ZTE provides customized CDMA WLL solutions that can bring youvalue-added services under any circumstances.Flexibility:Flexible network solutions for both urban and rural areas.Expertise:Cost-effective solutions based ...ZTE provides customized CDMA WLL solutions that can bring youvalue-added services under any circumstances.Flexibility:Flexible network solutions for both urban and rural areas.Expertise:Cost-effective solutions based on CDMA2000 technology,offering wireless data services, can easily evolve to 3G.Experience:Proven technology with 90% market share in China aswell as applications in overseas countries like India and Brazil.展开更多
The technical solutions to the convergence of WLAN and CDMA 2000 1x are presented and compared.Problems brought on by network convergence are analyzed,and solutions to problems such as the coexistence of packet data s...The technical solutions to the convergence of WLAN and CDMA 2000 1x are presented and compared.Problems brought on by network convergence are analyzed,and solutions to problems such as the coexistence of packet data service nodes(PDSNs),user i- dentification,roaming,and handoff are discussed in detail.展开更多
Based on the analysis on features of WLAN and CDMA2000 1x.the paper details ZTE's solution to the convergence.of WLAN and CD- MA2000 1x from the perspectives of network architecture and sys- tem components,and ana...Based on the analysis on features of WLAN and CDMA2000 1x.the paper details ZTE's solution to the convergence.of WLAN and CD- MA2000 1x from the perspectives of network architecture and sys- tem components,and analyzes the advantages of the scheme,and presents application by Shanghai Unicom.展开更多
ZTE Corporation (ZTE),a leading global provider of telecommunications equipment and network solutions,announced,on February 24,2009,another technological breakthrough by achieving the world’s first EV-DO Revision B (...ZTE Corporation (ZTE),a leading global provider of telecommunications equipment and network solutions,announced,on February 24,2009,another technological breakthrough by achieving the world’s first EV-DO Revision B (Rev.B)展开更多
At ITU Telecom Africa 2004,Telecom Egyptofficially announced that it had selected ZTECorporation,the leading telecom solutionsprovider in the world,to be its global strategicpartner,and that ZTE would undertake thecon...At ITU Telecom Africa 2004,Telecom Egyptofficially announced that it had selected ZTECorporation,the leading telecom solutionsprovider in the world,to be its global strategicpartner,and that ZTE would undertake theconstruction of its CDMA WLL network anddeliver full services to Telecom Egypt.Akil Beshir,Chairman of Telecom展开更多
Since the Ministry of Information Industry promulgated the Third Generation (3G) mobile communication "China Standard" TD-SCDMA as the standard for China's communication industry, the ministry has al... Since the Ministry of Information Industry promulgated the Third Generation (3G) mobile communication "China Standard" TD-SCDMA as the standard for China's communication industry, the ministry has also promulgated WCDMA and CDMA2000 as industrial standards.……展开更多
This paper reports the implementation and theoretical model for analyzing an optical CDMA/DWDM hybrid system to reduce two major problems,the Inter-Symbol Interference(ISI)and the Four-Wave Mixing(FWM)effects and impr...This paper reports the implementation and theoretical model for analyzing an optical CDMA/DWDM hybrid system to reduce two major problems,the Inter-Symbol Interference(ISI)and the Four-Wave Mixing(FWM)effects and improve the performance of optical subscriber access networks by using Zero Cross-Correlation(ZCC)optical codes,which helps to reduce the effect of the Multiple Access Interference(MAI).A squeezing method is used in the proposed hybrid system to completely suppress the ISI.In this method,the sequence interval of the signature code is squeezed into a duration of less than one-bit.The hybrid system is capable of accommodating 120 optical CDMA users carried by only 10 DWDM wavelengths spaced by 0.2 nm with 60 Gb/s/wavelength transmitted over 105.075 km of optical fiber.The result shows that the optimum interval of the code sequence is a quarter(i.e.,25%)of the bit duration.Moreover,the results reveal that the CDMA technology based on the spread spectrum is capable of increasing the nonlinear tolerance of the proposed hybrid system as the energy of bits is distributed over the chip sequence code.Also,the number of ones/weight and the positions between them have a significant effect on the performance of the proposed hybrid system.展开更多
A novel method is proposed to analyze the capacity of future Code Division Multiple Access (CDMA) systems carrying multimedia services. The power level allocation is firstly investigated to meet each call’s Bit Error...A novel method is proposed to analyze the capacity of future Code Division Multiple Access (CDMA) systems carrying multimedia services. The power level allocation is firstly investigated to meet each call’s Bit Error Rate (BER) requirement, then the system capacity is defined from the conditions for the exis-tence of the physical meaning of these power levels. Simulation results have shown that the capacity analyzing methods can be well used in the performance evaluation of the system accommodating heterogeneous services and the spectral efficiency of this scheme is higher than the existing ones.展开更多
The characteristics of underwater acoustic channel such as long propagation delay and low bit rate cause the MAC(Medium Access Control) protocols designed for radio channels to be either inapplicable,or have low effic...The characteristics of underwater acoustic channel such as long propagation delay and low bit rate cause the MAC(Medium Access Control) protocols designed for radio channels to be either inapplicable,or have low efficiency for UWSN(Underwater Sensor Network).We propose a hierarchical and distributed code assignment algorithm based on divisive probability function which can avoid conflict between spread codes with high probability,and provide a statebased MAC protocol for UWSN.Without RTS/CTS(Request To Send/Clear To Send) handshaking,each node maintains a neighbor table including state field,and packages are forwarded according to the state of the receiver,so it can avoid the interference caused by transmitting to a sending node in a half-duplex system and improve channel utilization.The design of power control minimizes the nearfar effect inherent in CDMA.Simulation results reveal that state-based CDMA protocol shows outstanding performance in throughput,delivery ratio and resource-consumption.展开更多
