US Patent:
20010015995, Aug 23, 2001
Inventors:
David Emery - Charlotte NC, US
Pierre Abbat - Charlotte NC, US
International Classification:
H04B001/69
Abstract:
The present invention provides a system and method for radio communications wherein the transmitted signals include an intermediate frequency in addition to a carrier frequency to aid in demodulation of data modulated on the signals and regulate the local oscillator frequency at the receiver. The invention greatly reduces the number of components required to implement a radio, and in particular, a direct sequence spread spectrum radio, reduces the frequency stability requirement at the transmitting and receiving ends of the communication, automatically tracks changes in the transmission signal after transmission, and permits the use of a single frequency reference to provide all required frequencies to operate both the receiver and the transmitter in each radio.