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.