Study of spread spectrum multiple access systems for satellite communications with overlay on current services

The feasibility of using spread spectrum techniques to provide a low-cost multiple access system for a very large number of low data terminals was investigated. Two applications of spread spectrum technology to very small aperture terminal (VSAT) satellite communication networks are presented. Two spread spectrum multiple access systems which use a form of noncoherent M-ary FSK (MFSK) as the primary modulation are described and the throughput analyzed. The analysis considers such factors as satellite power constraints and adjacent satellite interference. Also considered is the effect of on-board processing on the multiple access efficiency and the feasibility of overlaying low data rate spread spectrum signals on existing satellite traffic as a form of frequency reuse is investigated. The use of chirp is examined for spread spectrum communications. In a chirp communication system, each data bit is converted into one or more up or down sweeps of frequency, which spread the RF energy across a broad range of frequencies. Several different forms of chirp communication systems are considered, and a multiple-chirp coded system is proposed for overlay service. The mutual interference problem is examined in detail and a performance analysis undertaken for the case of a chirp data channel overlaid on a video channel

A new frequency distribution architecture for wavelength division systems

Includes bibliographical references (p. 10-16)."Presented at Octima '91, Rome, Italy, January 1991."--Cover. Cover title.Research supported by DARPA. F19628-90-C-0002 Research supported by Bellcore, Nynex and NEC.Pierre A. Humblet, Peter C. Li

Satellite fixed communications service: A forecast of potential domestic demand through the year 2000. Volume 3: Appendices

Voice applications, data applications, video applications, impacted baseline forecasts, market distribution model, net long haul forecasts, trunking earth station definition and costs, trunking space segment cost, trunking entrance/exit links, trunking network costs and crossover distances with terrestrial tariffs, net addressable forecasts, capacity requirements, improving spectrum utilization, satellite system market development, and the 30/20 net accessible market are considered

Application of advanced on-board processing concepts to future satellite communications systems

An initial definition of on-board processing requirements for an advanced satellite communications system to service domestic markets in the 1990's is presented. An exemplar system architecture with both RF on-board switching and demodulation/remodulation baseband processing was used to identify important issues related to system implementation, cost, and technology development

Coherent multicarrier lightwave technology for flexible capacity networks (invited)

Highly flexible and survivable networks can be built by allocating optical carriers of heterodyne systems. The basic features of heterodyne systems are reviewed, especially the use of multicarriers, tunability, and selectivity. Then specific application areas that may benefit from flexible multicarrier allocation schemes are discussed. Examples are taken from the RACE Phase II project R2065, coherent optical systems implemented for business traffic routing and access (COBRA). Next, trends and progress in heterodyne systems in general and related key components are summarized, and then examples of ongoing field trials in Europe are discussed. Finally, the coherent multicarrier technology are compared briefly with direct detection multiwavelength technolog