A TDMA system design for Space Station Freedom UHF communications

An ultrahigh frequency, time-division multiple-access (TDMA) communication system for voice and data communications between the US Space Station Freedom, its inter-operating elements, and a space shuttle is currently under study. The proposed design will use a fixed-assignment 24 ms frame with 12 slots for voice, data, command, and telemetry and will operate at a burst data rate of 500 kb/s using DPSK modulation. The requirements and design issues associated with the proposed TDMA approach are discussed. Several factors of the frame design are examined and analyzed, including frame and data burst structure, frame acquisition and tracking performance, selection of unique world lengths, bit synchronization preamble length, and guard band sizing.<
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