Yiyang Ni

Outage probability of device-to-device communication assisted by one-way amplify-and-forward relaying

This study investigates the outage probability of device-to-device communication assisted by a relay node utilising a one-way amplify-and-forward relaying strategy. The authors assume that all the terminals are equipped with a single antenna and all the users know perfect channel state information. They first derive the exact closed-form expression for characterising the outage probability performance of the system. They subsequently discuss several special scenarios and obtain the asymptotic results for each of the considered scenarios. The results can be easily computed with only the channel statistics. Based on the analysis in the high signal-to-noise ratio regime, closed-form power allocation policies are developed to improve the outage probability performance. The authors analytical results are validated via Monte Carlo computer simulations.

Beamforming and Interference Cancellation for D2D Communication Underlaying Cellular Networks

This paper presents an analytical performance investigation of both beamforming (BF) and interference cancellation (IC) strategies for a device-to-device (D2D) communication system underlaying a cellular network with an M-antenna base station (BS). We first derive new closed-form expressions for the ergodic achievable rate for BF and IC precoding strategies with quantized channel state information (CSI), as well as, perfect CSI. Then, novel lower and upper bounds are derived which apply for an arbitrary number of antennas and are shown to be sufficiently tight to the Monte-Carlo results. Based on these results, we examine in detail three important special cases including: high signal-to-noise ratio (SNR), weak interference between cellular link and D2D link, and BS equipped with a large number of antennas. We also derive asymptotic expressions for the ergodic achievable rate for these scenarios. Based on these results, we obtain valuable insights into the impact of the system parameters, such as the number of antennas, SNR and the interference for each link. In particular, we show that an irreducible saturation point exists in the high SNR regime, while the ergodic rate under IC strategy is verified to be always better than that under BF strategy. We also reveal that the ergodic achievable rate under perfect CSI scales as log2M, whilst it reaches a ceiling with quantized CSI.

Outage analysis for device-to-device communication assisted by two-way decode-and-forward relaying

In this paper, we investigate the outage probability of device-to-device (D2D) communication assisted by decode-and-forward (DF) relay node and that using traditional strategy. We assume all terminals are equipped with single-antenna. We first derive closed-form expressions for the outage probability of the D2D link under asymmetrical and symmetrical cases respectively. Then we derive tight approximations of the outage behavior in the high signal-to-noise (SNR) regime under the two cases. Based on these results, we then show that the D2D communication aided by DF relay node gains advantages over that of the traditional strategy without extra power. Numerical results demonstrate that the analytical results are accurate on various conditions.

Outage performances for device-to-device communication assisted by two-way amplify-and-forward relay protocol

This paper studies the outage probability of device-to-device (D2D) communication aided by another D2D user using the two-way amplify-and-forward (AF) relaying protocol. We first discuss the outage behavior under strong and weak interference from the cellular network. Then the exact expressions for the outage probability under the two cases are derived. Based on these results, we give tight approximations in the high signal-to-noise (SNR) regime under the two cases. Numerical results show that the outage behavior for the relay aided D2D link can be greatly enhanced without extra power. Analytical results are validated via comparisons with the Monte-Carlo simulations.

Beamforming and interference cancellation schemes for D2D communications

We investigate device-to-device (D2D) communication underlaying cellular networks with M-antenna base stations. We consider both beamforming (BF) and interference cancellation (IC) strategies under quantized channel state information (CSI), as well as, perfect CSI. We derive tight closed-form approximations of the ergodic achievable rate which hold for arbitrary transmit power, location of users and number of antennas. Based on these approximations, we derive insightful asymptotic expressions for three special cases namely high signal-to-noise (SNR), weak interference, and large M. In particular, we show that in the high SNR regime a ceiling effect exists which depends on the received signal-to-interference ratio and the number of antennas. Moreover, the achievable rate scales logarithmically with M. The ergodic achievable rate is shown to scale logarithmically with SNR and the antenna number in the weak interference case. When the BS is equipped with large number of antennas, we find that the ergodic achievable rate under quantized CSI reaches a saturated value, whilst it scales as log2M under perfect CSI.

