Transceiver signal processor for digital cordless communication apparatus

Claim 1

A transceiver signal processor for a digital cordless communication apparatus having a transmitter for converting an electrical signal into a radio wave and transmitting said radio wave via an antenna, and a receiver for converting a radio wave received from said antenna into a received electrical signal and processing the received signal, in a communication system using a time-division method by which a frequency channel is divided into constant time intervals for alternating transmission and reception modes of operation, said processor comprising: a frequency synthesizer including a first phase-locked loop (PLL) for channel conversion by which the loop frequency of said first PLL is kept constant by setting an offset corresponding to a received second intermediate frequency to 0 Hz, and a second PLL for high-speed switching between transmit and receive frequencies, by setting the output frequency of said first PLL as a reference signal for said second PLL.