Coding theory: Difference between revisions

Revision as of 18:59, 9 March 2006

Revision as of 16:50, 13 April 2006

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Convolutional codes are used in voiceband modems (V.32, V.17, V.34) and in GSM mobile phones, as well as satellite and military communication devices.

Here the idea is to make every codeword symbol, be the weighted sum of the various, input message symbols. This is like [[convolution]] used in [[linear time invariant|LTI]] systems to find the output of a system, when you know the input and impulse response.

So we generally find the output of the system [convolutional encoder] , which is the convolution of the input bit, against the states of the convolution encoder, registers.