Performance prediction of WLAN speech and image transmission

The effects of multipath, noise, and cochannel interference on performance are shown for two wireless local area networks (WLAN). Measured impulse responses from an office environment provided the multipath distortion. The first WLAN system uses frequency hopped (FH) Gaussian frequency shift keying (GFSK) and the second uses direct sequence (DS) differential binary phase shift keying (DBPSK). Both modulations are part of the proposed WLAN IEEE 802.11 standard. Vocoded speech and image quality were predicted for wireless systems through software simulation by relating quality classes to the following system and channel operational parameters: bit error rate (BER), signal-to-noise ratio (SNR), and carrier-to-interference ratio (CIR). Experimental results are summarized by overlaying image and vocoded speech quality classes on a BER, SNR, and CIR graph