Digital receiver

摘要

A digital receiver comprises a quadrature zero intermediate frequency tuner supplying I and Q components to adjustable low pass analog filters. In the case of OFDM signals, a demodulator contains a measuring arrangement which determines the average power of carriers at the band edges and the average power of the OFDM carriers. These are compared and a controller increases the passbands of the filters 7 and 8 until the average level of the edge carrier is substantially equal to the average level of all of the carriers.