Joint estimation of CFO and receiver I/Q imbalance using virtual subcarriers for OFDM systems

Abstract

Abstract-In this paper, we study the estimation of carrier frequency offset (CFO) in the presence of the receiver in-phase and quadrature-phase (I/Q) imbalance for orthogonal frequency division multiplexing (OFDM) systems. By minimizing the energy of the samples on the virtual subcarriers, our proposed algorithm can jointly estimate the CFO and I/Q parameters using one OFDM block. When the CFO is small, a closed-form solution can be obtained. Simulation results show that our proposed method can provide a good performance for both of the I/Q and CFO estimation and it compares favorably with a recent method.

Timing and carrier synchronization in wireless communication systems: a survey and classification of research in the last 5 years

“…The first group of papers does not provide an estimation error lower bound [78,82,86,92,94,99,113,114,115,117,128,137,157,188]. In addition to carrier synchronization, the CFO estimation algorithm proposed by [78] is valid even if timing offset and channel length is unknown, the algorithm proposed by [82] estimates integer frequency offset, the algorithm proposed by [86] estimates sampling frequency offset in addition to CFO, [92] estimates IFO for OFDM-based digital radio mondiale plus system, [94] considers IQ imbalance and directconversion receivers, [99] considers CFO tracking in digital video broadcasting (DVB-T) system, [113] proposes ML based estimation, [114] and [117] propose IFO estimation with cell sector identity detection in long term evolution systems, [115] considers IQ imbalance and hardware implementation, [128] also considers SFO estimation, [137] proposes ML based estimation and considers the design of pilot pattern, the estimation algorithm in [157] is robust to the presence of Doppler shift and [188] considers IQ imbalance and its estimation. The second group of papers provides an error lower bound on CFO estimation [83,84,91,101,102,104,132,136,138,160,163,…”

“…sel. Yes Yes Pilot Est CFO Yes [81], [87], [97], [116], [118], [165] Freq [82], [86], [92], [94], [99], [113], [114], [115], [117], [128], [137], [157], [188] Freq. sel.…”