Nicholas Watt Chief Ireland Correspondent, Phil Yates, Michael Hull (Professor), Doreen Davie, Nick Nuttall, Bel Mooney, Taleban, Zahid Hussain, B. J. Hopkinson, Mike John, Rob Hughes, James Bone, Correspondent, Magnus Linklater, Sara McConnell and Marianne Curphey, Bill Frost, Richard Thomson, Joanna Bale, Jason Nisse, Andrew Pierce and Kathryn Knight, Inigo Gilmore, Janet Bush, Economics Correspondent, Valerie Elliott Editor, Harvey Elliott, Philip Howard, Alice Thomson and Jill Sherman, Arthur Leathley and Audrey Magee, Carol Midgley, Hilary Finch, Diana Mosley, Jeremy Kingston, James Bone, Lynne Truss, Carl Mortished, Richard Eaton, Morag Preston, Nigel L. Denton, Geoff Brown, Robert Sheehan, Bridge Correspondent, Nicholas Henderson, Robert Miller, David Levaggi, Arthur Leathley Political Correspondent, Martin Fletcher, Harvey Elliott and Tony Dawe, John Bryant, Morag Perston, John Hopkins, Golf Correspondent, David Charter Education Correspondent, Peter Ball, Jason Nissé and Andrew Pierce, Shirley English, Alice Thomson Political Reporter, Raymond Keene Chess Correspondent, Rob Hughes Football Correspondent, Richard Ford Home Correspondent, Richard Need, Alan Hamilton, David Dabydeen, Jill Sherman Chief Political Correspondent, Robert Bruce, Michael Clark, Norman Lamont, Philip Randall and IsobelSharp, Quentin Letts, Charles Bremner, Joseph Connolly, Woodrow Wyatt, Peter Barnard, Noel Fung, Roger Scruton, Russell Kempson, G. Pattie (Chairman), David Hands, Correspondent, David Charter and Paul Wilkinson, Paul Durman, Rachel Bridge, Emma Wilkins and Alan Hamilton, Marit Hargie, David Miller, Barry Millington, Anthony Chamier, John Higgins, Thomas Pakenham, Marcus Binney, Raymond Keene, Robin Young and Adam Fresco, Emma Wilkins, Frances Gibb, Legal Correspondent, P. H. S, Caroline Merrell, Sunjay Kakar, Bronwen Maddox, George Bull, Richard Owen, Damian Whitworth, Jonathan Ward, Sarah Cunningham, Nigel Hawkes, Science Editor, Dominic Kennedy Social Affairs Correspondent, Oliver August, Michael Hornsby, Agriculture Correspondent, Julian Muscat, Richard Duce, Barbara Mills Director, Christopher Thomas, Jack Crossley, Philip Webster Political Editor, Sara McConnell, Christopher Walker, Gary Rawlinson, David Jefferies, Jason Nissé, Mel Webb, Des Dearlove, Srikumar Sen Boxing Correspondent, Denis Conlon (Managing Director), Matthew Parris, William Fiennes, John Shaw, Keith Blackmore, Peter Riddell, Ben MacIntyre, Richard Beeston, Brian Glanville, Michael Dynes, Simon Jenkins, Fraser Nelson, Dr Thomas Stuttaford, Marianne Curphey, Frances Gibb Legal Correspondent, Richard Morrison, Sam Kiley, David Maddock, Michael Evans, Harvey Elliott Air Correspondent, Mark Fuller, Jonathan Holborow Editor, Edward Gorman Sailing Correspondent, James Willoughby, Richard Ford, Robert Tomkinson, Jonathan Mirsky, Christopher Irvine, Christine Buckley, Industrial Correspondent, Edward Little,
... plc Management & Training Consultancy Opportunities The Dorow Partnership CDMA PCN GSM The Consultancy Company Melville Craig Group ...
1996 - Gale Group | TDA
Wang Xiang, Xiqing Liu, Hsiao‐Hwa Chen, Weixiao Meng,
In a frequency division complementary coded CDMA (FD-CC-CDMA) system, multiple tuners have to be used for multi-carrier modulation, which has a very high complexity and power ... implement multi-carrier modulation in an FD-CC-CDMA system, which is named as CP-free OFDM-CC-CDMA system. The transmitter in the CP-free OFDM-CC-CDMA system offers a unique flexibility to adjust the ... the receiver of a CP-free OFDM-CC-CDMA system, minimum mean square error (MMSE) equalization and ... results show that a CP-free OFDM-CC-CDMA system offers a much higher transmission efficiency than ...
