Improving Bandwidth Utilization in a 1 Tbps Airborne MIMO Communications Downlink.

摘要

FEC techniques are compared for di erent MIMO con gurations of a high altitude, extremely wide bandwidth radio frequency downlink. Monte Carlo simulations are completed in MATLAB(trade name) with the aim of isolating the impacts of turbo codes and LDPC codes on system throughput and error performance. The system is modeled as a transmit-only static array at an altitude of 60,000 feet, with no interferers in the channel. Transmissions are received by a static receiver array. Simulations attempt to determine what modulation types should be considered for practical implementation, and what FEC codes enable these modulation schemes. The antenna con gurations used in this study are 44:352, 62:248, and 80:160 transmitters to receivers. E ects from waveform generation, mixing, down-conversion, and ampli cation are not considered. Criteria of interest were BER and throughput, with the maximum allowable value of the former set at 1 x 10(-5), and the latter set at a 1 terabits per second (Tbps) transfer rate for a successful con guration. Results show that the best performing system con guration was unable to meet both criteria, but was capable of improving over Brueggen's 2012 research, which used Reed-Solomon codes and a MIMO con guration of 80:160, by 18.6%. The best- case configuration produced a throughput rate of 0.83 Tbps at a BER of less than 1 x 10 to the minus 8th power, by implementing a rate 2/3 LDPC code with QAM constellation of 16 symbols.