Method for reducing co-channel interference in sector interval

Abstract

The invention discloses a method for decreasing the frequency interference of sectors, including: compositing the scrambling codes of the repeated codes which are likely to happen in the complex codes to form a number of base-scrambling code groups, and obtaining the corresponding relationships between the base-scrambling code groups and the downlink pilot-codes according to the splitting situation of the groups; distributing different base scrambling codes to the adjacent base stations; distributing a downlink pilot-code for each area which is different from the ones of the adjacent area according to the corresponding relationships between the base-scrambling code groups and the downlink pilot-codes; determining the scrambling code of this area based on the corresponding relationships between the distributed downlink pilot-codes and the base-scrambling code groups.

Description

technical field [0001] The invention relates to the technical field of mobile communication, in particular to a method for reducing co-frequency interference between sectors. Background technique [0002] An important means to improve system capacity and spectrum efficiency in a cellular mobile communication system is to adopt a sectorized cell structure. Sectorization of cells can not only improve the spectrum utilization rate of the system, but also reduce the demand for base station sites. Therefore, it has become one of the main economic networking methods. In the TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) system, although key technologies such as smart antennas and joint detection have been adopted to greatly increase the system capacity, supporting sectorized cells is still an indispensable improvement. means of system capacity. [0003] In the sectorized cellular mobile communication system, the non-ideality of the antenna radiation pattern w...

AI Technical Summary

Problems solved by technology

In this scenario, since both terminal A and terminal B are relatively close to the edge area between cell A and cell C, the shaped beams of their respective smart antennas are relatively wide. When terminal A and terminal B have the same working time slot, the Strong overlapping interference between beams is formed, and the joint detection technology generally used only for eliminating interference between users in a cell cannot eliminate such inter-cell interference

The existing scrambling code planning technology can't solve the problem. We have analyzed above. Due to the effect of scrambling codes, the actual spreading codes of users between cells in the TD-SCDMA system can no longer guarantee complete orthogonality. When the spreading codes of terminal A and terminal B have a certain correlation, the signals between the two terminals will form a certain degree of interference

Especially when terminal A is far away from base station A and terminal B is relatively close to base station A, in the downlink direction, since the base station needs to transmit stronger power to terminal A to overcome the influence of transmission path loss, at this time terminal B receives The signal transmitted by the base station to terminal A also has relatively strong power. At this time, the useful signal transmitted to terminal B may be submerged in the signal transmitted to terminal A, even if the correlation between the two user spreading codes is not very strong It will also bring a lot of interference and cause terminal B to fail to receive the signal correctly

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