Tópico(s): Advanced Wireless Communication Technologies
2020 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Vehicular Technology
Ho‐Hsuan Chang, Shieh-Chiang Lin, Chong‐Dao Lee,
... PN) code in the code division multiple access (CDMA) scheme to enable distinct users to simultaneously share ... a common channel, which is called direct sequence CDMA (DS-CDMA). However, this scheme does not provide the required ... a new perfect Gaussian integer sequence (PGIS)-based CDMA scheme called PGIS-CDMA; in this scheme, the PN code of DS-CDMA is replaced by a set of PGISs. The ... property of PGIS can be applied to a CDMA system to achieve perfect cochannel interference separability under ... concepts are further developed to implement two PGIS-CDMA configurations, and they can outperform DS-CDMA on ...
Tópico(s): Coding theory and cryptography
2017 - Elsevier BV | AEU - International Journal of Electronics and Communications
Kun Wang, Jin He, Ting Shu, Zhong Liu,
... angle and delay estimation for underwater acoustic multicarrier CDMA systems using a vector sensor Kun Wang, Kun ... angle and delay estimation for underwater acoustic multicarrier CDMA systems using a vector sensor is addressed. By ... underwater acoustic multicarrier code-division multiple access (MC-CDMA) systems using a single vector sensor. We first ... vector-sensor (TEVES) response vector for the MC-CDMA signals. Then, the subcarrier information is used to ... Consider an underwater acoustic system with K MC-CDMA transmitted signals and a four-component receive vector ...
Tópico(s): Radar Systems and Signal Processing
2016 - Institution of Engineering and Technology | IET Radar Sonar & Navigation
Low-density signature code division multiple access (LDS-CDMA) and low-density parity-check (LDPC) code can ... graph (JSG) over GF(q) which combines LDS-CDMA and non-binary LDPC codes, namely JSG-CDMA. On the JSG, multiple accessing and channel coding ... they depict the iterative structure of the JSG-CDMA receiver and analyse its extrinsic information transfer chart. Key factors of JSG-CDMA include message passing schedule, maximum iteration number and Galois field order. Simulation results show that JSG-CDMA performs much better than conventional CDMA, in addition, ...
Tópico(s): Cooperative Communication and Network Coding
2015 - Institution of Engineering and Technology | IET Communications
Nazila Rahnama, Siamak Talebi,
... conventional direct-sequence-code division multiple access (DS-CDMA)-based solutions have been put forward that deals ... approach that employs a chaotic sequence in DS-CDMA system over fading channels. The proposed algorithm, which ... in direct sequence-code division multiple access (DS-CDMA) systems. In this model, a perfect synchronisation between ... and then in Section 3 chaos-based DS-CDMA system is covered followed by an overview of ... 4, probability of error of chaos-based DS-CDMA system is fully explored. The next section presents ...
Tópico(s): Chaos-based Image/Signal Encryption
2013 - Institution of Engineering and Technology | IET Communications
National Library of Medicine (NCBI)
Jun‐Da Chen, Fang‐Biau Ueng, Jui‐Chi Chang, Hsien Su,
... combination of OFDM and code-division multiple access (CDMA) which is referred to as OFDM–CDMA, has recently attracted much research interest in wireless ... downlink performance for two forms of adaptive OFDM–CDMA receivers in multipath fading channels: 1) MC–CDMA and 2) MC–direct sequence (DS)–CDMA. We propose theoretical minimum mean square errors (MMSEs) for MC–CDMA and MC–DS–CDMA to compare the performances in different situations. Moreover, ... significantly affects the channel utilization in MC–DS–CDMA systems. We propose adaptive receiver structures with both ...