Transmission mode switching for device-to-device communication aided by relay node

In this paper, we investigate the strategy of transmission mode switching for device-to-device (D2D) communication in both single-cell scenario and multi-cell scenarios, which selects the transmission mode to guarantee the maximum ergodic achievable sum-rate among three transmission modes. We first introduce the basic operation principles of three communication transmission modes which are named as traditional cellular communication mode, direct D2D communication mode and two-way decode-and-forward (DF)-relayed D2D communication mode. Then we derive the corresponding expressions for the ergodic achievable sum-rates of each transmission mode, and get the crossing points of different transmission modes to attain maximum ergodic achievable sum-rate of the system. From the analytical results, we can see that the proper operating region of each transmission mode is related to different interference level and distance of the D2D users. Based on the analytical results, we obtain a reliable communication transmission mode switching strategy which guarantees the system to choose the mode with the maximum ergodic achievable sum-rate so as to improve the performance of D2D communication. Numerical results demonstrate that by applying mode switching, the ergodic achievable sum-rate of the system achieves a remarkable enhancement.

Pareto-optimal power allocation of device-to-device communication with two-way decode-and-forward helping relay

This paper considers a new strategy utilizing two-way decode-and-forward (DF) relaying for device-to-device (D2D) communications underlaying cellular networks. Assuming that all the terminals have single antenna, we first derive the sum-rate expressions for both the D2D and cellular links and then propose a Pareto-optimal method to maximize the achievable sum-rate of both D2D and cellular links. Simulation results demonstrate that the sum-rate for the D2D link can be greatly enhanced without compromising the performance of the cellular link.

Correction to: Two-way DF relaying assisted D2D communication: ergodic rate and power allocation

CorrectionUnfortunately, the original version of this article [1] contained an error. The affiliation of Yiyang Ni and Yuxi Wang was incorrect. The correct affiliation is Jiangsu Second Normal University and is presented in this correction.

Interference mitigation scheme by antenna selection in device-to-device communication underlaying cellular networks

In this paper, we investigate an interference mitigation scheme by antenna selection in device-to-device (D2D) communication underlaying downlink cellular networks. We first present the closed-form expression of the system achievable rate and its asymptotic behaviors at high signal-to-noise ratio (SNR) and the large antenna number scenarios. It is shown that the high SNR approximation increases with more antennas and higher ratio between the transmit SNR at the base station (BS) and the D2D transmitter. In addition, a tight approximation is derived for the rate and we reveal two thresholds for both the distance of the D2D link and the transmit SNR at the BS above which the underlaid D2D communication will degrade the system rate. We then particularize on the small cell setting where all users are closely located. In the small cell scenario, we show that the relationship between the distance of the D2D transmitting link and that of the D2D interfering link to the cellular user determines whether the D2D communication can enhance the systemachievable rate. Numerical results are provided to verify these results.

Interference-Mitigation Based Antenna Selection Scheme in Device-to-Device Communication Underlaying Cellular Networks

This paper investigates an antenna selection scheme performing interference mitigation in device-to-device (D2D) communication underlaying cellular networks. Exact closed-form expression of the ergodic achievable rate is derived. Based on this result, the analysis in the high SNR regime at the base station (BS) and the scenario with very large antenna number are investigated, which indicate the saturation of the ergodic achievable rate when these parameters grow very large. Next, two approximations are then shown to be fairly tight, thus yielding much simpler expression of the ergodic achievable rate. Furthermore, we provide the performance analyses in the small cell and macro cell respectively and show that in the small cell, the high SNR approximation of the ergodic achievable rate varies proportionally with the transmit power ratio between the BS and the D2D transmitter. In the macro cell setting where the pathloss factor between the D2D terminals becomes much larger, we show that the ergodic achievable rates improvement potentials by increasing the antenna number can be elevated with higher transmit power at the BS. Numerical results are then provided to verify the correctness of the expressions derived above. Some observations are made accordingly.