Sensitivity and range in WLAN receivers

The WLAN receiver is expected to operate in a non benign RF environment. In the 2.4 GHz band, sharing with the ISM (industrial, scientific, medical) service leads to this conclusion, while in any band, the expected commercial success suggests that the number of users will result in an interference limited environment. Under these circumstances, the performance of receivers is limited by parameters other than sensitivity, and this paper examines those parameters and attempts to set bounds upon their requirements. Although it would appear at a first examination that the range of a WLAN receiver is directly proportional to the receiver sensitivity, it is shown that the effects of phase noise in particular, followed in order of importance by gain compression and intermodulation can cause a significant diminution in the effective receiver sensitivity, and thus the achievable range. Additionally, phase noise contributions limit the selectivity that can be achieved, and can effectively negate the contributions of IF filters, while in system considerations, the phase noise of adjacent transmitters cannot always be neglected.