On Some Thedretical Considerations for RF Transmission of Quadraphonic Sound

Present proposed FM quadraphonic transmission systems are shown to be narrow-band FM schemes. Hence, the FM noise improvement properties of mono-FM transmission are not realizable. On theoretical grounds, it is shown that 1) there exists a compatible quadraphonic scheme that preserves the wide-band FM properties of stereophonic FM, 2) allows two additional channels of information to be impressed upon the carrier, and 3) offers a 4.7 db improvement in quadraphonic transmission as compared to the presently pro-proposed FM quadraphonic schemes.