Tópico(s): Advanced Wireless Network Optimization
2009 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Vehicular Technology
... capacity direct-sequence code-division multiple-access (DS-CDMA) wireless communication system, where numerous antennas are distributed ... system, typical characteristics of the distributed-antenna DS-CDMA (DA/DS-CDMA) system are summarized, in comparison with conventional DS-CDMA systems that employ centralized base station (BS) antennas. ... error rate (BER) performance of the DA/DS-CDMA system without using power control is investigated when ... and numerical results suggest that the DA/DS-CDMA system constitutes a high-power-efficiency wireless system. ...
Tópico(s): Cooperative Communication and Network Coding
2008 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Vehicular Technology
Wan Choi, Jeffrey G. Andrews, Robert W. Heath,
Improving the capacity of code-division-multiple-access (CDMA) systems through advanced signal processing has been an ... particularly, downlink capacity. Nearly all research on MIMO-CDMA, however, has focused on increasing the throughput achieved ... consider the downlink of a heavily loaded multicell CDMA system with multiple transmit and receive antennas. Straightforward ... supportable users. To overcome this, a novel MIMO-CDMA system design based on user partitioning is developed, ... and would require only small changes to existing CDMA standards. The outage probability and capacity of the ...
Tópico(s): Advanced MIMO Systems Optimization
2007 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Vehicular Technology
IEEE Xplore
... basic aspects of Code Division Multiple Access or CDMA. It begins with an introduction to the basic ... systems in order to demonstrate the difference between CDMA and the more widely understood TDMA, FDMA or ... spectrum techniques are presented which are used in CDMA systems including direct sequence, frequency-hopping and time-hopping approaches. The basic concept of CDMA is presented, followed by the four basic principles of CDMA systems that impact their performance: interference averaging, universal ...
Tópico(s): Wireless Networks and Protocols
2006 - Morgan & Claypool Publishers | Synthesis lectures on communications
Hsiao‐Hwa Chen, Yang Xiao, Jie Li, Romano Fantacci,
... paper starts with a review of 2G-3G CDMA based wireless systems from a network operation perspective. In particular, the challenges faced by current CDMA technologies will be addressed with the focus on ... with and without infrastructure, will make all current CDMA technologies unsuitable due to their rigid and voice- ... layer architecture. To respond to the call for CDMA innovation, a novel OCC-CDMA/OS physical layer architecture is proposed in this ... One of the most important features of OCC-CDMA/OS physical layer architecture is its unique elasticity, ...
Tópico(s): Advanced Wireless Communication Techniques
2006 - Institute of Electrical and Electronics Engineers | IEEE Vehicular Technology Magazine
Nalin S. Weerasinghe, Takeshi Hasimoto,
... downlink direct-sequence code-division multiple access (DS-CDMA), we introduce a cyclic-prefix (CP)-based convolutional spreading CDMA (CS-CDMA/CP) scheme employing zero correlation zone (ZCZ) codes, ... gives a class of multiuser interference (MUI)-free CDMA schemes, including Suehiro's CDMA and block spreading (BS) CDMA as special cases. We show that CS-CDMA/CP employing appropriately selected binary and ternary ZCZ ...
Tópico(s): PAPR reduction in OFDM
2006 - IEEE Communications Society | IEEE Transactions on Communications
Hsiao‐Hwa Chen, Hsin‐Wei Chiu, Mohsen Guizani,
This article addresses the issues of next-generation CDMA technologies for B3G wireless communications. To engineer a CDMA system whose performance will no longer be interference- ... challenging issues should be tackled, such as novel CDMA code sets, efficient spreading and carrier modulation schemes, ... article reviews our ongoing research on next-generation CDMA technologies. In particular, we propose a new CDMA code design methodology, real environment adapted linearization (REAL), which can generate CDMA code sets with inherent immunity against multipath interference ...
Tópico(s): Advanced Wireless Communication Techniques
2006 - Institute of Electrical and Electronics Engineers | IEEE Wireless Communications
Deepshikha Garg, Fumiyuki Adachi,
OFDM, MC-CDMA and DS-CDMA are being researched vigorously as the prospective signaling technique for the next generation mobile communications systems, which will be characterized by ... the OFDM system can be attained with MC-CDMA and DS-CDMA by assigning all the available codes to the ... what is commonly referred to as multicode MC-CDMA and multicode DS-CDMA. A rake receiver is used for receiving the DS-CDMA signals. However, recently minimum mean square error frequency- ... has been proposed for the reception of DS-CDMA signals. In this paper, we introduce RCPT HARQ ...
