A signal processor and method of signal processing to reduce delays in channel estimation is described. In the method, the following operations are performed: receiving a signal at a signal processor (200); estimating a first channel from the received signal with a one-dimensional, 1D, frequency filter (304) in a frequency domain to generate an interim output; decoding said interim output (406) to generate decoded interim output; estimating (414,418) at least a second channel from the decoded interim output with a two-dimensional, 2D, filter (100) to produce a final output (420).