On the Markovian approximation for block-errors in DS-CDMA transmissions over slow fading channels with multicarrier transmit diversity

We show that block errors in multicarrier DS-CDMA (MC-CDMA) systems with transmit diversity operating over slow fading channels are accurately modeled by a Markov process. Although earlier contributions have shown that packet transmission over radio channels can be modeled by Markov processes, error models for DS-CDMA systems using multicarrier transmit diversity, convolutional coding with soft-decision Viterbi decoding, and RAKE diversity fingers with maximal ratio combining, have not been reported so far. A major contribution of this work is a novel method to estimate the parameters of the Markov model. Comparisons with results of detailed simulations of the entire system confirm that this is an excellent packet-level error model for MC-CDMA with transmit diversity.