Forward error correction with turbo/non-turbo switching

An apparatus comprising:

• a soft-input soft-output (SISO) differential decoder configured to receive as input a forward error corrected and differentially encoded signal received via a communication channel;
• and
• a SISO forward error correction decoder bi-directionally coupled to the SISO differential decoder, wherein the SISO forward error correction decoder is configured to generate a decoder output;
• wherein the SISO differential decoder and the SISO forward error correction decoder are configured to operate in a turbo decoding mode in which soft-decision messages generated by the SISO differential decoder are passed to the SISO forward error correction decoder and forward error correction messages generated by the SISO forward error correction decoder are passed to the SISO differential decoder for a first and initial portion of a plurality of decoding iterations for a given frame, and to operate in a non-turbo decoding mode in which the SISO forward error correction decoder operates without any messages passing to and from the SISO differential decoder for a second and final portion of a the plurality of decoding iterations for the given frame;
• a switch unit configured to couple messages between the SISO differential decoder and the low density parity check decoder in the turbo decoding mode and not coupling messages between the SISO differential decoder and the low density parity check decoder in the non-turbo decoding mode;
• and
• a control unit coupled to the switch unit, wherein the control unit is configured to control the switch unit to switch between the turbo decoding mode and non-turbo decoding mode based on a schedule that is dynamically adjusted on a frame-by-frame basis of the differentially encoded signal.

A non-transitory processor readable storage media encoded with instructions that, when executed by a processor, cause the processor to:

• obtain a forward error corrected and differentially encoded signal received via a communication channel;
• supply the differentially encoded signal to a soft-input soft-output (SISO) differential decoder that is bi-directionally coupled to a SISO forward error correction decoder;
• and
• over a first and initial portion of a plurality of decoding iterations for a given frame of the differentially encoded signal, operate the SISO differential decoder and the SISO forward error correction decoder in a turbo decoding mode in which soft-decision messages generated by the SISO differential decoder are passed to the SISO forward error correction decoder and forward error correction messages generated by the SISO forward error correction decoder are passed to the SISO differential decoder;
• over a second and final portion of the plurality of decoding iterations for the given frame of the differentially encoded signal, operate the SISO differential decoder and the SISO forward error correction decoder in a non-turbo decoding mode in which the SISO forward error correction decoder operates without any messages passing to and from the SISO differential decoder;
• obtain decoder output from the SISO forward error correction decoder;
• and
• switch between the turbo decoding mode and the non-turbo decoding mode based on a schedule that is dynamically adjusted on a frame-by-frame basis of the differentially encoded signal.