A novel fading cancellation scheme for trellis coded systems based on a multichannel approach

The system encodes the information between signals suffering from similar fading signatures. Through proper processing, the fading signatures cancel each other from the final output. With the exception of the fading-cancellation capabilities, the system is also able to eliminate the Doppler phase shifts associated with the moving nature of the communication units. The scheme has been evaluated for a trellis coded four-phase-shift-keying (PSK) system. The results demonstrated improvements on the order of 9.0 dB at a bit error rate (BER) of 10^-3 and reduction of error floors greater than three orders of magnitude. These improvements have been achieved without the use of interleaving, necessary for the operation of trellis-coded schemes under fading conditions. By eliminating the interleaving, extra complexity, as well as long time delays with negative effect on the quality of the communication link, is avoided