A bound on frequency hopped GSM performance in co-channel interference

The GSM and DCS-1900 mobile telephone systems have a large number of signal processing and configuration parameters that must be set by the base station (BS) designer or system operator. A computationally efficient method of determining the system performance is needed in order to conduct parameter tradeoffs, and select the best system configuration. In addition to fading and shadowing loss experienced by the signal, the required method must reflect large variations of interference power that occur within a speech frame, due to frequency hopping and discontinuous transmission. Such a method is described. An upper bound on the frame erasure rate is developed using a simplified channel model. The bound provides a simple test for whether or not a link can be closed. Cell coverage calculations based on this test are demonstrated for a single source in Rayleigh fading, and for a co-channel interference limited environment. The fading results are within 0.4 dB of simulation results for a similar system.