A Low-Overhead Interference Canceller for High-Mobility STBC-OFDM Systems

Abstract

This paper proposes a low-overhead space-time block code (STBC) interference canceller for high-mobility STBC-orthogonal frequency division multiplexing (STBC-OFDM) systems. The proposed STBC interference canceller combined with the two-stage channel estimator can be applied to wireless metropolitan area network (WMAN), like IEEE 802.16e system. At the vehicle speeds of 240 km/hr for 16 quadrature amplitude modulation (16 QAM), the bit error rate (BER) can be improved about 10 times of that just using the two-stage channel estimator. The proposed design is implemented in 90 nm CMOS technology. The gate count is 109.3 K, and the power dissipation is 1.45 mW at 83.3 MHz operation frequency with 1 V power supply. However, up to 61% hardware can be reused from the existed two-stage channel estimator design. After reusing, the proposed STBC interference canceller requires only 42.2 K gates, which is 4.9% overhead of the two-stage channel estimator.