AF TOPIC NUMBER: AF00-120 Circular Trellis Coding for Wavelet Packet Modulation Digital Communications

The primary goal of the work to be accomplished under this SBIR Phase II effort is the implementation of an efficient and reliable wireless Circular Trellis Coded Wavelet Packet Modulation System (CTCWPMS). The developed prototype CTCWPMS will moreeffectively address a variety of wireless communications challenges that cannot be met using conventional Fourier source and channel coding methods. Multi-Carrier Modulation (MCM) techniques are being increasingly employed in military communicationnetworks to combat time-dispersive and time-variant channel effects. One MCM method, Coded Orthogonal Frequency Division Multiplexing, has been particularly effective against multipath fading environments. CTCWPM, however, is a far more potentcoding/modulation combination that affords superior signal protection in combined narrowband jamming and impulsive-interference situations. CTC is a robust error coding technique that synergistically bonds well with WPM's multidimensional orthogonalsignaling. In such high dimensional signaling environments, CTC is very competitive with turbo codes, providing similar bit error rate performance while being non-iterative. WPM's strength rests in a flexible, custom mapping of the designed signal on thecommunications channel at the transmitter to avoid a variety of apriori noise/interference patterns. SRC has found a feasible receiver symbol timing recovery algorithm for CTCWPMS implementation that will help expedite the adoption of this waveform's useon wireless channels. The prototype CTCWPMS will emphasize the use of reconfigurable hardware, enabling a migration path for the waveform's incorporation in other applications including wireless LANs, 3G & 4G data services, Future Combat System (FCS),expendable data links and software radios such as the Joint Tactical Radio System (JTRS).