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2003 Vol. 25, No. 4
Display Method:
Two linear intercarrier interference cancellation techniques in ofdm systems over multipath channels
2003, 25(4): 433-438.
Abstract:
InterCarrier Interference (ICI) is an important, factor degrading the performance of Orthogonal Frequency Division Multiplexing (OFDM) systems. Two linear ICI cancellation techniques, Frequency RAKE (F-RAKE) and frequency equalization (F-FIR), with d...
InterCarrier Interference (ICI) is an important, factor degrading the performance of Orthogonal Frequency Division Multiplexing (OFDM) systems. Two linear ICI cancellation techniques, Frequency RAKE (F-RAKE) and frequency equalization (F-FIR), with d...
2003, 25(4): 439-446.
Abstract:
As time-variant multipath channels, the time-variant property of MW and SW channels causes the interchannel interfere (ICI) between different subchannels of OFDM-based digital amplitude modulation broadcasting (DAMB) system. In this paper, the OFDM s...
As time-variant multipath channels, the time-variant property of MW and SW channels causes the interchannel interfere (ICI) between different subchannels of OFDM-based digital amplitude modulation broadcasting (DAMB) system. In this paper, the OFDM s...
2003, 25(4): 447-452.
Abstract:
In this paper, the status of transcoder buffer is analyzed. The conditions that have to be met by both the encoder and transcoder buffers for preventing the decoder buffer from underftowing or overflowing are derived also. A model of sequence image t...
In this paper, the status of transcoder buffer is analyzed. The conditions that have to be met by both the encoder and transcoder buffers for preventing the decoder buffer from underftowing or overflowing are derived also. A model of sequence image t...
2003, 25(4): 453-459.
Abstract:
In this paper, based on an embedding strategy for watermarking in DWT domain, the influence of characteristics of orthogonal wavelet for the robustness of watermarking and the selection of wavelet bases are mainly investigated. The results show the f...
In this paper, based on an embedding strategy for watermarking in DWT domain, the influence of characteristics of orthogonal wavelet for the robustness of watermarking and the selection of wavelet bases are mainly investigated. The results show the f...
2003, 25(4): 460-466.
Abstract:
A practical mathematic model of modulation characteristics of Propeller Aircraft (PA) returns in the Low-Resolution Radars (LRR) is proposed in the paper, based on configuration of PA and characteristics of LRR. The model is analyzed and simulated wi...
A practical mathematic model of modulation characteristics of Propeller Aircraft (PA) returns in the Low-Resolution Radars (LRR) is proposed in the paper, based on configuration of PA and characteristics of LRR. The model is analyzed and simulated wi...
2003, 25(4): 467-472.
Abstract:
Due to the multiplicative nature of the speckle noise in SAR images, for edge detecting of SAR images, few method can be found to detect edges efficiently while depress the speckle noise effects without too much false edges, especially in the low loo...
Due to the multiplicative nature of the speckle noise in SAR images, for edge detecting of SAR images, few method can be found to detect edges efficiently while depress the speckle noise effects without too much false edges, especially in the low loo...
2003, 25(4): 473-478.
Abstract:
This paper points out that a class of chaotic stream ciphers proposed recently is not secure enough, which is based on digital Piecewise Linear Chaotic Maps (PLCM). It has been known that digital PLCMs statistical properties have essential degradatio...
This paper points out that a class of chaotic stream ciphers proposed recently is not secure enough, which is based on digital Piecewise Linear Chaotic Maps (PLCM). It has been known that digital PLCMs statistical properties have essential degradatio...
2003, 25(4): 479-485.
Abstract:
This paper presents the expressions of three bounds and three ranges on handover performance in CDMA system, and divides the space of handover performance into several parts according to the six expressions. In order to form the basis of the above ex...
This paper presents the expressions of three bounds and three ranges on handover performance in CDMA system, and divides the space of handover performance into several parts according to the six expressions. In order to form the basis of the above ex...
2003, 25(4): 486-494.
Abstract:
A new analytical model for the TCP throughput, considering the packet losses caused by high and bursty errors in wireless links, is proposed. The analysis and numerical simulation prove that this model is exact and simple. And it is shown that channe...
A new analytical model for the TCP throughput, considering the packet losses caused by high and bursty errors in wireless links, is proposed. The analysis and numerical simulation prove that this model is exact and simple. And it is shown that channe...
2003, 25(4): 495-502.
Abstract:
This paper presents a sub-optimal data-selected scheme based on chip-matched filter for the multi-user receiver in multi-path CDMA channels, and studies the impact of this scheme on Multiple-Access Interference (MAI) and Inter-Symbol Interference (IS...
This paper presents a sub-optimal data-selected scheme based on chip-matched filter for the multi-user receiver in multi-path CDMA channels, and studies the impact of this scheme on Multiple-Access Interference (MAI) and Inter-Symbol Interference (IS...
2003, 25(4): 503-508.
Abstract:
A Dynamical Reserved Bandwidth Allocation scheme (DRBA) for handoff in multimedia mobile networks is presented to reduce the call dropping probability and improve the bandwidth utilization. The proposed scheme reserves bandwidth for real-time handoff...