In CDMA communication systems, all the subscribers share the common channel. The limitation factor on the system’s capacity is not the bandwidth, but multiuser interference and the near far problem. This paper models...In CDMA communication systems, all the subscribers share the common channel. The limitation factor on the system’s capacity is not the bandwidth, but multiuser interference and the near far problem. This paper models CDMA system from the perspective of mobile radio channels corrupted by additive white noise generated by multipath and multiple access interferences. The system’s receiver is assisted using different combining diversity techniques. Performance analysis of the system with these detection techniques is presented. The paper demonstrates that combining diversity techniques in the system’s receivers markedly improve the performance of CDMA systems.展开更多
The interference reduction capability of cell sectoring and power control algorithms have been considered separately as means to decrease the interference in Code Division Multiple Access (CDMA) cellular systems. In t...The interference reduction capability of cell sectoring and power control algorithms have been considered separately as means to decrease the interference in Code Division Multiple Access (CDMA) cellular systems. In this paper, we present Switched-Beam (SB) and Rotatable Equal Sectoring (RES) techniques for CDMA cellular systems in a 2D urban environment. In the SB technique by using a number of fixed, independent, or directional antennas we increase the downlink capacity of the CDMA systems. Also in the RES method, the equal sectors of the base stations are rotating together to decrease the inter-cell and intra-cell interferences. Also in this paper we use centralized power control to overcome the near-far problem. Simulation results indicate that the proposed techniques considerably increase the capacity of the CDMA cellular systems compared to ordinary Equal Sectoring (ES) method.展开更多
In CDMA mobile communication systems, multiple access interference can be canceled by multiuser detection technique. The Degradation by channel fading can be reduced by diversity reception. This paper investigates a f...In CDMA mobile communication systems, multiple access interference can be canceled by multiuser detection technique. The Degradation by channel fading can be reduced by diversity reception. This paper investigates a family of multiuser receivers that combined decor-relating detection, antenna diversity and RAKE multipath diversity. The performance of the multiuser receivers is analyzed. The results demonstrate a significant increase in the performance of the receivers by using multiuser detection and diversity reception.展开更多
Throughput of mobile ad hoc network （MANET） is limited by collision avoidance. In CDMA-based MANET, this limitation can be overcome by multiuser detection （MUD） because conventional colliding packets can be detach...Throughput of mobile ad hoc network （MANET） is limited by collision avoidance. In CDMA-based MANET, this limitation can be overcome by multiuser detection （MUD） because conventional colliding packets can be detached and detected by MUD so that multi-packet reception （MPR） is possible. This paper introduces the principles of MUD algorithm for MANET, and proposes an adaptive blind MUD algorithm. A special medium access control （MAC） protocol is designed to make MANET more efficient. This is achieved by sending more packets to a destination simultaneously. The proposed MUD algorithm and MAC protocol allow CDMA-based MANET to support MPR. Simulations show a remarkable improvement in the throughput performance of MANET.展开更多
In this paper, an uplink power control problem is considered for code division multiple access （CDMA） systems. A distributed algorithm is proposed based on linear quadratic optimal control theory. The proposed schem...In this paper, an uplink power control problem is considered for code division multiple access （CDMA） systems. A distributed algorithm is proposed based on linear quadratic optimal control theory. The proposed scheme minimizes the sum of the power and the error of signal-to-interference ratio （SIR）. A power controller is designed by constructing an optimization problem of a stochastic linear quadratic type in Krein space and solving a Kalman filter problem.展开更多
Two blind multiuser detection algorithms for antenna array in Code Division Multiple Access (CDMA) system which apply the linearly constrained condition to the Least Squares Constant Modulus Algorithm (LSCMA) are prop...Two blind multiuser detection algorithms for antenna array in Code Division Multiple Access (CDMA) system which apply the linearly constrained condition to the Least Squares Constant Modulus Algorithm (LSCMA) are proposed in this paper. One is the Linearly Constrained LSCMA (LC-LSCMA), the other is the Preprocessing LC-LSCMA (PLC-LSCMA). The two algorithms are compared with the conventional LSCMA. The results show that the two algorithms proposed in this paper are superior to the conventional LSCMA and the best one is PLC-LSCMA.展开更多
文摘ZTE provides customized CDMA WLL solutions that can bring youvalue-added services under any circumstances.Flexibility:Flexible network solutions for both urban and rural areas.Expertise:Cost-effective solutions based on CDMA2000 technology,offering wireless data services, can easily evolve to 3G.Experience:Proven technology with 90% market share in China aswell as applications in overseas countries like India and Brazil.
