Patent ID: 6320915
Filing Date: 2001-11-20
Classification: H04L,H04N

Abstract:
Apparatus for processing a signal which comprises a succession of symbol periods T.sub.T at a defined symbol frequency, each symbol period consisting of an active symbol period T.sub.S and a guard interval T.sub.G, the apparatus comprising:an input for receiving an input signal Y;a delay coupled to the input for providing a delayed signal X from the input signal Y, the delayed signal being delayed by a time period equal to the active symbol period T.sub.S ;complex product forming circuitry coupled to the input and the delay for receiving the input signal Y from the input and the delayed signal X from the delay and for forming a complex product which is one of XY* and X*Y, being the product of one of the input signal and the delayed signal, with the complex conjugate of the other of the input signal and the delayed signal and for outputting a complex product signal related to the complex product and comprising a succession of pulses having real and imaginary components, one pulse for each symbol period; anda high-pass filter coupled to the complex product forming circuitry for high-pass filtering the complex product signal to suppress frequencies below the symbol frequency.