Combined effects of RF impairments in the future IEEE 802. 11n WLAN systems

In this paper, the overall performance degradation of an IEEE 802.11n WLAN system due to MIMO RF interference, AM-AM distortion of power amplifier, IQ mismatches, phase noise and their combined effects in transmitter are investigated. To extract more relevant values of RF impairments, we observed constellation diagram and the error vector magnitude (EVM) of the complete RF/modem link as a figure of merit. In addition, we propose the novel and first method for the model of the MIMO RF interference from the neighboring RF chains. We also study the implication of its presence on the performance when coupled with other RF impairments. By analyzing the experimental results, the range of values for MIMO interference, PA backoff, gain/phase error, and phase noise can be determined over which a IEEE 802.11n WLAN transmitter operates while maintaining a tolerable level of performance.