Chip interleaved cdma2000 with space time block code

Recently, D. Garg and F. Adachi reported that a chip interleaved direct sequence code division multiple access (DS-CDMA) system with a turbo code could improve bit error rate (BER) significantly over a conventional bit interleaved CDMA system under a fading environment (see IEEE 56th Vehicular Technology Conf., p.1777-81, 2002). The use of chip interleaving can transform the fading channel into a highly memoryless or almost additive white Gaussian noise (AWGN) channel. Garg and Adachi studied a single transmit (Tx) and multiple receive (Rx) antenna diversity system under a single user and a frequency nonselective fading environment. We reexamine chip interleaving under (1) multiple users, (2) frequency selective fading, and (3) a space time block code (STBC) system, which is a multiple Tx and Rx antenna element system. Based on simulation results, some conclusions are presented.