Decoding order schemes for the layered receiver of multiple space-time codes on the fast flat fading channel

Multiple space-time trellis codes (M-STTC) structure is one of MIMO schemes that provide high transmission rate as well as diversity and coding gain without bandwidth expansion. Receiver structure of M-STTC is composed of decoding order decision block and layered receiver block in which each layer of the receiver consists of whitening processor, STTC decoder, and interference canceller. Since the performance of a layered receiver is influenced by error propagation through layers, the decoding order of each STTC group is important to the overall performance. In this paper, the order decision schemes for flat fast fading channel are proposed. The proposed schemes take into account time varying characteristic of channel over a frame and reliability between STTC groups. The layered receiver employing whitening process with ordering process provides 2 dB gain over that without ordering process on the fast Rayleigh fading channel with f_dT_c = 1/100.