TABLE OF CONTENTS Various receiver performance and functional tests are also performed during general design and development as well as for design verification. Some of the more Significant tests are described in this section.
Sensitivity and dynamic range (blocking dynamic range, third-order intermodulation (IMD) dynamic range, etc.) are key parameters for any type of receiver. Adjacent channel rejection (ACR) is an important performance parameter for a channelized digital radio, which is what a WLAN receiver fundamentally is. For WLANs, these metrics are generally measured in terms of signal levels required to produce a BER less than or equal to some specified threshold, with a test setup as shown below:
The measurement of sensitivity is straightforward. Only one of the VSGs in the above setup is used; the other is deactivated or removed (and a terminator applied in its place). The active VSG is set to a fixed output power and configured to generate a stream of WLAN frames of a fixed frame size, with a fixed PHY bit rate, and at a fixed frame rate; the output power from the VSG is set to a convenient but known value. The attenuation is progressively increased until the received BER rises above a given threshold, depending on the 802.11 PHY technology used. The sensitivity of the receiver is then merely the VSG output level (in dB) minus the attenuation (also in dB).
As it is...
