EVM与误码率分析.pdf

Ann. Telecommun. (2009) 64:753–762 DOI 10.1007/s12243-009-0116-z Analytical EVM, BER, and TD performances of the OFDM systems in the presence of jointly nonlinear distortion and IQ imbalance Hassan Zareian Vahid Tabataba Vakili Received: 14 September 2008 /Accepted: 5 May 2009 /Published online: 27 May 2009 # Institut TELECOM and Springer-Verlag France 2009 Abstract The orthogonal frequency-division multiplexing audio broadcasting, and wide-band wireless communica- (OFDM) systems are highly sensitive to the nonlinear tion systems [ 1]. However, due to a greatly variable distortions introduced by the high-power amplifier at the envelope or high peak-to-average power ratio, a major transmitter and to the in-phase and quadrature (IQ) impairment for the OFDM systems, especially in broad- imbalance of the down converter at the receiver. In this casting applications, is the presence of a nonlinear high- paper, the joint effects of these impairments on the power amplifier (HPA) at the transmitter, which introduces performance of the OFDM systems with M signal points nonlinear distortion [2]. The high sensitivity to in-phase quadrature amplitude modulation (M-QAM) are investigated. and quadrature (IQ) imbalance is also another serious Moreover, the analytical formulations for the error vector source of impairment [3]. magnitude, the bit error rate, and the total degradation The aim of this paper is to analytically study the performances of the M-QAM-OFDM systems in additive performance of OFDM systems by jointly taking into white Gaussian noise channels as a function of the output account the IQ imbalance and nonlinear distortion in back off and IQ imbalance parameter