Using SISO decoder feedback to produce symbol probabilities for use in wireless communications that utilize single encoder turbo coding and transmit diversity
AssigneeTexas Instruments Incorporated
InventorsAlan Gatherer, Tarik Muharemovic, Everest W. Huang, Srinath Hosur
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Abstract
An apparatus and method for transmitting and receiving a bit stream. On the transmission side, coded bits (Y.sub.t) and an interleaved version of the coded bits (X.sub.t) are separately modulated and transmitted. On the reception side, a priori output probabilities produced by a probability generator (34) are combined (112) and then input to a SISO decoder (111). Combined a posteriori output probabilities (115) produced by the SISO decoder are split (113) and then fed back to the probability generator.
Claims17
A wireless communication receiving apparatus, comprising:
- an antenna for receiving via first and second wireless communication channels a composite communication symbol that represents first and second communication symbols which each correspond to a result of a coding operation performed by a transmitter apparatus on a bit stream;
- a probability generator coupled to said antenna and responsive to said composite communication symbol for generating, for said first and second communication symbols, corresponding first and second pluralities of probabilities that the communication symbol has respective ones of a plurality of possible values of the communication symbol;
- a combiner coupled to said probability generator for combining said first and second pluralities of probabilities to produce a plurality of combined probabilities;
- a SISO decoder corresponding to said coding operation and coupled to said combiner for receiving the plurality of combined probabilities and producing therefrom a further plurality of combined probabilities;
- a splitter coupled between said SISO decoder and said probability generator for receiving said further plurality of combined probabilities and producing therefrom third and fourth pluralities of probabilities that respectively correspond to said first and second communication symbols;
- and
- said probability generator operable for generating said first and second pluralities of probabilities also in response to said fourth and third pluralities of probabilities, respectively.
A method of wireless communication, comprising:
- receiving via first and second wireless communication channels a composite communication symbol that represents first and second communication symbols which each correspond to a result of a coding operation performed by a transmitter apparatus on a bit stream;
- for said first and second communication symbols, and responsive to the composite communication symbol, generating corresponding first and second pluralities of probabilities that the communication symbol has respective ones of a plurality of possible values of the communication symbol;
- combining the first and second pluralities of probabilities to produce a plurality of combined probabilities;
- applying the plurality of combined probabilities to a SISO decoder that corresponds to said coding operation;
- the SISO decoder producing from the plurality of combined probabilities a further plurality of combined probabilities;
- splitting the further plurality of combined probabilities into third and fourth pluralities of probabilities that respectively correspond to the first and second communication symbols;
- and
- said generating step including generating the first and second pluralities of probabilities also in response to said fourth and third pluralities of probabilities, respectively.
Dependencies are inferred from the claim text.