DFE equalizers for GMSK with limiter-discriminator detection in frequency selective fading environment

The conventional decision feedback equalizer (DFE) is a common solution to the frequency selective multipath propagation problem that appears in high data rate radio communications because of its simplicity and good performance. However, when limiter-discriminator (LD) is used for detection of GMSK signals, the global system has a nonlinear characteristic and the conventional DFE yield poor performance even for moderate delay-spread (DS) channels. An envelope-aided DFE is proposed that extends the use of GMSK with LD to high DS channels at a minimum increase in complexity and cost. The performance has been evaluated for both fractionally-spaced (FS) and T-spaced (TS) DFEs, using the exponential power-delay profile channel model.