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The performance evaluation of control channels is very important, since the efficient signaling is critical to support the user data transmission in wireless communication. In the third generation (3G) Long Term Evolution-Advanced (LTE-Advanced) system, control channels are particularly studied and designed. In this paper, an introduction of downlink physical control channels in LTE-Advanced system...
Since the Quality of Experience (QoE) metric directly reflects the subjective experiences of users, the resource allocation techniques with the objective to improve QoE instead of conventional metrics are efficient in resource utilization. This kind of techniques can avoid wasting resources in providing perfect objective metric which may have little or even no effect on user experience. This paper...
Research on smart antenna has been incorporated in the evolution path from TD-SCDMA to TD-LTE. To reduce the array size of the mono-polarized smart antenna in TD-SCDMA systems, dual-polarization scheme is considered to facilitate the application of smart antenna in TD-LTE systems. In this paper, we investigate the performance degradation due to dual-polarization for smart antenna in TD-LTE system...
In multiuser cognitive radio (CR) network, we address the problem of joint transmit beamforming (BF) and power control (PC) for secondary users (SUs) when they are allowed to transmit simultaneously with primary users (PUs). The objective is to optimize the network sum rate under the interference constraints of PUs. Second-order cone programming approximation (SOCPA) method is proposed as an effective...
Overload indicator (OI) and high interference indicator (HII) are two main approaches to mitigate inter-cell interference in long term evolution (LTE) system. Using OI or HII separately will incur inevitable shortcomings, therefore, in this paper, an OI&HII hybrid scheme is proposed for inter-cell interference coordination (ICIC) through signaling interaction between the two schemes. Instead of...
Cognitive radio makes it possible for an unlicensed user to access a spectrum opportunistically. This paper addresses the problem of assigning subcarriers and bits in uplink for OFDMA-based cognitive radio networks. The objective is to maximize the system throughput in the presence of interference temperature constraint. In this paper, an adaptive bit loading algorithm is proposed first, which converges...
In cooperative systems, the fractional incremental relaying (FIR) protocol can achieve higher spectral efficiency than the traditional incremental relaying (IRL) protocol by transmitting a fraction of packet, instead of the whole packet, at a time when retransmission is needed. The incremental redundancy (IRD) protocol can also be utilized when retransmission is necessary. Based on the two protocols,...
This paper studies the performance of Voice-over-Internet-Protocol (VoIP) service in the third generation (3G) long-term evolution (LTE)-Advanced relaying networks. We propose a semi-persistent scheduling algorithm for the VoIP service in the LTE-Advanced relaying networks. The performance of the presented algorithm is verified by system-level simulation. Deployments with different number of relay...
Similar to its frequency division duplex (FDD) counterpart, there is currently great interest in introducing multiple-input multiple-output (MIMO) antenna technique into time division-synchronized code division multiple access (TD-SCDMA) high-speed packet access evolution (HSPA+) system within 3GPP. To this end, per-antenna rate control (PARC), selective-PARC (S-PARC) and dual-stream transmit antenna...
In this paper, the optimal relay station (RS) location and the bandwidth allocation for RS in fixed RS based radio cooperation system are investigated to maximize the data rate when the RS adopts decode-amplify-forward (DAF) scheme. According to the information-theoretic achievable rate maximization policy, the MS selectively accesses base station (BS) or RS, and the optimal RS location is obtained...
In MIMO multi-relay systems, close-loop precoding at relay nodes is not necessary if unicast modes are carried out. However, in unicast modes, the inter-stream interference at relay nodes may degrade the system capacity. In this paper, two unicast modes are proposed to reduce the negative impact of the residual interference. The first one suppresses the interference by applying orthogonal precoding...
The end-to-end throughput of a route in Cognitive Radio Network (CRN) is related to three factors: rate of links which consist of the route, channel diversity in the route and the primary usage pattern. In this paper, we considered all these factors together. Firstly, we analyzed the capacity of the individual CR link after considering the primary usage pattern. Then, we carefully investigated the...
In this paper, we investigated the end-to-end throughput of a chain in Cognitive Radio Networks (CRNs). We found that, the end-to-end throughput is dependant on both the primary usage patterns and the transmission scheduling scheme being used. In addition, to increase the end-to-end throughput of a Cognitive Radio (CR) chain, the scheduling scheme should be adjusted according to the primary usage...
Network coding is seen as a promising technique to improve network throughput. In this paper, network coding in cooperative relay networks and user cooperative networks is investigated and an optimized power allocation scheme is provided. By comparing with traditional relay forwarding in a simple two-user scenario, network coding shows a better system performance with a lower hardware cost and higher...
In this paper, the results of the quality of service for VoIP service over TD-SCDMA HSDPA system are presented. The performances of the system with different scheduling algorithms and different retransmission times are simulated and analyzed. Dynamic scheduling, adaptive modulation and code (AMC), dynamic HARQ are implemented in the system-level simulation and some recommends for HARQ channel number...
Statistical method was employed to study and describe the structure characteristics of natural fibers in this paper due to their non-uniform, irregular and composite structures. Two types of fiber surface treatment methods, namely chemical bonding and oxidization were used to improve the interfacial bonding properties of natural fiber reinforced polymeric composites. Interfacial properties were evaluated...
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