Investigation of methods to improve interference immunity in detection and direction-finding of IEEE 802.11bf signals

The development of joint identification and direction-finding methods enables the separation of bearings from a large number of wireless communication signal sources operating in the same frequency band with time-division access [21–26]. This work focuses on the detection of target signals and the extraction of source identification features, as the effectiveness of these operations significantly affects the overall quality of direction-finding. This paper investigates the potential for improving the interference immunity of detection, identification, and direction-finding processes for IEEE 802.11bf signals through the use of a two-channel correlation-interferometric receiver. A structural principle of the proposed innovative solution is presented, based on spatio-temporal signal processing that accounts for channel correlation, frequency offset, and Rayleigh fading conditions. A research methodology for the two-channel receiver is developed, including modeling of reception processes, correlation-based detection, signal parameter estimation, and angle-of-arrival determination. Formalized mathematical models are formulated to describe the bit error probability, detection probability, false alarm rate, and direction-finding accuracy as functions of the signal-to-noise ratio, channel correlation coefficient, and frequency offset. MATLAB simulation results demonstrate that two-channel reception significantly reduces the bit error probability compared to the single-channel case, while increasing the probability of correct signal detection at a fixed false alarm rate. It is shown that the accuracy of angle-of-arrival estimation strongly depends on channel correlation and frequency offset: increasing correlation degrades interferometric properties, whereas frequency offset introduces phase errors and increases the root-mean-square estimation error. The results confirm the effectiveness of the proposed approach for enhancing the interference immunity of radio monitoring and cognitive radio systems based on IEEE 802.11bf.