Design of 4 × 4 MIMO-OFDMA receiver with precode codebook search for 3GPP-LTE

In this paper, we propose a VLSI design of a 4 × 4 MIMO-OFDMA down-link baseband receiver for the mobile communications. The receiver consists of synchronization, channel estimation/compensation, precode codebook search, and MIMO detection. To realize the closed-loop MIMO system in the mobile environment, we utilize the MMSE-OSIC algorithm for MIMO detector and capacity selection criterion for precode codebook searcher, in which the Strassen´s algorithm is employed to reduce their matrix inversion and multiplication complexity. The proposed MIMO-OFDMA receiver is designed and evaluated using a standard 90nm CMOS technology. The results show that the receiver achieves 150Mbps data rate and consumes HOmW power at 7.81MHz, which meets the requirement of Mode I~III OFDMA modes for the 3GPP-LTE system.