Joint adaptive rate turbo decoding and synchronization on Rayleigh fading channels

We present a modification of a typical turbo code allowing for adaptive changing of the code rate and signal synchronization properties. The proposed algorithm inserts pilot symbols into the code structure and frequently terminates the first trellis of the turbo encoder by inserting tail bits into the data sequence. By changing the length of the number of bits between the termination of the trellis, the rate of the code can be almost arbitrarily changed. Moreover such an approach allows for: constant interleaver length, simpler decoder and improved channel estimation using the properties of turbo codes. We show that the performance of the proposed system is better than the performance of the systems using typical pilot synchronization.