Title :
Iterative propagation delay estimation for asynchronous direct-sequence code division multiple access communication systems
Author :
Hong, Keun C. ; Ge, Hongya ; Wang, Kun
Author_Institution :
New Jersey Inst. of Technol., Newark, NJ, USA
Abstract :
We propose a centralized iterative time delay estimation scheme for asynchronous DS-CDMA communication systems. The proposed algorithm utilizes known training sequences and signatures for all multiple-access users to get the initial estimates of time delays. After that, the K-1 interfering signals are reconstructed with the estimated parameters and removed from the received data. A refined estimate of a desired user´s time delay is then obtained from the residual data. The estimation accuracy of the proposed algorithm is close to the centralized Cramer-Rao bound (CRB) after only one iteration
Keywords :
code division multiple access; delay estimation; iterative methods; maximum likelihood estimation; multipath channels; multiuser channels; radiofrequency interference; signal detection; signal reconstruction; spread spectrum communication; algorithm; asynchronous DS-CDMA communication systems; centralized Cramer-Rao bound; centralized iterative time delay estimation; decentralized linear filtering; decentralized maximum likelihood estimator; direct-sequence code division multiple access; estimated parameters; estimation accuracy; interfering signal reconstruction; iterative propagation delay estimation; multiple access interference; multiple-access users; multiuser detection; received data; residual data; signatures; time delay; training sequences; Delay effects; Delay estimation; Estimation error; Gaussian noise; Iterative algorithms; Multiaccess communication; Multiple access interference; Multiuser detection; Parameter estimation; Propagation delay;
Conference_Titel :
Spread Spectrum Techniques and Applications, 2000 IEEE Sixth International Symposium on
Conference_Location :
Parsippany, NJ
Print_ISBN :
0-7803-6560-7
DOI :
10.1109/ISSSTA.2000.878131