A Dynamical Reserved Bandwidth Allocation scheme (DRBA) for handoff in multimedia mobile networks is presented to reduce the call dropping probability and improve the bandwidth utilization. The proposed scheme reserves bandwidth for real-time handoff...
2003, 25(4): 509-514.
Abstract:
In this paper, the characteristics of two link adaptive algorithms based on Carrier to Interference ratio (C/I) and Packet Error Rate (PER) are discussed. Furthermore, two hybrid algorithms of link adaptation are proposed on the analysis of the exist...
In this paper, the characteristics of two link adaptive algorithms based on Carrier to Interference ratio (C/I) and Packet Error Rate (PER) are discussed. Furthermore, two hybrid algorithms of link adaptation are proposed on the analysis of the exist...
2003, 25(4): 515-521.
Abstract:
In this paper, a distributed packet scheduling algorithm called DHIOS(Distributed Hierarchical Ingress and Output Scheduling) is presented and simulated for an input and output queuing switch whose switch fabric is a shared memory. The distributed pa...
In this paper, a distributed packet scheduling algorithm called DHIOS(Distributed Hierarchical Ingress and Output Scheduling) is presented and simulated for an input and output queuing switch whose switch fabric is a shared memory. The distributed pa...
2003, 25(4): 522-530.
Abstract:
Routing is an important topic in communication network research. But many existing routing mechanisms are awkward to highly dynamic network environment. With a proposed cooperative model of multi-agents based on fuzzy knowledge and a basic algorithm ...
Routing is an important topic in communication network research. But many existing routing mechanisms are awkward to highly dynamic network environment. With a proposed cooperative model of multi-agents based on fuzzy knowledge and a basic algorithm ...
2003, 25(4): 531-535.
Abstract:
It is one of advanced technologies used in modern radar that control nulls of the beam-pattern when array antenna radiates beams. This paper describes a phase-only conjugate gradient adaptive nulling method and the experimental radar adaptive nulling...
It is one of advanced technologies used in modern radar that control nulls of the beam-pattern when array antenna radiates beams. This paper describes a phase-only conjugate gradient adaptive nulling method and the experimental radar adaptive nulling...
2003, 25(4): 536-542.
Abstract:
In this paper a general study of the relation between the performance of shaped beams and beam width and spacing has been done for multiple-beam antennas with array-fed reflectors. Four parameters indicating the performance of shaped beams are first ...
In this paper a general study of the relation between the performance of shaped beams and beam width and spacing has been done for multiple-beam antennas with array-fed reflectors. Four parameters indicating the performance of shaped beams are first ...
A new kind of interconnect crosstalk model and estimation formula for high-speed integrated circuits
2003, 25(4): 543-550.
Abstract:
In this paper, an interconnect delay estimation model is built up, including the effect of distributed resistance, capacitance and even inductance. Then, on the basis of this model, the respondence of the terminal on the worst condition is analyzed a...
In this paper, an interconnect delay estimation model is built up, including the effect of distributed resistance, capacitance and even inductance. Then, on the basis of this model, the respondence of the terminal on the worst condition is analyzed a...
2003, 25(4): 551-556.
Abstract:
Broadband klystron is one of key devices in radar and communication system. The broadband performances of microwave output circuit play an important role for extending klystrons bandwidth. This paper describes the numerical results of a broadband out...
Broadband klystron is one of key devices in radar and communication system. The broadband performances of microwave output circuit play an important role for extending klystrons bandwidth. This paper describes the numerical results of a broadband out...
2003, 25(4): 557-561.
Abstract:
A new method of feature extraction for visual signal is presented in this paper. The signal of the image projection, which is acquired by CCD, is transformed with wavelet. And the zero cross point of transform is located at the center of the image wh...
A new method of feature extraction for visual signal is presented in this paper. The signal of the image projection, which is acquired by CCD, is transformed with wavelet. And the zero cross point of transform is located at the center of the image wh...
2003, 25(4): 562-566.
Abstract:
Multiuser detection in Code-Division Multiple Acess(CDMA) system is an effective method. The Partial Parallel Interference Cancellation(PPIC) detector is considered as an effective yet simple receiver. However, the optimal cancellation level which is...
Multiuser detection in Code-Division Multiple Acess(CDMA) system is an effective method. The Partial Parallel Interference Cancellation(PPIC) detector is considered as an effective yet simple receiver. However, the optimal cancellation level which is...
2003, 25(4): 567-572.
Abstract:
At first, in this paper, the feedback mechanisms of downlink channel quality for cdma2000 IxEV-DO/DV, a 3G technical proposal, are described briefly. Then a new feedback control algorithm is presented and integrated with proportional fair scheduling ...
At first, in this paper, the feedback mechanisms of downlink channel quality for cdma2000 IxEV-DO/DV, a 3G technical proposal, are described briefly. Then a new feedback control algorithm is presented and integrated with proportional fair scheduling ...
2003, 25(4): 573-576.
Abstract:
For most sequences at very low bit rates, the value of motion compensation data usually is very small, and will all be reduced into zero after DCT and quantization. Alice Yu method(1997) and Zhou method(1998) both are effective to predicting these Al...
For most sequences at very low bit rates, the value of motion compensation data usually is very small, and will all be reduced into zero after DCT and quantization. Alice Yu method(1997) and Zhou method(1998) both are effective to predicting these Al...
