Assessment of cochannel interference in fixed wireless cellular systems

Abstract

In wireless cellular systems cochannel interference is the limiting factor in determining the capacity. Fixed wireless systems such as MMDS and LMDS are no exception to this rule. In this paper, we analyzed the signal-tointerference ratio in a highly-overlapped cellular architecture. Through macro diversity, such a cellular architecture can provide significant diversiq gains but it is vulnerable to excess cochannel interference. Analyzing the cochannel interference at the worst case point in the center of a cell shows that polarization interleaving can increase signal-to-interference ratio by several decibels.

Millimeter-Wave Base Station Diversity for 5G Coordinated Multipoint (CoMP) Applications

“…Cell-site diversity was studied as a method to mitigate the effects of rain and vegetation attenuation in [8], [9]. In early LMDS studies, polarization interleaving between neighboring BSs was shown to increase signal-to-interference ratio (SIR) by several dB, although, depolarization from foliage and rain resulted in limited improvement or even degradation due to co-channel interference [10]. LMDS simulations in [11] revealed that using highly directional antennas at the BS and mobile could dramatically improve system performance by reducing co-channel interference, and system outage by an order of magnitude [11].…”

“…We now further decompose (10) to show the received signal, y k,i ∈ C 1×1 of the i-th stream for the k-th user:…”

Assessment of co-channel interference in fixed wireless cellular system operating at Ka band

“…However, according experimental measurements, results show that the depolarisation by trees is an order of magnitude larger than the corresponding values for rain depolarisation [2,4]. Therefore, only the depolarisation of vegetation is considered.…”

“…Applying dual polarization and combining the interleaved channel assignment scheme, the intra-cell polarization interleaved cellular are proposed by S. Farahvash and M. Kavehrad [2] to reduce co channel interference as shown in Fig. 1.…”

“…Therefore, multiple LMDS hubs are arranged in a cellular fashion to cover the wide service area and reuse the frequency spectrum. It is well known that co-channel interference is a limiting factor for cellular communication system and intelligent cellular design is expected to improve system performance [2,3]. To reduce co-charmel interference in this fixed broadband wireless cellular network, each cell is divided into multiple sectors and each of them served by a sector antenna collocated with the hub.…”