Author: Stefano Buzzi (ingegnere.)Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Interference Suppression in DS/CDMA Systems Over Frequency-selective Fading Channels
Author: Stefano Buzzi (ingegnere.)Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Interference Suppression for DS-CDMA with Space and Time Diversity
Author: Wayne G. PhoelPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Finally, we consider transmitter diversity for the forward link of a DS-CDMA system. Orthogonal designs, which avoid self-interference from the multiple transmitters, are compared with space-time coding, which enables a lower code rate but introduces self-interference. The receiver uses a linear MMSE filter followed by a parallel Decision-Feedback Detector to cancel self-interference. In frequency-selective fading, space-time coding can provide a significant gain over orthogonal designs.
Blind Signal Detection for DS-CDMA Over Frequency-selective Fading Channels
Author: Weiguo LiangPublisher:
ISBN:
Category : Code division multiple access
Languages : en
Pages : 286
Book Description
The Performance of Matched-filter and MMSE Receivers for DS-CDMA Systems in Multipath Fading Channels
Author: Jeffrey Ronald FoersterPublisher:
ISBN:
Category :
Languages : en
Pages : 330
Book Description
Coding and Interference Suppression for CDMA Systems on Fading Channels
Author: Kai TangSusessive Interference Cancllers for Multimedia Multicode DS-CDMA Systems Over Frequency-selective Fading Channels
Author: 吳燦明Estimation of Fading Channel in DS-Cdma Multiuser Communications Systems
Author: Chun-Yu FungPublisher: Open Dissertation Press
ISBN: 9781374709430
Category :
Languages : en
Pages :
Book Description
This dissertation, "Estimation of Fading Channel in DS-CDMA Multiuser Communications Systems" by Chun-yu, Fung, 馮震宇, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of the Thesis Entitled Estimation of Fading Channel in DS-CDMA Multiuser Communications Systems submitted by Fung Chun Yu for the degree of Master of Philosophy at the University of Hong Kong in December 2002 Multipath fading and multiuser access interference are two major impairments in direct-sequence code-division multiple-access (DS-CDMA) systems. Efficient channel estimation and multiuser detection techniques play important roles in overcoming these deficiencies. This thesis is concerned with the design of a space-time (ST) blind adaptive receiver for DS-CDMA systems and the accompanied channel estimation algorithm. A new space-time decorrelating RAKE (ST-DRAKE) receiver is developed for blind reception of CDMA signals in frequency-selective fading channels. It has the advantage that only the knowledge of the desired user's signature waveform is required and therefore no transmission of training sequence is needed. The ST-DRAKE receiver consists of two parts. The first part is a set of constrained adaptive filters that are designed to suppress interference based on the minimum output energy criterion. These filters are implemented in a structure analogous to the general sidelobe canceller in array processing, which is implemented by a multistage Weiner filter is employed to reduce the complexity of the receiver. The second part of the ST-DRAKE receiver coherently combines the outputs of the constrained adaptive filters and gives an estimate of the transmitted signal. Simulation results show that the ST- DRAKE delivers significant performance improvement by exploiting the spatial diversity of the antenna array. The problem of estimating fast fading channels in the proposed receiver is also addressed. The time-varying channel is modeled as an autoregressive process and the Kalman filter is employed to estimate the time-varying channel coefficients. A robust Kalman filter based on the M-estimate cost function is also developed to suppress impulsive noise present in the received signals. Simulation results show that the Kalman filter provides more accurate channel estimate to the ST-DRAKE than using the decomposition method. Simulation results also show that the coupled receiver has a performance comparable to the optimum minimum mean-squared error receiver with known channel information. DOI: 10.5353/th_b2750902 Subjects: Code division multiple access Wireless communication systems
Interference Suppression Techniques for Multicarrier DS-CDMA.
Author: Weiping XuLinear Interference Suppression and Pulse Optimization for DS-CDMA.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
This project is concerned with the applicability of adaptive linear interference suppression for DS-CDMA in a peer-to-peer network. This technique is robust with respect to extreme near-far power variations. The following topics have been studied: (1) performance in the presence of time- and frequency-selective fading, (2) reduced-rank methods for faster convergence and tracking, (3) adaptive transmitter preprocessing for interference avoidance, (4) combined coding and interference suppression, and (5) performance in the presence of mixed rate traffic. Overall, our results indicate that adaptive linear interference suppression can be made robust with respect to time-varying channels and interference. Algorithmic enhancements which improve upon the performance in a dynamically changing environment have been proposed and evaluated.
Interference Suppression for DS/CDMA Systems in Non-Gaussian Impulsive Channels
Author: Seoyoung LeePublisher:
ISBN:
Category :
Languages : en
Pages : 238
Book Description
Simulation results show that the proposed detector provides remarkable performance improvements over the adaptive MD detector in a wide range of near-far situations. The proposed detector has much better near-far resistance than the adaptive MD detector. Finally, fuzzy hybrid detector combines the adaptive MD detector and the hard-limiting matched filter (HLMF) detector. The HLMF detector performs well when the additive impulsive noise significantly dominates over MAI. Simulation results indicate significant performance improvements over the adaptive MD detector alone in impulsive noise-limited environments. When MAI dominates, the fuzzy hybrid detector nearly has the same performance as the adaptive MD detector.