A fiber infrastructure for microcellular personal communication systems: Infrastructure design and optical dynamic range requirements.

摘要

The main goals of personal communications systems (PCS) are service availability over an extremely high percentage of user environments, and provision of enhanced services. Infrastructures for PCS must minimize remote antenna size and cost, reduce system hardware requirements, and facilitate system maintenance and upgradeability. These goals can be met by a centralized PCS infrastructure using analog fiber-optic links.; Noise and nonlinearities generated by optical components within PCS or cellular infrastructures can degrade overall PCS or cellular system performance, and thus performance requirements in terms of spurious-free dynamic range (SFDR) for optical links within these infrastructures must be found. To determine these requirements, the relationship between optical link SFDR and wireless system performance must be accurately quantified. Though there have been previous efforts to approximate SFDR requirements for centralized processing infrastructures in conventional cellular systems, no comprehensive wireless/optical model for the accurate determination of these requirements has been developed for either conventional cellular systems or microcellular PCS.; A novel, comprehensive wireless/optical model of a centralized PCS fiber infrastructure is presented in this thesis. Results of the simulation indicate: (i) SFDR is an accurate measure of fiber link impact on PCS system availability; (ii) SFDR requirements for PCS are in the 72 to 83 {dollar}rm dBcdot Hzsp{lcub}2/3{rcub}{dollar} range; and (iii) larger power control range, selection diversity, larger distance loss, and lower shadowing variance result in lower SFDR requirements. SFDR requirements for cellular systems are more stringent, and are found to range from 93 to 105 {dollar}rm dBcdot Hzsp{lcub}2/3{rcub}{dollar}.; Results for infrastructure design are: (i) required automatic gain control (AGC) accuracy is about 8 dB for PCS and cellular systems, and decreases with increasing optical link SFDR. (ii) Distributed feedback (DFB) and Fabry-Perot semiconductor laser diodes can be used in PCS infrastructures. DFB lasers are required in cellular infrastructures. (iii) A base station star topology has a potential coverage area larger than that for either concentrator or bus topologies in both PCS and cellular infrastructures. For a 10 dB optical power budget, base station coverage areas of 5000, 2500, and 800 square kilometers are attainable using the star, concentrator, and bus topologies, respectively.