Abstract: The diversity gain is always maximized first before coding gains are optimized in the design of a space-time coding system. The similar method is always adopted in designing the serially concatenate space-time coding system(SCST). A new optimization method for the optimization of SCST via matching the inner and outer encoder is presented. The effect of outer code redundancies on the performance of SCST is analyzed carefully. It is also pointed out that the matches between the inner and outer encoder can be acquired via the permutation of the interleaver on the outputs of the outer encoder. The work in this paper also provides the possibility to decrease the system complexity further. The siumlation results show that the matched SCST system obtains approximately 2dB gains compared with those SCSTs with available STTC in other contributions.

Key words: weigh distribution, space-time trellis codes, serially concatenated systems, matching