SDR Based Implementation of MSK and GMSK Receiver in Rich Multipath Environment

This paper presents software defined radio based implementation of Minimum Shift Keying (MSK) and Gaussian Minimum Shift Keying (GMSK) digital receiver. The performance of MSK receiver and GMSK receiver is assessed under practical multipath fading scenario in mode-stirred metal enclosure. Metal enclosure when stirred with pedal creates rich isotropic multipath fading environment. The isotropic field and the severity of fading can be reduced by placing radiation-absorbent material (RAM) in the metal enclosure. The effect of addition of number of absorbers is to reduce the number of scattered waves hence reduce isotropic field distribution in the enclosure. This effect has direct implication of increased Rician K-factor. The performance of MSK and GMSK receiver is analyzed when the metal enclosure was loaded with few pieces of RAM.