Duplex radio system utilizing time compression expansion

A duplex radio system having a plurality of terminals each operative for transmitting outgoing signals and receiving incoming signals on any of a plurality of transmission channels which can thus have a used or unused status, each of said plurality of terminals comprising:

• a direct conversion receiver having a receiver input that has the incoming signals coupled thereto during operation in a receive mode, and a receiver output;
• local oscillator means having a control input and an oscillator output and operative for generating and presenting at said oscillator output an output signal at a carrier frequency modulated with any modulating signal supplied to said control input, said oscillator output being coupled to said receiver input to supply thereto at least during operation in said receive mode the output signal of said oscillator means at said carrier frequency;
• compression means for time compressing data, including an output connected to said control input of said oscillator means to supply the time compressed data to said control input as said modulating signal;
• expansion means for time expanding data received, including an input coupled to said receiver output;
• and
• control means having outputs coupled to said compression means and said expansion means to control modulating of said oscillator means with said modulating signal and hence transmission of said time compressed data to be transmitted during a transmit mode of operation, and expansion of said received data during the receive mode of operation.