Base station transmitting circuit for CDMA system sparetime spread spectrum method

Abstract

The invention relates to a base station transmitting circuit for a CDMA system sparetime spread spectrum method, which comprises two lower sampling modules, a time delay module, a plurality of spread spectrum devices and two adders, wherein the time delay module is connected with one lower sampling module; the plurality of the spread spectrum devices are connected with the lower sampling modules or the time delay module respectively; the two adders are connected with the spread spectrum devices; and the two lower sampling modules sample a data stream into two data streams, wherein one data stream is delayed by the time delay module and enters the spread spectrum device. The time delay module adjusts the time difference between the two data streams, so that the time difference is equal to atime difference of the two data streams when the space between two transmitting antennas is 10 to 15 times of the wavelength of a radio frequency signal. The space between the transmitting antennas can be not more than 10 to 15 times of the wavelength of a transmitting signal. The space between the transmitting antennas of the base station can be in the range from more than four times of the wavelength of the transmitting signal to less than 10 to 15 times of the wavelength of the transmitting signal, so the base station transmitting circuit is more suitable for engineering, in addition, thecircuit design is simple, and spread spectrum codes of an odd data stream and an even data stream are obtained by a spread spectrum code.

Description

[0001] This application is a divisional application of the invention patent application "CDMA system space-time spread spectrum method and corresponding mobile station receiving circuit". The original application date: March 12, 2004, application number: 200410008815.0, invention name: CDMA System space-time spread spectrum method. technical field [0002] The invention relates to a base station transmitting circuit of a space-time spread spectrum method in a CDMA system, and belongs to the field of mobile communication. Background technique [0003] The direct spread spectrum technology of multiple transmit antennas is used in the forward and reverse links of CDMA system, which can effectively improve the system performance. CDMA 1X uses direct spread spectrum transmit diversity technology, which has two methods: [0004] (1) One is Orthogonal Transmit Diversity OTD (Orthogonal Transmit Diversity) [0005] The method is that the CDMA base station first separates the data ...

AI Technical Summary

Problems solved by technology

[0010] In the existing space-time spread spectrum technology (STS), the distance between the transmitting antennas of the base station must be greater than 10-15 times the wavelength of the radio frequency signal to ensure that the signals reaching each unit of the antenna array are not correlated with each other, which causes difficulties in engineering implementation

Because due to objective conditions, the spacing of CDMA base station transmitting antennas may not meet the aforementioned requirements

The existing space-time spread spectrum technology with multiple transmitting antennas requires the mobile station to have multiple antennas, which brings great difficulties to the technical realization of the mobile station, increases the cost of the mobile station, and increases the size of the mobile station

The receiving despreading algorithm in the aforementioned literature requires a large number of matrix operations, so it is difficult to implement

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