277,041 research outputs found
Serial Acquisition Performance of Single- and Multi-carrier DS-CDMA over Nakagami- Fading Channels
No full textMobile Social Networking aided content dissemination in heterogeneous networks
Get PDFSince more and more mobile applications are based on the proliferation of social information, the study of Mobile Social Net-works (MSNs) combines social sciences and wireless communications. Operating wireless networks more efficiently by exploiting social relationships between MSN users is an appealing but challenging option for network operators. An MSN-aided content dissemination technique is presented as a potential ex-tension of conventional cellular wireless net-works in order to satisfy growing data traffic. By allowing the MSN users to create a self-organized ad hoc network for spontaneously disseminating contents, the network operator may be able to reduce the operational costs and simultaneously achieve an improved network performance. In this paper, we first summarize the basic features of the MSN architecture, followed by a survey of the factors which may affect MSN-aided content dissemination. Using a case study, we demonstrate that one can save resources of the Base Station (BS) while substantially lowering content dissemination delay. Finally, other potential applications of MSN-aided content dissemination are introduced, and a range of future challenges are summarized
Non-Coherent Cooperative Communications Dispensing with Channel Estimation Relying on Erasure Insertion Aided Reed-Solomon Coded SFH M-ary FSK Subjected to Partial-Band Interference and Rayleigh Fading
No full textThe rationale of our design is that although much of the literature of cooperative systems assumes perfect coherent detection, the assumption of having any channel estimates at the relays imposes an unreasonable burden on the relay station. Hence, non-coherently detected Reed-Solomon (ReS) coded Slow Frequency Hopping (SFH) assisted M -ary Frequency Shift Keying (FSK) is proposed for cooperative wireless networks, subjected to both partial-band interference and Rayleigh fading. Erasure insertion (EI) assisted ReS decoding based on the joint maximum output-ratio threshold test (MO-RTT) is investigated in order to evaluate the attainable system performance. Compared to the conventional error-correction-only decoder, the EI scheme may achieve an Eb/N0 gain of approximately 3dB at the Codeword Error Probability, Pw , of 10-4 , when employing the ReS (31, 20) code combined with 32-FSK modulation. Additionally, we evaluated the system’s performance, when either equal gain combining (EGC) or selection combining (SC) techniques are employed at the destination’s receiver. The results demonstrated that in the presence of one and two assisting relays, the EGC scheme achieves gains of 1.5 dB and 1.0 dB at the Pw of 10-6 , respectively, compared to the SC arrangement. Furthermore, we demonstrated that for the same coding rate and packet size, the ReS (31, 20) code using EI decoding is capable of outperforming convolutional coding, when 32-FSK modulation is considered, whilst LDPC coding had an edge over the above two schemes
Alebroides spanner Yu & Yang, sp. nov.
No full textA. spanner Yu & Yang, sp. nov. Distribution. China (Guizhou).Published as part of Yu, Xiaofei & Yang, Maofa, 2014, Four new species of Alebroides Matsumura (Hemiptera: Cicadellidae: Typhlocybinae) from China, pp. 248-262 in Zootaxa 3780 (2) on page 252, DOI: 10.11646/zootaxa.3780.2.2, http://zenodo.org/record/23041
Alebroides strumae Yu & Yang, sp. nov.
No full textA. strumae Yu & Yang, sp. nov. Distribution. China (Tibet).Published as part of Yu, Xiaofei & Yang, Maofa, 2014, Four new species of Alebroides Matsumura (Hemiptera: Cicadellidae: Typhlocybinae) from China, pp. 248-262 in Zootaxa 3780 (2) on page 252, DOI: 10.11646/zootaxa.3780.2.2, http://zenodo.org/record/23041
Alebroides chiasmaticus Yu & Yang, sp. nov.
No full textA. chiasmaticus Yu & Yang, sp. nov. Distribution. China (Guangxi).Published as part of Yu, Xiaofei & Yang, Maofa, 2014, Four new species of Alebroides Matsumura (Hemiptera: Cicadellidae: Typhlocybinae) from China, pp. 248-262 in Zootaxa 3780 (2) on page 251, DOI: 10.11646/zootaxa.3780.2.2, http://zenodo.org/record/23041
Wang Cheng-li, Bohai Jianshi, Li Dian-fu & Sun Yu-liang, Bohai guo Yang Bao-long, Bohai-shi rumen
No full textYonglip Joo. Wang Cheng-li, Bohai Jianshi, Li Dian-fu & Sun Yu-liang, Bohai guo Yang Bao-long, Bohai-shi rumen. In: Cahiers d'Extrême-Asie, vol. 6, 1991. Numéro spécial Chamanisme coréen - Special Issue on Korean Shamanism. pp. 311-313
Cong liang zi xin xi xue de jiao du tan tao yi xie liang zi xiang bian zhong de ji ben wen ti
No full textYu, Wing Chi = 從量子信息學的角度探討一些量子相變中的基本問題 / 余詠芝.Thesis Ph.D. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 131-139).Abstracts also in Chinese.Title from PDF title page (viewed on 03, November, 2016).Yu, Wing Chi = Cong liang zi xin xi xue de jiao du tan tao yi xie liang zi xiang bian zhong de ji ben wen ti / Yu Yongzhi
Capacity and Error Performance of Reduced-Rank Transmitter Multiuser Preprocessing Based on Minimum Power Distortionless Response
No full textIn this contribution we first derive a transmitter multiuser preprocessing (TMP) scheme for a general multiuser multiple-input-multiple-output (MIMO) system based on the minimum power distortionless response (MPDR) criterion, which minimizes the power in the context of a given downlink mobile terminal (MT) under the distortionless condition. This optimization problem results in a solution, which has the same form as the minimum mean-square error (MMSE) multiuser detection (MUD). Hence, we then extend the well-known rank-reduction techniques in MMSE-MUD to the MPDR-TMP in order to mitigate the possible implementation problems of the MPDRTMP. In our study three classes of rank-reduction algorithms are considered, which are derived, respectively, based on the eigen-analysis methods of principal components (PC) and crossspectral metrics (CSMs) as well as on the Taylor polynomial approximation (TPA) approach, which does not depend on the eigen-analysis. In this contribution both the capacity and error performance of a downlink space-division multiple-access (SDMA) system is investigated, when either the full-rank or reduced-rank MPDR-TMP is invoked. From our study and simulation results, it can be shown that the MPDR-TMP scheme is highly efficient for achieving the capacity and for suppressing the multiuser interference (MUI). The reduced-rank techniques can be employed by the MPDR-TMP, so as to reduce its implementation complexity while achieving the near full-rank performance of the full-rank MPDR-TMP
Liang du yu zhou she xian ji yan zhi li zi tan ce qi
No full textLeung, Shing Chau = 量度宇宙射線及研製粒子探測器 / 梁乘宙.Thesis M.Phil. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 125-131).Abstracts also in Chinese.Title from PDF title page (viewed on 20, December, 2016).Leung, Shing Chau = Liang du yu zhou she xian ji yan zhi li zi tan ce qi / Liang Chengzhou
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