Title :
Interference Cancellation Based Iterative Detection for OFDM Systems over Time-Varying Multipath Channels
Author :
Wang, Xia ; Wang, Lei
Author_Institution :
Sch. of Electron. & Inf. Eng., Xi´´an Jiaotong Univ., Xi´´an, China
Abstract :
For orthogonal frequency-division multiplexing (OFDM) communication systems, the frequency offset caused by time-varying channels induces the loss of orthogonality among subcarriers, and results in Intercarrier Interference (ICI), which seriously degrades the performance of OFDM systems. A novel iterative detection based on parallel interference cancellation is proposed in this paper. The received signal is first processed with MMSE detector, and the decision estimated vector is obtained, then the ICI item can be reconstructed. With the principle of maximize the minimum signal-to-interference and noise power ratio, the strongest interference item will be replaced. The more iterations is carried out, the more the time diversity over time-varying multipath channels will be exploited. Simulation results show that this iterative detector improves the BER performance significantly. When the normalized Doppler frequency offset is comparably large, the BER of the proposed detection can be more improved. Compared with existing ICI mitigation scheme, the proposed scheme has lower computational complexity and better convergence stability.
Keywords :
Doppler shift; OFDM modulation; computational complexity; error statistics; intercarrier interference; interference suppression; iterative methods; least mean squares methods; multipath channels; signal detection; time-varying channels; BER performance; ICI mitigation scheme; MMSE detector; OFDM communication systems; OFDM systems; computational complexity; decision estimated vector; intercarrier interference; iterative detection; minimum signal-to-interference-noise power ratio; normalized Doppler frequency offset; orthogonal frequency-division multiplexing; parallel interference cancellation; received signal detection; time-varying multipath channels; Bit error rate; Computational complexity; Detectors; Doppler effect; Interference; OFDM; Signal to noise ratio;
Conference_Titel :
Wireless Communications, Networking and Mobile Computing (WiCOM), 2011 7th International Conference on
Conference_Location :
Wuhan
Print_ISBN :
978-1-4244-6250-6
DOI :
10.1109/wicom.2011.6040040