| 摘要 |
A receiver circuit is for processing a received signal which includes at least a first portion and a second portion which repeats the content of the first portion after a repeat interval. For example, the receiver may be for DVB-T signals using COFDM. In order to ensure that the estimated symbol start position is accurate, the receiver calculates two correlation values, namely an early correlation and a late correlation. The early correlation is measured between samples ahead of an assumed first portion start position and ahead of an assumed second portion start position, and the late correlation is measured between samples behind an assumed first portion end position and behind an assumed second portion end position. When the assumed start and end positions are accurate, the early and late correlations are equal, and so the assumed start and end positions are controlled to equalize the early correlation and the late correlation. The receiver includes a sampler 10, delays 14,16, correlational combiners 18,32, a subtractor 30 and a loop filter 44. The receiver may be a TV receiver. |
