Least squares based post-integration filtering for robust digital LDI receivers

Short range radio systems such as Bluetooth and DECT (digital enhanced cordless telecommunications) use GFSK (Gaussian frequency shift keying), a continuous phase modulation scheme derived from MSK (minimum shift keying). In this communication, the authors discuss the design of a generalized least squares (GLS) based post-integration filter, which increases the robustness of digital limiter-discriminator-integrator (LDI) receivers. As an example, MSK is used to illustrate the receiver performance.