Outage probability for a frequency-selective fading digital portable radio channel with selection diversity using coding

The outage probability for a time division multiple access (TDMA) portable radio channel with diversity selection based on coding is obtained by using computer simulation. Coherent detection of a quaternary phase shift keying (QPSK) signal with spectrally raised-cosine Nyquist pulse with 0.5 roll-off factor is used as an example. Different performance criteria are used to define outage. The outage probability as a function of the normalized RMS time delay spread is then used to determine the maximum transmission rate than can be supported by a portable radio channel. It is found that for a performance objective of 1% or less outage, a transmission rate of several hundred kb/s is possible. The use of two-branch selection diversity can increase the channel capacity by about a factor of 3 or more