NSF Award
9901866
This Small Business Innovation Research Phase II project implements flexible hardware and software devices of a class of combined modulation and coding techniques called Turbo Product Coded Modulation (TPCM) that significantly outperforms the current techniques in digital communications systems, with regard to achieving high bits per Hz modulation at a low signal to noise ratio. Efficient Channel Coding (ECC) will also investigate enhancements to the TPCM decoding algorithms as well as applications in other modulated channels. The hardware devices will be based on an existing application specific integrated circuit (ASIC) product that contains the decoding engine for TPCM, and the software devices will be based on existing digital signal processor (DSP) devices. The result of the research will be practical TPCM prototype products that provide enhancement performance over existing techniques. For example, one TPCM scheme as applied to 32-ary Quadrature Amplitude Modulation (QAM) offers performance within 0.65 dB of the theoretical limit for this modulation scheme.<br/> Flexible TPCM systems are useful in a wide range of digital communications system in which power and bandwidth are limited resources. These include ECC is targeting TPCM insertion into the next generation satellite communications modems, Direct Broadcast Satellite, and other future satellite communications systems as well as emerging terrestrial systems. These terrestrial systems include Wireless Local Area Networks, Digital Radio, Digital Television, Local Multipoint Distribution Systems, IMT-2000, and Digital Subscriber Links.
