Joint Power and Channel Allocation for Underlay D2D Communications with Proportional Fairness

Abstract

Since D2D (Device-to-Device) communication was proposed in cellular network as a new paradigm for enhancing network performance, many works have been done on resource allocation to improve system throughput and energy efficiency (EE) for underlay D2D communications. However, the system long-term average fairness as one of the system main performance metrics was rarely considered especially when users are moving. In this paper, we formulate the joint power and channel allocation problem aiming at maximizing the system fairness subject to the minimum required SINRs (Signal to Interference and Noise Ratios) and power consumption limits of cellular and active D2D links. To solve the above problem practically, we first decompose our original problem into two sub-problems (power and channel allocation), then solve them sequentially. Simulation results show that our proposed algorithm can dramatically enhance the system fairness and slightly improve the system throughput comparing with existing method.

Resource Allocation for D2D Underlay Communications With Proportional Fairness Using Iterative-Based Approach

“…Improved-scheme: In [21], we assume that the RBs of cellular links are pre-allocated as did in [20]. The fairness is taken into account for both power and channel allocation in all scheduling periods.…”

“…where P t and χ t are the K × L × N power and channel allocation matrices at time t. Φ t is the K × N channel allocation matrix. The channel allocation index Φ t i,n = 1, if cellular link i occupies RB n exclusively, otherwise, Φ t i,n = 0 in scheduling period t. χ t i,j,n = 1, if cellular link i and D2D link j reuse the same RB n, otherwise, χ t i,j,n = 0 in scheduling period t. In (21), the first term is the sum of the ratios for cellular links without reusing; the second term is the sum of the ratios for cellular links with channel reusing, and the last term is the sum of the ratios for all D2D links. Constraints (21a)-(21h) in scheduling period t are equivalent to (11a)-(11f ).…”

“…To simply the system model, work in [20] assumes that the system is completely fair when allocating the transmission power for both cellular and D2D links, which is unrealistic and will lead to an unfair system. Our work in [21] enhances the system fairness by taking into account the previous average data rates into power allocation.…”