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A novel Space Time Diversity Generalized Decorrelating Rake receive for multipath downlink DS-CDMA systems
, Article 2011 IEEE GCC Conference and Exhibition, GCC 2011, 19 February 2011 through 22 February 2011, Dubai ; 2011 , Pages 417-420 ; 9781612841199 (ISBN) ; Hosaini, S. N ; Khodadad, F. S ; Baghbanmanesh, M. R ; Sharif University of Technology
2011
Abstract
In this paper a novel Space Time Diversity Generalized Decorrelating Discrete Time Rake (STD-GD-DTR) for Upstream DS-CDMA system is proposed. The chosen algorithm for estimating the correct data is Maximum likelihood. In this method, a robust receiver based on maximum likelihood estimation is represented in which, space time diversity technique has been combined with generalized decorrelating discrete-time RAKE (GD-DTR) receiver to obtain higher performance than other widely used techniques for data estimation. Our proposed STD-GD-DTR ML based receiver provides high gains in the presence of channel estimation errors from similar methods. Simulation results illustrate the appropriate...
A practical approach for coherent signal surveillance and blind parameter assessment in asynchoronous DS-CDMA systems in multipath channel
, Article Proceedings - 2010 18th Iranian Conference on Electrical Engineering, ICEE 2010, 11 May 2010 through 13 May 2010 ; 2010 , Pages 305-310 ; 9781424467600 (ISBN) ; Ganji, F ; Aref, M. R ; Sharif University of Technology
Abstract
A novel, robust and practical method for active user enumeration in asynchronous CDMA in multipath channel condition is proposed in this paper. Most of the previous works do not consider the fact that in practical case, user's signals with the help of receiver arrive asynchronously. The proposed method can be used practically in blind multi-user detection such as eavesdropping; moreover, the method is based on information theory criteria which outperform other methods. Minimum description length (MDL) has better performance than all other information criteria used in such scenarios. Unlike most of the pervious works, we do not exploit array antenna to gather necessary data of the users....
Performance analysis of internally coded partial-band DS-CDMA system in multipath Rayleigh fading channel
, Article 2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, ICT-MICC 2007, Penang, 14 May 2007 through 17 May 2007 ; February , 2007 , Pages 29-34 ; 1424410940 (ISBN); 9781424410941 (ISBN) ; Nasiri Kenari, M ; Shayesteh, M. G ; Sharif University of Technology
2007
Abstract
We evaluate the performance of the internally coded partial-band DS-CDMA scheme first introduced in [1], in a multipath Rayleigh fading channel. The scheme of [1] is based on frequency-hopping (FH) and direct-sequence (DS) spread spectrum techniques. The total bandwidth is divided into Ns subbands. The output of a super-orthogonal encoder and a pseudorandom (PN) sequence selects one subband, in which the user's data is sent in the form of DS-CDMA signal using the second PN sequence. We consider soft detection at the receiver front end. We obtain the upper and lower bounds on the bit error rate. For comparison, we also consider the conventional DS-CDMA system. It is shown that for the same...