Method for constructing TD-SCDMA multi-cell joint detection system matrix

Abstract

The invention provides a method for selecting a time division-synchronization code division multiple access (TD-SCDMA) channel estimation window, which comprises the following steps of: acquiring an observation time difference of each same frequency neighbor cell and a local cell; calculating Opos=mod(OTD, 16), wherein the OTD is the acquired observation time difference of the same frequency neighbor cell and the local cell; calculating a channel estimation value of an ith tap in the same frequency neighbor cell as hi in the formula, wherein wi is a channel estimation weighting coefficient, and the value of the wi is formula; comparing the magnitudes of the Pneg and Ppos; and if the Pneg is greater than the Ppos, selecting a valid channel estimation window corresponding to Oneg, otherwise, selecting a valid channel estimation window corresponding to Opos. The method adaptively selects the channel estimation window position of the same frequency neighbor cell by calculating the interference power when the channel estimation window of the same frequency neighbor cell falls in the channel estimation window of the local service cell, and constructs a system matrix in multi-cell joint detection so as to reduce the same frequency interference level of the system as much as possible and promote the performance of multi-cell joint detection.

Description

technical field [0001] The invention belongs to the technical field of mobile communication, in particular to a method for constructing a system matrix in multi-cell joint detection in a Time Division Synchronous Code-Division Multiple Access (TD-SCDMA) mobile communication system. Background technique [0002] The most critical in the third generation mobile communication system is Radio Transmission Technology (RTT). RTT candidate proposals collected by the International Telecommunication Union in 1998: In addition to 6 satellite interface technology solutions, there are 10 ground wireless interface technology solutions, which are divided into two categories: CDMA and TDMA, of which CDMA is dominant. In CDMA technology, the International Telecommunication Union currently accepts 3 standards, namely W-CDMA in Europe and Japan, CDMA2000 in the United States and TD-SCDMA in China. [0003] Compared with other third-generation mobile communication standards, TD-SCDMA adopts m...

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Problems solved by technology

The usual practice is to select the truncation position of the same-frequency adjacent cell according to the size and relative position of the time difference between the same-frequency adjacent cell and the local cell, that is, the channel impulse response falling in the window of the local cell will be used, and the channel impulse response falling in the local cell window will be used. The channel impulse response outside the cell window is set to zero. Usually, in order to limit the complexity of multi-cell joint detection, it is necessary to limit the window length of the channel impulse response of this cell, thereby limiting the length of the system matrix after correlation. Generally, it is simple to implement joint detection. , the length of the system matrix after correlation cannot exceed 32, and the code length is 16, that is, the channel impulse response window length of this cell cannot exceed 17, so this approach limits the scope of the system’s support for inter-cell OTD (such as figure 2 As shown, the 4th cell OTD exceeds 17, and the channel impulse response is completely set to zero), which limits the performance of multi-cell joint detection. In addition, this method is difficult to adapt to the distribution of various channel delay profiles, such as when the same When the channel delay profile of frequency adjacent cells is the minimum phase and maximum phase, it is difficult to obtain satisfactory performance for various delay profile distributions.

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