output.

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Moscow, Russia

Dmitry A Pyatkov