Zhonghua Yu
Chongqing University of Posts and Telecommunications

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Journal : TELKOMNIKA (Telecommunication Computing Electronics and Control)

Adaptive Resource Allocation Algorithm in Wireless Access Network Zhanjun Liu; Yue Shen; Zhonghua Yu; Fengxie Qin; Qianbin Chen
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 14, No 3: September 2016
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v14i3.3615

Abstract

Wireless network state varies with the surrounding environment, however, the existing resource allocation algorithm cannot adapt to the varying network state, which results to the underutilization of frequency and power resource. Therefore, in this paper, we propose an adaptive resource allocation algorithm which can efficiently adapt to the varying network state by building an optimal mathematical model and then changing the weighted value of the objective function. Furthermore, the optimal allocation of subcarrier and power is derived by using the Lagrange dual decomposition and the subgradient method. Simulation results show that the proposed algorithm can adaptively allocate the resource to the users according to the varying user density which represents the network state.
Efficient D2D Discovery Scheme for Channel Measurement of Interference Alignment Zhanjun Liu; Yunpeng Li; Zhonghua Yu; Yue Shen
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 14, No 2: June 2016
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v14i2.3148

Abstract

Device-to-device (D2D) communications have the potential to improve spectrum efficiency and link capacity by allowing nearby devices to communicate directly with each other on the licensed frequency bands. Hence, co-channel interference (CCI) among D2D users are major issues to be solved when they are utilizing the same frequency bands. Consequently, interference alignment (IA) as an effective interference management approach has been implemented to the D2D communications for the frequency sharing. However, the measurement of channel state information (CSI) between transmitter and receiver of a D2D pair and cross-channel state information (C-CSI) among D2D pairs are the major issues that need to be resolved for the implementation of IA from theory to practical. Therefore, in this paper, we propose an effective D2D discovery scheme to overcome this problem, which can measure the CSI and C-CSI based on the transmission of discovery messages. Simulation results show that, under perfect conditions, even though the proposed D2D discovery scheme increases the needed time slots to establish D2D communications compared with the conventional D2D discovery without considering IA by 6.2%, it increases the throughput up to 50% than the conventional D2D communications without considering IA, i.e., it improves the spectrum efficiency.