Tópico(s): PAPR reduction in OFDM
2005 - Institute of Electronics, Information and Communication Engineers | IEICE Transactions on Communications
Code division multiple access (CDMA) is based on the spread-spectrum technology and is a dominant air interface for 2.5G, 3G, and future wireless networks. For the CDMA downlink, the transmitted CDMA signals from the base station (BS) propagate through ... the user equipment/mobile station (UE/MS). Classical CDMA single-user detection (SUD) algorithms implemented in the ... all the users in the downlink of a CDMA communication system using only the received wireless data ... user spreading codes. This approach is applicable to CDMA systems with relatively short spreading codes but becomes ...
Tópico(s): Advanced Wireless Communication Techniques
2005 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Neural Networks
... direct-sequence (DS) code-division multiple access (BIDS-CDMA) and the more recently proposed chip-interleaved DS-CDMA (CIDS-CDMA), both with channel coding. Simple CIDS-CDMA treats a set of bits at a time ... on top of chip interleaving (thus abbreviated BCIDS-CDMA) to enhance performance. For simplicity, we first tackle ... for the various conditions above. In general, BCIDS-CDMA performs best, followed by simple CIDS-CDMA and then by BIDS-CDMA. Within simple CIDS-CDMA and BIDS-CDMA, long-code spreading performs better ...
Tópico(s): Advanced Wireless Network Optimization
2005 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Vehicular Technology
Multi-carrier code division multiple access (MC-CDMA) demonstrates good probability of error performances in frequency selective fading channels, a direct result of its ability to resolve the available frequency diversity. However, MC-CDMA performances may be limited by degradation due to ... multi-carrier code division multiple access (FD-MC-CDMA), a novel multiple access architecture proposed in this ... users' information bits over all carriers, FD-MC-CDMA employs a subset of carriers to support a ... overall system capacity and throughput as in MC-CDMA). By careful selection of each subset of carriers, ...
Tópico(s): Satellite Communication Systems
2005 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Vehicular Technology
Deepshikha Garg, Fumiyuki Adachi,
MC-CDMA, a multicarrier (MC) modulation scheme based on code division multiple access (CDMA), is the most likely candidate for the next ... improved throughput performance in a direct sequence (DS) CDMA system. However, the extent to which the RCPT HARQ improves the throughput performance of an MC-CDMA system has not been fully understood. In this paper, we apply the RCPT HARQ to MC-CDMA and evaluate by computer simulations its performance in ... found that the performance of RCPT HARQ MC-CDMA is almost insensitive to channel characteristics. The performance ...
Tópico(s): Advanced Wireless Network Optimization
2004 - Electronics and Telecommunications Research Institute | ETRI Journal
Mahrokh G. Shayesteh, Jawad A. Salehi, Masoumeh Nasiri‐Kenari,
... of spread-time/code division multiple access (ST/CDMA). We consider two different models for fading channel ... to interference plus noise ratio (SIR) for ST/CDMA in both cases. We also obtain the SIR for spread-spectrum/CDMA (SS/CDMA) and compare the results with that of ST/CDMA. Depending upon the transmitted chip pulse shape, and ... greater than spread spectrum (SS). For example ST/CDMA has 0.62 dB higher SIR value compared to SS/CDMA with root raised cosine pulse shape with rolloff factor 0.22 used in W-CDMA. The spread-time technique was first proposed by ...
Tópico(s): Advanced Wireless Communication Techniques
2003 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Wireless Communications
... division multiple access schemes: single-carrier direct-sequence CDMA (SC DS-CDMA), multicarrier CDMA (MC-CDMA), and multicarrier DS-CDMA (MC DS-CDMA). Specifically, their benefits and deficiencies are analyzed when ... communicating in such diverse environments, both SC DS-CDMA and MC-CDMA exhibit certain limitations that are hard to circumvent. ...
Tópico(s): Advanced Wireless Network Optimization
2003 - Institute of Electrical and Electronics Engineers | IEEE Communications Magazine