Two channel estimators for CP-OQAM-OFDM systems

Due to the insertion of cyclic prefix (CP), orthogonal frequency division multiplexing (OFDM) systems with offset quadrature amplitude modulation (OQAM) (OQAM-OFDM) and CP, denoted as CP-OQAM-OFDM, systems have more robustness to combat a multi-path fading channel and simpler and better receivers than the conventional OQAM-OFDM systems. In this paper, two channel estimators, i.e., weighted least square (WLS) and pairs of pilots (POP) are presented for CP-OQAM-OFDM systems. The WLS estimator requires the insertion of zero symbols to avoid the interference to pilot symbols, and is obtained by minimizing the weighted least square error (WLSE). For the POP estimator, the pilots are designed at the transmitter and determined by the real data symbols. Compared with the WLS estimator, the receiver of the POP is simple, however, the design of pilots of POP requires more computation than that of WLS estimator. Simulation results demonstrate that both of the proposed channel estimators can achieve good bit error rate (BER) performance.