Time Dispersion Parameters Of Outdoor Cross-Polar Self-Interference Radio Channels In Sub-8-Ghz Bands

Indeed, self-interference cancellation has been proven to be the key-enabling technique for realizing a full-duplex duplexing scheme. However, a self-interference canceller must possess an up-to-date knowledge about its sensed self-interference wireless channel. In wireless communication systems, these channels usually possess multi-path and time-invariant properties. Moreover, they are very environment dependant. Therefore, in this paper we chose to investigate outdoors experienced channels, more specifically, ones are encountered in a street-level deployment scenario. Furthermore, we narrowed down the focus to concentrate on cross-polar self-interference channels. These channels are observed in dually polarized antenna's configurations among transmitter and receiver ones.In nutshell, we have dedicated this paper to study the multipath propagation characteristics of outdoor cross-polar self-interference radio channels. By means of an empirical method, time dispersion behavior of our measured self-interference channel was analzyed. To measure a cross-polar self-interference channel, a channel sounding experiment equipped with a dually-polarized ridged horn antenna was performed. For that purpose, we assembled a channel sounding setup, which is composed of a vector network analyzer connected to the dually polarized antenna. The measurement antenna was placed at 3.5m height, where measurement data were captured at 26 different locations -on a route parallel to the street. Additionally, for the sake of investigating the frequency dependancy on a cross-polar self-interference channel, two broad frequency bands were measured: A band between 2.9GHz and 4.1 GHz, and a band between 5.9GHz and 7.1 GHz. Finally, we derive-from measurement data-empirical probability distributions of channels' time dispersion parameters, such as the maximum peak of the self-interference backscatter (SIBS) channel gain, channel delay spread, and maximum excess delay. These statistical analysis results are presented for both measured frequency bands.