Quality of Service of Broadband Fixed Wireless Access QPSK Channels Interfered by Adjacent Terrestrial Links

A physical model is presented concerning the quality of service (QoS) statistics of broadband fixed wireless access (BFWA) QPSK channels interfered by adjacent terrestrial links operating at the same frequency. The QoS is quantified in terms of the bit-error probability (BEP) of the link. BFWA networks of current interest are mainly operated above 10 GHz assuming line-of-sight (LoS) connection between the base station and the subscriber terminal. In these network configurations, rain attenuation is the dominant fading mechanism and its statistical behavior severely aggravates the nominal interference environment due to the spatial inhomogeneity of rain. The BEP of a coherent QPSK demodulator in the presence of Gaussian noise, cochannel interference and rain attenuation is determined and is related to the relevant performance masks recommended by ITU-R. Numerical results of the proposed model examine how the frequency of operation, the clear-sky interference levels, the length of the interfering path and the climatic conditions affect the QoS of BFWA channels. The spectral and spatial coexistence of BFWA networks and point-to-point links is investigated