Temporal variation characterization for LMCS channel and system design implications

by Naz, Nausheen

Local MuItipoint Communications Services (LMCS) is a broadband wireless access technol- ogy for the provision of multi-media communication services to subsmibers at fixed locations. Due to the unavailability of large bandwidth at lower fiequency band, these systems will oper- ate in the frequency range of 23 to 40Gbz (in North America). The successfiil operation of point to multipoint system (LMCSKMDS) at these frequencies necessitates the exact channel characterization. LMCS systems designed with actual chamel characteristics will provide hi& spectral efficiency dong with quality of service QoS guarantees comparable to other competitive access technologies (for example, Hybrid Fiber Coaxiai, Digital Subscriber Line, Passive Optical Networks). In this work, we studied the temporal fading characterization at 29.5GHz using narrowband (CW) rneasurements at 29.5GHz. Frorn the measurements we obtained envelope distributions. statistics of fade rate and fade duration for several radio link environment, including those affected by wind-blown foliage and others affected by moving vehicles acting as scatters and reflectoa. Based on these measurement results we studied the performance of adaptive modulation schemes, popular channel coding schemes, requîrements for interleavers with and without ARQ (automatic repeat request). several power control algorithms are dso suggested. Furthemore, we studied the performance of DAW 1.2 physical layer recommendations for G.8 26 defined parameters. Temporal Variahns Chmcî- d mCnnirdnd S* Pagt fi