[Paper Review] Device-to-Device Communication Underlaying a Finite Cellular Network Region

Jing Guo, Salman Durrani+2 more|arXiv (Cornell University)|Oct 12, 2015

Advanced MIMO Systems Optimization39 references5 citations

TL;DR

This paper proposes a D2D mode selection scheme in a finite cellular network region to manage intra-cell interference in underlay in-band D2D communication. Using stochastic geometry, it models D2D user locations as a Poisson Point Process and derives the outage probability at the base station and D2D receiver, showing that a slight reduction in cellular path-loss exponent can maintain high spectrum reuse ratio while increasing successful D2D transmissions with higher D2D density.

ABSTRACT

Underlay in-band device-to-device (D2D) communication can improve the spectrum efficiency of cellular networks. However, the coexistence of D2D and cellular users causes inter-cell and intra-cell interference. The former can be effectively managed through inter-cell interference coordination and, therefore, is not considered in this work. Instead, we focus on the intra-cell interference and propose a D2D mode selection scheme to manage it inside a finite cellular network region. The potential D2D users are controlled by the base station (BS) to operate in D2D mode based on the average interference generated to the BS. Using stochastic geometry, we study the outage probability experienced at the BS and a D2D receiver, and spectrum reuse ratio, which quantifies the average fraction of successfully transmitting D2D users. The analysis shows that the outage probability at the D2D receiver varies for different locations. Additionally, without impairing the performance at the BS, if the path-loss exponent on the cellular link is slightly lower than that on the D2D link, the spectrum reuse ratio can have negligible decrease while the D2D users' average number of successful transmissions increases with increasing D2D node density. This indicates that an increasing level of D2D communication can be beneficial in future networks..

Motivation & Objective

• To address intra-cell interference in underlay in-band D2D communication within a finite cellular network region.
• To model the location-dependent performance of D2D users due to spatial constraints.
• To develop a D2D mode selection scheme based on average interference to the base station.
• To analyze outage probability at the base station and D2D receiver using stochastic geometry.
• To quantify spectrum reuse ratio as a measure of successful D2D transmissions.

Proposed method

• Models the cellular network region as a finite disk and D2D users as a Poisson Point Process (PPP) of potential D2D users (p-DUEs).
• Uses stochastic geometry to derive the outage probability at the base station and a typical D2D receiver, accounting for path-loss and fading.
• Introduces a mode selection criterion where a p-DUE operates in D2D mode only if its interference to the base station is below a threshold ξ.
• Derives the probability of a p-DUE being in D2D mode by analyzing the overlap of two disk regions: one centered at the D2D receiver and another defined by the interference constraint.
• Applies Gamma distribution approximation and binomial expansion to derive a tractable expression for the D2D mode probability under varying path-loss exponents.
• Considers the impact of different path-loss exponents on the cellular and D2D links on the spectrum reuse ratio and outage performance.

Experimental results

Research questions

• RQ1 How does the location of a D2D user within a finite cellular region affect its outage probability and interference to the base station?
• RQ2 What is the optimal D2D mode selection strategy that minimizes interference to the base station while maximizing D2D spectrum reuse?
• RQ3 How does the path-loss exponent on the cellular link compare to that on the D2D link in influencing the spectrum reuse ratio and D2D success rate?
• RQ4 What is the trade-off between maintaining base station performance and increasing the number of successful D2D transmissions in a finite region?
• RQ5 How does the spatial distribution of D2D users affect the overall network performance in terms of outage and spectral efficiency?

Key findings

• The outage probability at the D2D receiver is location-dependent, with higher values observed for users farther from the base station.
• When the path-loss exponent on the cellular link is only slightly lower than that on the D2D link, the spectrum reuse ratio decreases negligibly despite increasing D2D node density.
• An increasing D2D node density leads to a significant increase in the average number of successful D2D transmissions without degrading base station performance.
• The proposed mode selection scheme effectively controls intra-cell interference by restricting D2D transmission based on interference-to-BS threshold.
• The analytical model using stochastic geometry accurately captures the trade-off between D2D gain and cellular link reliability in finite regions.
• The derived expression for D2D mode probability is valid under general path-loss exponents and incorporates both spatial distribution and fading effects.