Patent ID: 7609614
Filing Date: 2009-10-27
Classification: H04L

Abstract:
1. A demodulator apparatus for use in a wireless multiple-access communication system where a headend communicates with a plurality of wireless subscriber stations, and the plurality of wireless subscriber stations use frequency division multiplexing to share an uplink frequency bandwidth, the demodulator apparatus comprising: a channelizing filter bank that separates a collection of frequency division multiplexed uplink signals into a plurality of noncoherently demodulated channel signals including a particular noncoherently demodulated channel signal, wherein the noncoherently demodulated channel signals are noncoherently demodulated complex-valued channel signals and the particular noncoherently demodulated channel signal is a particular noncoherently demodulated complex-valued channel signal; a noncoherent detector configured to detect information from the particular noncoherently demodulated channel signal, the noncoherent detector including an I/Q demodulator that noncoherently extracts first and second real-valued baseband signals respectively from an in-phase carrier signal and a quadrature-phase carrier signal, and the particular noncoherently demodulated complex-valued channel signal comprises the first and second real-valued baseband signals; and a trellis decoder responsive to the particular noncoherently demodulated complex-valued channel signal, wherein the trellis decoder includes: wherein the particular noncoherently demodulated complex-valued channel signal corresponds to a quadrature-multiplexed continuous phase modulation (QM-CPM) signal, and the first and second real-valued message signals are related to respective first and second continuous-phase baseband signals though a complex-to-real mapping function.