Block time domain channel estimation in OFDM system

摘要

An OFDM receiver receives OFDM symbols in the frequency domain and comb filters and then punctures the OFDM symbols to leave symbols with actual pilot information and with null values at the data symbols. The receiver provides the punctured OFDM symbols to an OFDM symbol queue. A virtual pilot interpolator is coupled to the punctured OFDM symbol storage to generate virtual pilot information introduced to OFDM symbols. The interpolator may be a two dimensional Wiener filter. The receiver also includes a time domain channel estimator that processes a first OFDM symbol including virtual pilot information to generate a channel impulse response for the first OFDM symbol. A frequency equalizer equalizes the OFDM symbol in response to the channel impulse response for the first OFDM symbol.

主权项

1. A method of receiving OFDM signals in an OFDM receiver, the method comprising:
receiving in an OFDM receiver a time domain input signal including at least two consecutive OFDM symbols; transforming the received time domain input signal to a frequency domain signal comprising the at least two consecutive OFDM symbols; interpolating the frequency domain signal comprising the at least two consecutive OFDM symbols to provide an interpolated frequency domain signal based on the at least two consecutive OFDM symbols; transforming the interpolated frequency domain signal to a time domain interpolated signal based on the at least two consecutive OFDM symbols; performing time domain channel estimation using matching pursuit on the time domain interpolated signal based on the at least two consecutive OFDM symbols, the time domain channel estimation comprising matching pursuit iterations including at least one matching pursuit iteration of evaluating a stopping criteria, wherein the stopping criteria measures a ratio within a channel estimation interval and compares the ratio to a threshold value determined for a target signal to noise ratio; and equalizing an OFDM symbol using frequency domain equalization responsive to the time domain channel estimation.