Patent ID: 6421403
Filing Date: 2002-07-16
Classification: H03D,H04L

Abstract:
A radio receiver for digital transmissions, said radio receiver comprising:a local oscillator for supplying local oscillations the frequency and phase of which are controlled by an automatic frequency and phase control signal; a mixer for downconverting received digital transmissions by heterodyning them with said local oscillations to generate an intermediate-frequency signal; synchrodyne circuitry for demodulating said intermediate-frequency signal to generate an in-phase baseband demodulation result and to generate a quadrature-phase baseband demodulation result; equalization-and-ghost-cancellation-filtering circuitry having filtering parameters that are adjustable, for processing said in-phase baseband demodulation result to generate a first equalization-and-ghost-cancellation-filter response and for similarly processing said quadrature-phase baseband demodulation result to generate a second equalization-and-ghost-cancellation-filter response; apparatus for adjusting the filtering parameters of said equalization-and-ghost-cancellation-filtering circuitry in response to portions of said in-phase baseband demodulation result; a symbol decoder for decoding symbols in said first equalization-and-ghost-cancellation-filter response, thereby to recover data encoded in those said symbols; and circuitry for generating said automatic frequency and phase control signal by lowpass filtering said second equalization-and-ghost-cancellation-filter response.