Variable and Adaptive Coded Modulation for Cognitive Networking, Year 2

Variable coded modulation (VCM) and adaptive coded modulation (ACM)has the following benefits: 1. Double a typical NASA mission's total downlink data volume, without increasing required power or bandwidth, by making more efficient use of time-varying resources. This meets NASA's strategic goals of more power and spectral-efficient technology. 2. Enable communication through launch plumes and through plasma during Earth reentry, and in other unpredictable, highly dynamic link conditions. VCM technology is cross-cutting, in the sense that once developed and standardized, every new mission will be able to take advantage of its benefits of increased data return. Thus, unfunded/planned missions will benefit in the same way as funded missions with this technology. NOAA and DoD space missions could make use of the VCM/ACM technology and achieve the same benefits as NASA. Since all or nearly all of these space missions are near-Earth, they are particularly subject to dynamic conditions. For example, a ground antenna receiving a transmission from a spacecraft at LEO has a higher slew rate than antennas tracking deep space missions. In addition, Doppler and RF interference is higher and more dynamic for these missions.