Southeast University

The Research Institute of Telecommunication Transmission, Mii

The Mitt Research Institute of Telecommunication Transmission

Liangcheng Jiang

Xiaohu You

Shixin Cheng

Chunming Zhao

Jinghong Guo

Yan Zhang

Ling Wang

Junchao Wang

Zhangyong Ma

The present invention relates to a method and an apparatus for adjusting an average interval of channel estimation dynamically based on Doppler-shift. The method comprises the steps of estimating Doppler-shift by using level cross rate (LCR) according to differently moving speeds of mobile terminals, determining the optimal average interval of channel estimation based on the relationship between the existing Doppler-shift and the optimal average interval of channel estimation, dynamically adjusting the average interval of channel estimation according to the determined the optimal average interval of channel estimation to make the coherent receiver obtain the optimal estimation performance at different moving speeds. The apparatus of the present invention comprises a channel estimation module, a valid/strongest finger selection module, a RAKE demodulation and combining module, a RAKE output decision module, an LCR detection and Doppler-shift estimation module, a Gaussian noise power estimation module, a strongest path signal power estimation module, and an optimal average interval calculation module.

Method and equipment for regulating dynamically an average area of a channel estimation

The present invention discloses an apparatus for initial synchronization and cell search in a CDMA system based on multipath energy window. The apparatus perform initial synchronization and adjacent cell search by using multipath energy window based on the processing method of multipath energy window. The apparatus can be implemented based on a parallel correlator bank. This invention also provides the application of the apparatus to a coherent spreading receiver.

Means for initiative synchronization and cell searching based on the CDMA system of multipath energy window

The Spread Spectrum integration coherent receiver of the invention employs a time division multiplexing correlator bank and thus obtained coherent channel evaluator as a core. The receiver can execute initial PN synchronization, RAKE diversity coherent combination, AFC and adjacent cell search and combination receipt, and soft handoff. Further, 'part capture in parallel based on slide energy window' and 'tracking loop based on energy window barycenter' are introduced into the receiver of the invention, thereby simplifying the structure of the RAKE receiver. The receiver is capable of overcoming multipath fading, ensuring the RAKE receipt performance.

DS-CDMA integration spreading coherent receiver

An automatic frequency correction (AFC) apparatus used for CDMA multipath fading channels comprises a frequency-offset evaluator, an automatic frequency correction loop filter and a carrier frequency adjuster. The present invention provides a 'multipath energy window' designing method for the non-determinacy of multipath signals in mobile communication environment. Frequency-offset information can be extracted from the multipath energy window by a simple calculation and evaluated by a maximal SNR weight process. This invention also provides a step-variable accumulation adjusting method and greatly improves the response speed of the AFC apparatus as compared with a conventional loop filter, whereby supplies better AFC required for CDMA mobile terminals.

Frequency auto-correction apparatus for CDMA multipath fading channel

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Jiangsu, China

Liangcheng Jiang