Modified joint source channel decoder

摘要

A turbo decoder is configured to perform iterative decoding of data bits of a data packet received via a source signal to converge on a “soft” decision representation for each data bit of the data packet. The turbo decoder includes both an interleaved decoder and a non-interleaved decoder that work collaboratively to refine and improve the “soft” decision of each of the originally-received data bits. The interleaved decoder and the non-interleaved decoder are injected with extrinsic information based on at least a-priori information of the source signal. The turbo decoder avoids positive feedback of the a-priori information regarding the source signal from one decoder to the other by subtracting out extrinsic information based on the a-priori information that is injected into a decoder from the “soft” decision(s) determined by the decoder.

主权项

1. A method for iteratively decoding a source signal in a system including a first Maximum A-posteriori Probability (MAP) decoder, a second MAP decoder, and analysis logic, the method comprising:
combining a first extrinsic value provided by the first MAP decoder and a second extrinsic value that is based on a-priori information regarding the source signal to generate a first combined value, the second extrinsic value being provided by the analysis logic; providing the first combined value to the second MAP decoder; and providing a third extrinsic value by the second MAP decoder that is based on at least an interleaved version of one or more data bits of the source signal, one or more first parity bits of the source signal that are derived from the interleaved version of the one or more data bits, and the first combined value.