文摘The technical solutions to the convergence of WLAN and CDMA 2000 1x are presented and compared.Problems brought on by network convergence are analyzed,and solutions to problems such as the coexistence of packet data service nodes(PDSNs),user i- dentification,roaming,and handoff are discussed in detail.
文摘Based on the analysis on features of WLAN and CDMA2000 1x.the paper details ZTE's solution to the convergence.of WLAN and CD- MA2000 1x from the perspectives of network architecture and sys- tem components,and analyzes the advantages of the scheme,and presents application by Shanghai Unicom.
文摘ZTE Corporation (ZTE),a leading global provider of telecommunications equipment and network solutions,announced,on February 24,2009,another technological breakthrough by achieving the world’s first EV-DO Revision B (Rev.B)
文摘At ITU Telecom Africa 2004,Telecom Egyptofficially announced that it had selected ZTECorporation,the leading telecom solutionsprovider in the world,to be its global strategicpartner,and that ZTE would undertake theconstruction of its CDMA WLL network anddeliver full services to Telecom Egypt.Akil Beshir,Chairman of Telecom
文摘 Since the Ministry of Information Industry promulgated the Third Generation (3G) mobile communication "China Standard" TD-SCDMA as the standard for China's communication industry, the ministry has also promulgated WCDMA and CDMA2000 as industrial standards.……
基金This work was supported by Multimedia University(Malaysia),project SAP ID:MMUI/160092.
文摘This paper reports the implementation and theoretical model for analyzing an optical CDMA/DWDM hybrid system to reduce two major problems,the Inter-Symbol Interference(ISI)and the Four-Wave Mixing(FWM)effects and improve the performance of optical subscriber access networks by using Zero Cross-Correlation(ZCC)optical codes,which helps to reduce the effect of the Multiple Access Interference(MAI).A squeezing method is used in the proposed hybrid system to completely suppress the ISI.In this method,the sequence interval of the signature code is squeezed into a duration of less than one-bit.The hybrid system is capable of accommodating 120 optical CDMA users carried by only 10 DWDM wavelengths spaced by 0.2 nm with 60 Gb/s/wavelength transmitted over 105.075 km of optical fiber.The result shows that the optimum interval of the code sequence is a quarter(i.e.,25%)of the bit duration.Moreover,the results reveal that the CDMA technology based on the spread spectrum is capable of increasing the nonlinear tolerance of the proposed hybrid system as the energy of bits is distributed over the chip sequence code.Also,the number of ones/weight and the positions between them have a significant effect on the performance of the proposed hybrid system.
基金Supported by the open research fund of the National Mobile Communications Key Lab of the Southeast Uni-versity and by the Hong Kong Research Council.
文摘A novel method is proposed to analyze the capacity of future Code Division Multiple Access (CDMA) systems carrying multimedia services. The power level allocation is firstly investigated to meet each call’s Bit Error Rate (BER) requirement, then the system capacity is defined from the conditions for the exis-tence of the physical meaning of these power levels. Simulation results have shown that the capacity analyzing methods can be well used in the performance evaluation of the system accommodating heterogeneous services and the spectral efficiency of this scheme is higher than the existing ones.
