Clipping method and apparatus for TD-SCDMA system containing multiple frequency points

Abstract

The invention discloses a clipping method used for a time division-synchronous code division multiple access (TD-SCDMA) system with multiple frequency points. The method comprises the following steps: generating a phase rotation table with N*K phases, wherein N is the number of the multiple frequency points and the K is the number of subscriber at each frequency point; acquiring the transmitted data of the individual subscribers at the multiple frequency points; and randomly selecting a phase in correspondence with the transmitted data of each subscriber from the phase rotation table, changing the initial phase of the transmitted data of the subscriber by utilizing the selected phase to obtain the rotated transmitted data of the subscriber, merging the rotated transmitted data of the individual subscriber, and transmitting the merged data. The invention also discloses a clipping device used for a TD-SCDMA system with multiple frequency points.

Description

technical field [0001] The present invention relates to signal processing of a communication system, in particular to a phase rotation-based clipping method and device for clipping in a Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) system Methods and Apparatus. Background technique [0002] In the signal processing process of the communication system, in order to ensure signal transmission without distortion, a certain dynamic range needs to be reserved. Dynamic range can be defined by peak-to-average ratio. For the case of multi-carrier, since the average transmit power needs to be increased, the dynamic range of the signal is compressed; compared with single-carrier, the peak-to-average ratio requirement of multi-carrier is not only not reduced, but also higher. In order to meet the compromise between the average transmit power and the maximum transmit power, it is necessary to cut off the peak value (referred to as clipping) of the signal waveform t...

AI Technical Summary

Problems solved by technology

The above clipping method does not consider the N-frequency multi-carrier characteristics of the TD-SCDMA system, and there are problems such as complex calculations or difficulty in taking into account the clipping index.

[0008] In addition, for a multi-carrier system with N frequency points, each frequency point needs to be independently modulated and then combined, which will make the PAR very large

The signal with high PAR has higher requirements on the linear range of the amplifier. In order to reduce the linear range of the amplifier, the signal will be clipped. Requirements, and the greater the peak of the signal clipped, the worse the EVM (error vector value) and ACLR (adjacent channel leakage ratio) will be, the more serious the signal distortion will be, and the worse the clipping effect will be.

The above method obviously cannot solve the above problem

Images