Communication

Optimal Power Allocation and Capacity of Full-Duplex AF Relaying under Residual Self-Interference
This paper investigates the optimal power allocation scheme and corresponding capacity limit of a full-duplex (FD) dual-hop amplify-and-forward relay system under residual self-interference whose variance is proportional to the λ'th power of the transmitted power (0≤λ≤1). At first, the related optimization problems are shown to be quasiconcave under both per-node a...


Performance Analysis of Primary User RSS/DoA Estimation and Localization in Cognitive Radio Networks Using Sectorized Antennas
In this letter we present analytical performance evaluation of primary user (PU) RSS/DoA estimation and localization through cooperating cognitive radios (CRs). We assume that the CRs are equipped with sectorized antennas, an antenna model we use to describe different types of directional antennas with a low hardware overhead (e.g. only a single RF front-end). We first derive the bias and mean ...
Low-Complexity Decoding for RaptorQ Codes Using a Recursive Matrix Inversion Formula
In this letter, we propose a low-complexity recursive decoding algorithm for rateless RaptorQ codes, the next generation error correction codes adopted by several standards such as DVB-H. Conventionally, the decoding of RaptorQ codes requires inverting a huge receive code generator matrix (RCGM). Instead of such costly matrix inversion, we propose to calculate the inverse of the transmit code g...


A Generalized Water-Filling Algorithm with Linear Complexity and Finite Convergence Time
This letter presents an algorithm with linear complexity and finite convergence time for solving the generalized water-filling (WF) problem. The WF problem is generalized by using a weighted-sum-rate, weighted-sum-power, and peak power constraints. The proposed algorithm solves the optimization problems with concave (power and rate) or quasi-concave (energy-efficiency) objective functions. Addi...
Optimal Long-Term Power Adaption for Cooperative DF Relaying
This paper addresses the problem of relay power adaption in time for half-duplex decode and forward cooperative system with channel side information knowledge at the relay. We derive the optimal power distribution as a solution of a convex optimization problem that maximizes the long-term average end-to-end spectral efficiency while respecting a target long-term average power constraint. We als...


Accurate Delay Analysis in Prioritised Wireless Sensor Networks for Generalized Packet Arrival
This letter presents an accurate delay analysis in prioritised wireless sensor networks (WSN). The analysis is an enhancement of the existing analysis proposed by Choobkar and Dilmaghani, which is only applicable to the case where the lower priority nodes always have packets to send in the empty slots of the higher priority node. The proposed analysis is applicable for any pattern of packet arr...
Optimal Power Allocation for Wireless Sensor Networks with Outage Constraint
This letter considers the power allocation problem for a wireless sensor network, where N distributed sensors transmit delay-limited high rate traffic to a fusion center (FC) via orthogonal channels. The system-level outage event is defined as that the FC can decode none of the messages from the N sensors. We formulate the outage probability minimization problem with a sum power constraint, and...

A Framework for Quality of Service with a Multiple Access Strategy
We study a problem of scheduling real-time traffic with hard delay constraints in an unreliable wireless channel. We consider the uplink channel of an infrastructure network with a base station and a fixed number of wireless users. Packets are generated at a constant rate and they need to be delivered to the base station within a fixed number of slots. In a fading wireless channel, we are inter...
On Coding and Beamforming for Large Antenna Arrays in mm-Wave Systems
Due to the spectrum shortage and demand for much higher data rates, millimeter (mm)-wave communications have received growing attention for cellular communication systems with beamforming that can overcome the severe propagation loss. For a highly correlated channel where the line-of-sight (LoS) exists with strong non-LoS (NLoS) components, which would be a typical case for mm-wave channels, we...

Scheduling in Single-Hop Multiple Access Wireless Networks with Successive Interference Cancellation
We study the optimal scheduling problem for minimizing the length of the schedule required to satisfy the traffic demands of the links in single-hop multiple access wireless networks using Successive Interference Cancellation (SIC). We first formulate the optimal scheduling as a Linear Programming (LP) problem where each variable represents the time allocated to a subset of the links sorted acc...
A Complete Complementary Coded MIMO System and Its Performance in Multipath Channels
In this paper, we propose a new system architecture using complete complementary (CC) codes for a multicarrier MIMO CDMA system to combat multipath fading in wireless channels. Unlike traditional MIMO systems, complementary codes were designed at chip-level to achieve time and frequency-spreading for each antenna. We analyze the system performance in multipath fading channels. A closed form exp...

Diversity-Multiplexing Tradeoff for Opportunistic Access Systems
This letter examines the diversity-multiplexing tradeoff (DMT) for the opportunistic access system (OAS) with a delay-constrained traffic. In particular, the OAS adopts a random access framework: The transmitter first performs channel probing (CP) slot by slot, and in each time slot, it tries to access one of the candidate channels; when the CP is successful, it will decide to transmit or give ...
Co-Channel Interference Mitigation Technique for Non-Coherent OOK Receivers
In this paper, we propose an interference mitigation technique for non-coherent on-off keying (OOK) receivers with respect to co-channel interference source. If the interfering signal (undecipherable at the receiver) is greater or equal to the desired signal, no reception is possible. A method is presented that mitigates this effect by inserting a blank space during the transmission of binary `...
Adaptive Power Allocation for HARQ with Chase Combining in Correlated Rayleigh Fading Channels
We consider the problem of minimizing the packet drop probability (PDP) under an average transmit power constraint for Chase combining (CC)-based hybrid-automatic repeat request (HARQ) schemes in correlated Rayleigh fading channels. We propose a method to find a solution to the non-convex optimization problem using an exact expression of the outage probability. However, the complexity of this m...
Joint Transmission Mode Selection and Scheduling in LTE Downlink MIMO Systems
In this article, we investigate multiple-input multiple-output (MIMO) transmission mode selection and scheduling for LTE downlink with users of different mobilities. Our algorithm first classifies users into high- and low-mobility ones, then selects open-loop spatial multiplexing (OLSM) or close-loop spatial multiplexing (CLSM) mode based on user's mobility, and finally assigns the time-frequen...