Frequency Reuse Reduction for IS-136 Using a Four Element Adaptive Array
Jiann-An Tsai, Richard Michael Buehrer · Kluwer Academic Publishers eBooks · 2006
In this paper we present uplink simulation results for two and four element adaptive arrays assuming a TDMA system with an IS-136 slot structure. The results consist of the simulated bit error-rate (BER) performance assuming the use of two and four element adaptive arrays with three different frequency reuse patterns. Simulations are also run for a baseline two branch diversity system using standard combining. The results show that by using a four element array in each of three sectors, a frequency reuse of four can be supported on the uplink with up to an additional 2dB gain with respect to the baseline system using a reuse of seven. The four element array is also shown to support a reuse of three albeit with less reliability. This paper addresses the uplink only, similar downlink gains must be achieved in order to obtain these capacity improvements. Element correlation is addressed through the use of a multi-element channel model. The majority of the results assume 10 wavelength inter-element spacing which results in low correlation between elements. Relaxing this condition showed severe degradation in array performance. Environments with low angular spread will require either large array apertures ( 30 wavelengths total spacing for four elements) or the use of dual polarization antennas. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.