• SPECTRAL EFFICIENCY/BIT ERROR RATE OF FQPSK AND OTHER NON-COHERENT SYSTEMS SUPERIOR TO COHERENT SYSTEMS FOR SMS AND BURSTED TDMA AND CDMA SYSTEMS

      McCorduck, James A.; Feher, Kamilo; MatrixSat, Inc.; University of California; Digcom, Inc. (International Foundation for Telemetering, 2002-10)
      For faster acquisition in bursted environments for SMS (Short Messaging Service) and other lower-bit rate applications, non-coherent detection techniques are proposed. Non-Coherent detection demodulators are proposed because faster acquisition capability in bursted environments can result in a reduced amount of preamble bits in the messaging frame, i.e. less overhead, resulting in an effective increase in spectral efficiency. Reducing the preamble can also provide performance enhancement opportunities for Feher Quadrature Phase Shift Keying (FQPSK) [1] and for other systems. The preamble can also be varied to provide for better Bit Error Rate (BER) performance. The lower bit rate environment also gives the opportunity to employ simpler architectures in lieu of preamble modification. Several non-coherent detection alternatives are described.