基金supported by the Program for New Century Excellent Talents in University of China(NCET-11-1025)the NationalNatural Science Foundation of China(No.61162003,61163050,6126104)+1 种基金Qinghai office of science and technology(grant No.2012-Z-902)the Natural Science Foundation of Tianjin(No.10JCYBJC00600)
文摘The characteristics of underwater acoustic channel such as long propagation delay and low bit rate cause the MAC(Medium Access Control) protocols designed for radio channels to be either inapplicable,or have low efficiency for UWSN(Underwater Sensor Network).We propose a hierarchical and distributed code assignment algorithm based on divisive probability function which can avoid conflict between spread codes with high probability,and provide a statebased MAC protocol for UWSN.Without RTS/CTS(Request To Send/Clear To Send) handshaking,each node maintains a neighbor table including state field,and packages are forwarded according to the state of the receiver,so it can avoid the interference caused by transmitting to a sending node in a half-duplex system and improve channel utilization.The design of power control minimizes the nearfar effect inherent in CDMA.Simulation results reveal that state-based CDMA protocol shows outstanding performance in throughput,delivery ratio and resource-consumption.
文摘In CDMA communication systems, all the subscribers share the common channel. The limitation factor on the system’s capacity is not the bandwidth, but multiuser interference and the near far problem. This paper models CDMA system from the perspective of mobile radio channels corrupted by additive white noise generated by multipath and multiple access interferences. The system’s receiver is assisted using different combining diversity techniques. Performance analysis of the system with these detection techniques is presented. The paper demonstrates that combining diversity techniques in the system’s receivers markedly improve the performance of CDMA systems.
文摘The interference reduction capability of cell sectoring and power control algorithms have been considered separately as means to decrease the interference in Code Division Multiple Access (CDMA) cellular systems. In this paper, we present Switched-Beam (SB) and Rotatable Equal Sectoring (RES) techniques for CDMA cellular systems in a 2D urban environment. In the SB technique by using a number of fixed, independent, or directional antennas we increase the downlink capacity of the CDMA systems. Also in the RES method, the equal sectors of the base stations are rotating together to decrease the inter-cell and intra-cell interferences. Also in this paper we use centralized power control to overcome the near-far problem. Simulation results indicate that the proposed techniques considerably increase the capacity of the CDMA cellular systems compared to ordinary Equal Sectoring (ES) method.
文摘In CDMA mobile communication systems, multiple access interference can be canceled by multiuser detection technique. The Degradation by channel fading can be reduced by diversity reception. This paper investigates a family of multiuser receivers that combined decor-relating detection, antenna diversity and RAKE multipath diversity. The performance of the multiuser receivers is analyzed. The results demonstrate a significant increase in the performance of the receivers by using multiuser detection and diversity reception.
基金Project supported by the National Natural Science Foundation of China （Grant No.60372107）
文摘Throughput of mobile ad hoc network （MANET） is limited by collision avoidance. In CDMA-based MANET, this limitation can be overcome by multiuser detection （MUD） because conventional colliding packets can be detached and detected by MUD so that multi-packet reception （MPR） is possible. This paper introduces the principles of MUD algorithm for MANET, and proposes an adaptive blind MUD algorithm. A special medium access control （MAC） protocol is designed to make MANET more efficient. This is achieved by sending more packets to a destination simultaneously. The proposed MUD algorithm and MAC protocol allow CDMA-based MANET to support MPR. Simulations show a remarkable improvement in the throughput performance of MANET.
基金the National Natural Science Foundation of China(No.60574016).
文摘In this paper, an uplink power control problem is considered for code division multiple access （CDMA） systems. A distributed algorithm is proposed based on linear quadratic optimal control theory. The proposed scheme minimizes the sum of the power and the error of signal-to-interference ratio （SIR）. A power controller is designed by constructing an optimization problem of a stochastic linear quadratic type in Krein space and solving a Kalman filter problem.
基金Supported by the National Natural Science Foundation of China (No.60472104)Doctoral innovative fund of Jiangsu province (xm04-32).
文摘Two blind multiuser detection algorithms for antenna array in Code Division Multiple Access (CDMA) system which apply the linearly constrained condition to the Least Squares Constant Modulus Algorithm (LSCMA) are proposed in this paper. One is the Linearly Constrained LSCMA (LC-LSCMA), the other is the Preprocessing LC-LSCMA (PLC-LSCMA). The two algorithms are compared with the conventional LSCMA. The results show that the two algorithms proposed in this paper are superior to the conventional LSCMA and the best one is PLC-LSCMA.
