Chip-by-chip turbo coding for DS/SS systems

Most of error correcting codes applying to DS/SS systems are such that info rmation data is first (bit-by-bit) encoded and then spread by pseudo noise (PN) sequence. Thus, coding; gain achieved by such systems are mainly due t o the error correcting codes and the redundancy produced by the spreading c odes shows no effect on the coding gain. In this paper, a chip-by-chip Turb o coding for DS/SS systems is proposed. The input information data is first spread by PN sequence and then fed into the Turbo-encoder which operates i n chip timing. As the Turbo-encoder operates in chip timing, a large interl eaving size would be obtained, which improves the performance. As results, superior performances with coding gain of more than 3.0 dB and 5.0 dB for A WGN and Rayleigh-fading channel, respectively, were found with short frame size of information data.