Zte Corporation

Zhaohua Zeng

Ping Li

Hongfeng Qin

Bin Li

Lei Li

Yuting Zhang

Peiyan Fei

Hai Bo Jiang

Wenfang Wang

Lujia Han

Jie Lei

Weiju Sun

Yong Zhan

Wenjuan Jia

Haihong Chen

A frequency offset estimation and correction method in an orthogonal frequency division multiplexing (OFDM) system is disclosed in present invention, including: obtaining a pilot frequency domain channel estimation value of a target user, and smoothing the channel estimation value in frequency domain; obtaining the link quality state of a receiver; adopting a history smoothing algorithm or a multi-branch attempt algorithm to perform frequency offset estimation and frequency offset compensation, performing frequency domain demodulation for the data for which frequency offset compensation has been performed, and outputting a link quality state parameter; and updating the link quality state of the receiver according to the link quality state parameter, determining the output value of this frequency offset estimation and outputting a history frequency offset value required by next frequency offset estimation according to the determined output value of this frequency offset estimation. A corresponding apparatus is also disclosed in the present invention.

Method and apparatus for frequency offset estimation and correction in orthogonal frequency division multiplexing system

The disclosure provides a downlink transmission method and an eNodeB in a multiple input multiple output system. The method includes: obtaining channel quality indication of a User Equipment (UE) to generate a channel condition indication value; obtaining channel rank indication of the UE to generate a channel correlation indication value; obtaining uplink channel impulse response estimation data of the UE to generate a channel variation state indication value; selecting a downlink transmission mode according to the channel condition indication value, the channel correlation indication value and the channel variation state indication value; transmitting data to the UE in the selected downlink transmission mode. Because of extracting information from a current channel as a basis of a subsequent selection of the downlink mode, the disclosure can greatly improve a resource utilization ratio of a system and realize a better wireless transmission effect.

Downlink transmission method and eNodeB in multiple input multiple output system

A baseband processing method based on double sampling, including: subjecting a received signal to root raised cosine-filtering process; sampling said signal; conducting channel estimation for every user based on the sampled data; and conducting multi-user joint detection and demodulation for said data. Wherein, the step of sampling said signal includes the following steps: conducting double sampling for said signal, and the interval of the sampling being &#xbd; chip; each chip selecting the average value of two sampling values as the sampling value of the chip; assembling the sampling value of every chip into a data stream. According to the present invention, in the case that the complexity of computation is not increased and only the memory space is doubled, the gain of the received signal in the system is improved effectively, especially when the synchronization of signals is bad, relatively large gain of the signals can be obtained, the system delay is reduced, and the real-time property of signal processing is improved. The method according to the present invention is suitable to the mobile communication system in a bad communication environment.

Baseband process method based on doubling sampling

Growing community of inventors

Shenzhen, China

Zhaohua Zeng