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In this paper, we consider an extension of the cognitive radio channel model in which the secondary transmitter has to obtain (learn) the primary message rather than having non-causal knowledge of it. We formulate an achievable rate region that combines elements of compress-and-forward relaying with coding for the pure cognitive radio channel model. Moreover, we provide parameters design that maximizes...
Polyphase magnitude modulation (MM) has been shown to be a robust and effortless mean to improve the efficiency of a transmitter's high power amplifier (HPA), due to the real-time reduction of the peak to average power ratio (PAPR). MM's technique flexibility allows us to include the MM system on any existing single-carrier (SC) based transmission system with clear benefits on the achieved bit error...
Non-orthogonal multiple access improves spectral efficiency through sharing the same frequency resource with multiple wireless terminals. In previous researches, it has been shown that a log likelihood ratio (LLR) calculated from a signal on the sharing spectrum should be masked to zero if the power of an interference signal is stronger than that of a desired signal. This implies that the spectrum...
In this paper, we propose a dirty paper coding (DPC) scheme that uses trellis shaping for the overlay cognitive radio channel, where a cognitive user and a primary user transmit concurrently in the same spectrum. Interference of the primary user is assumed to be known at the cognitive transmitter non-causally. Based on this knowledge, the shaping code selection, as a key feature of the proposal, is...
In this paper, we derive an effective SINR mapping algorithm based on Mutual Information (MI) Effective SINR Metric (ESM) model for 256QAM modulation system. Since recently 256QAM modulation is proposed in 3GPP LTE-A Rel.12 and IEEE 802.11ac standard, the design of Link-to-System (L2S) interface for 256QAM needs to be considered. Based on the Log Likelihood Ratio (LLR) receiver model, we derive the...
Spectrum sharing for cognitive two-way relaying is considered in this paper. A secondary relay is used to assist two-way communications between two primary users, and as a return, the secondary relay is allowed to transmit its own secondary signal by using some of the licensed primary spectrum. Three different spectrum sharing strategies are studied in this paper. In the baseline superposition coding...
This paper proposes a new underlay cooperative cognitive radio system, where a paid cooperation between the primary and the secondary systems is allowed. We consider both decoding strategy at the secondary receiver and the power efficiency optimization problem, in order to maximize the rate of the cognitive system. The secondary user has to communicate to the receiver in the presence of primary transmission,...
The focus of this work is put on a cognitive network wherein the secondary users (SUs), based on bit-interleaved-coded orthogonal frequency division multiplexing, share the same band of primary users (PUs). In this context, we develop a distributed power allocation (PA) strategy which minimizes the coded packet error rate (PER) of the noncooperative SU links under the constraint of satisfying the...
This paper deals with the retransmission protocol design for cognitive radio networks by exploiting the primary hybrid ARQ. In contrast with previous work that focuses on cancellation based retransmissions, we propose a novel cooperative coding based retransmission protocol for cognitive radio networks. The design objective is to improve the throughput of the primary user and create the transmission...
Orthogonal Frequency Division Multiple Access (OFDMA) as well as other orthogonal multiple access techniques fail to achieve the system capacity limit in the uplink due to the exclusivity in resource allocation. This issue is more prominent when fairness among the users is considered in the system. Current Non-Orthogonal Multiple Access (NOMA) techniques introduce redundancy by coding/spreading to...
Network coded opportunistic routing (NCOR) is a potential communication paradigm in wireless multi-hop networks (WMN) with lossy links. It leverages the multipath diversity of wireless networks and applies network coding to resist random erasures. Related optimization work minimizing transmission cost or maximizing throughput are based on the collision-free assumption, which either requires perfect...
In Heterogeneous networks (HetNet), low-power Small Cells (SCs) can serve a good portion of the mobile users. These users are likely to have good Signal-to-Interference-plus-Noise-Ratio (SINR) values, which can be exploited to satisfy the expected demand of huge data rates. In this paper, we investigate the effect of introducing higher order modulation, mainly 256QAM, from a link-level perspective...
This paper is concerned with the design of distributed precoding in the multiple access (MA) phase for two-way relaying communication (TWRC) systems using OFDM. The error probability analysis is conducted to establish the diversity and coding gains for three error types in the MA phase. Then the design criteria of distributed precoding to achieve the maximum diversity and coding gains are given. The...
This paper studies the performance of adaptive modulation and coding in a cognitive incremental decode-and-forward relaying network where a secondary source can directly communicate with a secondary destination or via an intermediate relay. To maximize transmission efficiency, a policy which flexibly switches between the relaying and direct transmission is proposed. In particular, the transmission,...
The MAC-BC duality of information theory and wireless communications is an intriguing concept for efficient algorithm design. However, no concept is known so far for the important cellular channel. To make progress on this front, we consider in this paper the linear deterministic cellular channel. In particular, we prove duality of a network with two interfering MACs in each cell and a network with...
The problem of exact repair of a failed node in multi-hop networked distributed storage systems is considered. Contrary to the most of the current studies which model the repair process by the direct links from surviving nodes to the new node, the repair is modeled by considering the multi-hop network structure, and taking into account that there might not exist direct links from all the surviving...
The paradigm shift from an exclusive to a shared use of frequencies comes along with the necessity of new concepts since interference will be ubiquitous. Resulting channels may vary in an arbitrary and unknown manner from channel use to channel use. This is the arbitrarily varying channel (AVC). Here, coordination resources such as common randomness or correlated sources have been shown to be important...
Recent advances in information theory (IT) have shown great promises of interference alignment (IA) for cellular networks. However, due to a number of assumptions, these IT results cannot be directly applied to address practical problems. The goal of this paper is to fill in this gap by studying IA for cellular networks with more practical settings. We propose an IA scheme that includes constraints...
This paper investigates the error performance of a full-duplex (FD) amplify-and-forward (AF) single-relay system under the effect of residual self-interference whose variance is proportional to the λ-th power of the transmitted power (0≤λ ≤1). Our focus is on the cooperative FD linear relaying (LR) protocol that makes use of direct source-destination link. At first, a closed-form expression of the...
The promotion and application of PLC technology has been restricted by the power line's bad channel characteristics and noise distribution. In order to overcome these disadvantages and achieve more stable, secure and high speed level of communication, the writer designed a narrow-band high speed PLC communication platform based on G3-PLC. A FPGA was used to achieve the procedure of signal processing...
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