Blind frequency offset/symbol timing/symbol period estimation and subcarrier recovery for ofmd signals in fading channels

摘要

This paper procses a fully-blind frequency offset, symbol timing and symbol period estimator for OFDM signals in fading channels. In OFDM system, each symbol is extended with a guard interval, which is the tail of the signal itself, therefore, we can deal with it as "an unknown pilot signal.? The estimation method is based on the maximum likelihood criterion, making effedctive use of the unknown pilot signal. This paper also proposes a blind subcarrier recover method which calculates frequency transfer function essential for subcarrier recover from the correlation matix of the unknown pilot signals.