Multi-path search method and device in CDMA system

Abstract

This invention discloses a multi-pass search method and a device, which utilizes the current phase of the output peak values and multi-path historical phase information being selected demodulation after searching peak values to delayed power spectrum of received signals to judge the match of phases and smoothly filters between the current power values of the peak values and historical power values of the being selected demodulation to demodulate the multi-path judgment and distribution by the updated being selected demodulated power value.

Description

Technical field [0001] The present invention relates to a multipath search method for a RAKE receiver in a CDMA communication system, in particular to a simple and efficient multipath search method for a RAKE receiver in the field of 3G mobile communication. Background technique [0002] Due to the good reception performance of CDMA spread spectrum communication technology in high-speed mobile multipath propagation environment, it has been widely used in wireless communication systems. At present, several mainstream 3G mobile communication systems in the world all use CDMA as their physical layer. The main transmission technology of the 3G mobile communication system, due to the high spread spectrum frequency generally adopted, by adopting the traditional RAKE receiver to obtain higher multipath resolution accuracy, thereby improving the multipath diversity receiving capability and achieving higher The receiving performance of the system and effectively improve the capacity of th...

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Problems solved by technology

[0006] 1. After despreading the input data, calculate the power delay spectrum, perform peak search on the power delay spectrum to obtain several peaks, and use the phase information of the peak value and the phase information of the current demodulated multipath to perform multipath synchronization / loss Step and other state judgments are used as the basis for effective multipath judgment. This method is relatively simple to implement and has a better performance improvement. However, due to the lack of full use of peak power information, the performance needs to be further improved.

[0007] 2. After despreading the input data, calculate the power delay spectrum, perform in-phase filtering on the power delay spectrum, perform peak search on the power delay spectrum after in-phase filtering, and then perform effective multipath judgment. This method makes full use of the in-phase filtering The peak power information is effectively reduced and the influence of interference and fading on performance is effectively reduced, and it has good performance, but due to the in-phase filtering, the amount of power delay spectrum buffering and calculation processing are large

[0008] In addition, there are some methods, such as the progressively refined multi-level search method and the joint multipath judgment method using the power information of the demodulation unit. These methods improve the performance to a certain extent, but are relatively complicated in design and implementation

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