A cross-layer design for MIMO Rayleigh fading channels

This paper presents a cross-layer design for packet data transmission over a wireless channel employing transmit diversity. The design combines the use of adaptive modulation (AM) at the physical layer and truncated automatic repeat request protocol (T-ARQ) at the data link layer. The link adaptation process is intended to operate over a multiple-input multiple-output (MIMO) frequency-nonselective Rayleigh fading channel using transmit diversity through space-time block coding (STBC). Two metrics are used to evaluate the performance of the proposed MIMO cross-layer design, namely, the probability of outage and the achievable average spectral efficiency. Results show that this design achieves better performance than adaptive modulation used without ARQ retransmissions in the presence of STBC.