Flexible, Adaptive, and Practical Bandwidth-Efficient Waveform Design

Current SATCOM systems provide far from the best possible theoretical bandwidth-efficiency.  Techniques have recently emerged that provide point solutions allowing very efficient performance.  However, with these approaches, little attention is usually paid to the implementation complexity or the impact of system impairments and nonlinearities.  Furthermore, the waveform rate needs to be flexible and adaptive to allow operation in rapidly time-varying channels (e.g., with On-The-Move (OTM) systems) and across a wide range of terminal types.  To satisfy SATCOM requirements, ORB Analytics, LLC, proposes an LDPC coded system that operates with modulation chosen from CPM and MQAM/OFDM depending upon the terminal capabilities, service requirements, and operating scenarios.  The proposed Phase I effort would investigate design methods that provide the required flexibility and adaptability by careful design of the interface between the demodulator and decoder, the choice of specific LDPC code and modulation, and the incorporation of impairment compensation methods. BENEFIT: Given the overall scarcity of spectrum and increasing communications demands, the need for bandwidth-efficient waveforms extends across a wide range of military and commercial applications.  ORB Analytics, LLC, believes a successful demonstration of the proposed bandwidth-efficient waveform could lead to its use in future military SATCOM and terrestrial communications systems as well as commercial communications systems including cellular, wireless local area network, and wireless personal area network systems.  Further the flexibility and adaptability inherent in the proposed design makes it suitable for military and commercial cognitive radio initiatives including wireless regional area networks.