Scrambling discriminating method for time-division-synchronous code division multiple access system and code word partitioning method

Abstract

The present invention relates to a method for distinguishing scrambling codes and a method for dividing codewords in a time division-synchronous code division multiple access system. The method includes: firstly, each scrambling code and orthogonal variable length The spreading codes are compounded separately to generate a compound code, and the correlation calculation is performed on the compound code of each scrambling code and the compound code of another scrambling code; then, according to the correlation calculation results, the scrambling codes meeting the grouping conditions are divided into different In the scrambling code group; according to the scrambling code grouping, the code words of the time division-synchronous code division multiple access system are regrouped, so that the network planning using the grouping result can avoid the interference problem caused by the correlation, and also The selection range of the scrambling code can not be changed, so that a good network planning result can be obtained. By using the method provided by the invention, the search speed of the scrambling code can be increased, the time for searching the scrambling code can be saved, and the network capacity can be improved.

Description

technical field [0001] The invention relates to a method for grouping code words in a code division multiple access (CDMA) mobile communication system, in particular to a method for distinguishing scrambling codes and a method for dividing code words in a time division-synchronous code division multiple access (TD-SCDMA) system. Background technique [0002] The third-generation mobile communication system widely adopts the multiple access method based on CDMA, and its basic feature is to distinguish different users with different code words. In order to realize the cellular network structure, different CDMA systems have defined different code word usage and distribution schemes, so as to distinguish different users in the cellular network structure. [0003] Among them, the codes used in the TD-SCDMA system can be classified according to types: downlink pilot codes, uplink pilot codes, cell scrambling codes, and training sequence (midamble) codes. Refer to Table 1 for the ...

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Problems solved by technology

[0011] Although the planning method in the prior art can ensure that the DwPTS between adjacent cells is different, the planning result using this planning method does not take into account the correlation between the composite code word formed by the selected scrambling code and the spreading code. The strong mutual interference that may be brought about by nature may cause strong interference between the working code channels of two adjacent cells, so that the network configuration cannot be optimal; After selecting two different DwPTS and two different code groups for cell A and cell B respectively, in step 2, select scrambling codes for cell A and cell B respectively from the code groups. There may be strong mutual interference between the composite codes, resulting in strong interference between the working code channels of adjacent cells

The reason for this kind of interference is that in the process of network planning, the correlation problem between the composite codes composed of scrambling codes and spreading codes was not considered, and the 128 scrambling codes were not distinguished, resulting in The composite codewords used have strong correlation, and the occurrence of interference due to correlation cannot be avoided

[0012] In the prior art, in order to solve the above interference problem caused by the correlation between the composite codes, the correlation problem between the composite codes can be considered in the above step 2, so as to avoid the generation of interference. However, due to The scrambling code group has been determined in step 1. Therefore, the selection of the scrambling code considering the correlation problem can only be carried out within the range of the selected scrambling code group, thus limiting the possible Better scrambling code selection, so that the network configuration cannot be optimal;

[0013] If in the process of network planning, on the basis of uncertain scrambling code groups, directly consider the correlation problem and select the appropriate scrambling code, the number of scrambling codes is 128, which is much higher than the number of scrambling code groups 32 , therefore, directly selecting scrambling codes from 128 scrambling codes will greatly prolong the network planning search process, which is not suitable for network planning engineering site applications

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