BER-Based Estimation of OFDM CFO-Caused Symbol Phase Deviation
Carrier Frequency Offset (CFO) and (high) Peak-to-Average Power Ratio (PAPR) are well-known major drawbacks of the Orthogonal Frequency-Division Multiplexing (OFDM) signal. So, in many practical situations, specifically with LTE-Advanced downlink introducing carrier aggregation, estimation of PAPR and CFO-induced OFDM symbol phase deviation is of interest. However, this demands complex test equipment, such as e.g. Vector Signal Analyzer (VSA), which might not be always and everywhere available. Therefore, we applied the link abstraction principle on the residual BER that is considered to be determined just by the CFO-caused phase deviation, i.e. as if the channel is noiseless and time-dispersion-free (so that evident errors occur just due to actual CFO). Moreover, as recently it has been shown that the phase deviation is linear with the instantaneous (per-OFDM-symbol) PAPR, we develop a simple model for analytical estimating of BER-based CFO, considering the easy-to-measure BER degradation as resulting just from the according additive white Gaussian noise (AWGN) power level, which abstracts the CFO distortion. The proposed analytical model is validated by according Monte-Carlo simulations.