Abstract：In this paper, a cross-layer design in OFDM (Orthogonal Frequency Division Multiplexing) systems with a space-time coded transmit diversity is provided, which combines the use of AM (Adaptive Modulation) at the physical layer and ARQ (Automatic Repeat reQuest protocol) at the data link layer. The packet error rate and channel estimation are used to compute the adaptive threshold in order to maximize spectral efficiency under given delay and error performance constraints. Simulation results show that this cross-layer design has 1.5dB gain in spectral efficiency comparing the traditional adaptive transaction at physical layer. Nevertheless, with the increasing of maximum number of retransmissions, the gain in spectral efficiency decreases, which suggest that enough spectral efficiency gain can be gotten by a desirable delay in practical systems.
衡伟; 冀晓亮. MIMO OFDM系统中基于物理层与链路层的跨层优化设计[J]. 电子与信息学报, 2008, 30(5): 1261-1263 .
Heng Wei;Ji Xiao-liang . A Cross-layer Design on Physical Layer and Data Link Layer in MIMO OFDM System. , 2008, 30(5): 1261-1263 .
2008, Vol. 30 
