| 摘要 |
A method and apparatus for estimating the signal to noise ratio of a broadcast Orthogonal Frequency Division Multiplex (OFDM) signal is described. Received signals of the data in a guard interval and the corresponding part of the data frame of an OFDM symbol, which were identical when transmitted but which may differ when received due to noise in the channel, are compared. A sum and difference operation is then performed on the data in the compared signals to enable a Signal-to-Noise Ratio to be estimated. Sliding correlation to identify a peak and phase correction are also involved. The OFDM signal may be a DAB (Digital Audio Broadcasting) ensemble. The SNR estimation method described may be performed quickly using only two symbols worth of data and without the receiver having to lock on to the OFDM signal. |
