Experiments on postdetection diversity for narrowband digital FM mobile radio

Postdetection diversity, in which the demodulator outputs are weighted in proportion to the vth power of each demodulator input signal envelope when they are added, is described for GMSK signal reception using a frequency demodulator and a one-bit decision feedback equaliser. Experiments on a 16 kbit/s GMSK with a premodulation filter bandwidth-bit duration product of B_bT=0.25, show that using v=2 provides a diversity gain about 1-1.5 dB larger than selection combining, at an average bit error rate of 10^-2 in a Rayleigh fading environment