Interference Management in Underlay Spectrum Sharing Using Indirect Power Control Signalling

Abstract

Abstract-In this paper, we propose an interference management method for underlay spectrum sharing and evaluate its performance. In this method the secondary service has been facilitated by granting passive access to the power control signalling transmitted by the primary network base station. To exploit both slow shadowing and fast fading, the proposed method performs secondary service power management in two phases, each in different time-scales: rate optimal power allocation phase and interference reduction power adjustment phase. In the longer time-scale, rate optimal power allocation phase adaptively allocates the secondary transmit power exploiting the medium-scale channel variations (shadowing effect) of the secondary channel to maximize its capacity. In the shorter timescale, interference reduction power adjustment phase exploits the power control commands transmitted in the primary network to adaptively adjust secondary service transmission power for reducing the effects of the secondary service transmission on the Quality-of-Service (QoS) of the primary service network. The main advantage of this method which is referred to as Adaptive Multiple Time-Scale Power Allocation (AMTPA) is that it does not require direct signaling between the two systems. We further present AMTPA analytical performance evaluation results. Practical considerations are also presented regarding the primary network requirements and its power control feasibility after adopting AMTPA in the secondary network. Extensive simulation results indicate significant improvement in the system performance by using AMTPA. Using simulations we also show how one can set AMTPA parameters so that a certain level of QoS in the primary network is satisfied.Index Terms-Collision probability, DS-CDMA, interference management, underlay spectrum access, spectrum sharing.

Cognitive decode-and-forward relaying with successive interference cancelation

“…The distance between SR and SD is d rd = (1 − β) 2 d 2 sd + (θd int ) 2 . Similar to the simulation setup of [3,10,19], unless specified otherwise, we set the system parameters as α = 3, = 0.2, ρ = β = 0.5, θ = 0.25, N 0 = − 80 dBm, p p = p s = p r = 0 dBm, p m = 20 dBm, R p = 1 bits/s/Hz, R s = 0.5 bits/s/Hz, d pa = d int = 200 m, and d sd = 100 m.…”

“…Either the interference-alignment or the beamforming technique can be adopted by PUs and SUs to mitigate the mutual interference [17,18]. An adaptive power allocation scheme was proposed in [19], where SUs can access the power control signaling of PUs and control their powers in both the long-time and short-time scales to improve the capacity of secondary system while guaranteeing the QoS of PUs [19]. Since the underlay mode will result in low transmission efficiency due to restricted power, to maximize the throughput of secondary system, researchers have proposed dynamic overlay-underlay and interweaveunderlay spectrum sharing schemes based on the statuses of PUs [20][21][22][23].…”

“…Substituting (45), (48), and (48) into (49), and after some simplifications, we can derive the result of (19).…”

Cooperative Overlay Spectrum Access in Cognitive Radio Networks

“…Kehao Wang et al [79] An underlay CR communication system in which a CU can access multiple primary spectrum channels only when its interference to the PU is limited. Khoshkholgh et al [80] An interference management method for underlay spectrum sharing are proposed, which the secondary service has been facilitated by granting passive access to the power control signalling transmitted by the primary network base station. GaoJie et al [81] A decode-and-forward buffer-aided relay selection has been proposed for underlay cognitive relay networks in the presence of both primary transmitter and receiver.…”

Spectrum sharing in wireless cellular networks

“…In terms of interference margin, [77] gave the interference margin as a predefined value without justification, and [81] evaluated it based on the outage of CDMA SINR by approximating the CDMA inter-user interference as additive white Gaussian noise (AWGN).…”