Performance analysis of LMS adaptive filtering for PMP radio system applications

Point to multipoint (PMP) radio systems normally operate in propagation environments where significant delay spreads may be encountered due to the fact that, in base stations, sectorial or even omnidirectional aerials are employed. In most of the cases there is a line of sight link but, because of lateral/ground reflections and because most of the times neither antenna can be mounted clear of local clutter, sometimes there is a high possibility of multipath dispersion. In point to point systems the solutions to avoid the multipath phenomena are well known: space, frequency or even angle diversity and adaptative equalizers. The present paper considers time domain adaptative equalizers (ATDE) in a PMP TDMA environment. A comparison between different equalization methods is made, always in a TDMA environment. Some considerations over the fixed point realization of the schemes are presented; and its physical implementation is contemplated