Uplink channel estimation for IMT-DS system
نویسندگان
چکیده
The IMT-DS system is one of the approved 3G radio interface standards which employ RAKE receivers to exploit multipath diversity. This paper discusses a new dimension in DS-CDMA channel estimation, i.e., chip-level adaptive channel estimation. A novel despreader-respreader based channel estimator (DRCE) is proposed to obtain uplink (UL) channel estimates at chip-level which resolves the deficiencies of conventional methods that work at symbol level. The DRCE employs an adaptive filter whose weights are adapted by using an LMS algorithm. The performance of the RAKE receiver with DRCE for an IMT-DS system is evaluated in terms of BER by simulations for pedestrian and vehicular channels
منابع مشابه
Adaptive Chip-Level Channel Estimation for IMT-DS System: DL and UL
In this paper, chip-level adaptive channel estimation has been explored by using LMS algorithm for wideband CDMA channel estimation. The expression for the optimum step-size is modified for fading channel estimation problem. In addition, a new method is proposed to obtain channel estimates with known pilot symbols which is found to give better results than other methods. For slow fading channel...
متن کاملDownlink channel estimation for IMT-DS
IMT-DS system is an approved terrestrial radio interface standard for 3G mobile communication based on direct sequence code division multiple access (DS-CDMA). It employs a RAKE receiver to exploit multipath diversity. This paper discusses a new dimension in DS-CDMA channel estimation i.e., chip-level adaptive channel estimation. The DL channel of an IMT-DS system consists of time-multiplexed p...
متن کاملFrequency-domain Differential Detection and Equalization for 2-dimensional spread/chip-interleaved DS-CDMA
Abstract The multiple-access interference (MAI) limits the performance of the DS-CDMA uplink transmission. 2D OVSF spread/chip-interleaved DS-CDMA is an MAI-free system, and hence single-user coherent frequency-domain equalization (FDE) can be used instead of complicated multiuser detection (MUD). However, coherent FDE needs channel estimation. Pilot-assisted channel estimation is not reliable ...
متن کاملCoherent Detection for DS/CDMA System with M -Ary Orthogonal Modulation in Multipath Fading Channels
In this letter, we propose the channel estimation technique in the uplink of a DS/CDMA system with M -ary orthogonal signaling over multipath fading channels. The channel estimation is carried out using the maximum correlator output of RAKE receiver. With the estimated channel parameters, the RAKE receiver can coherently combines the received multipath signals, resulting in a significant perfor...
متن کاملBlind Adaptive Space-Time Receiving and Transmitting Diversities For Multiuser DS-CDMA Systems
Blind adaptive space-time processing techniques are developed for both uplink reception and downlink transmission in multiuser TDD DS-CDMA systems to overcome multipath fading effect and multiple access interference. The system consists of a spacetime array, a decorrelator, and a weight-adapter. For uplink reception, a hybrid combination of constant modulus algorithm and decisiondirected algori...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2001