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MIMO-CDMA base station space multiplexing transmitter system

A technology of MIMO-CDMA and transmitter, which is applied in the field of transmitter system algorithm of multi-user MIMO-CDMA base station, and can solve the problems of small interference, difficulty of hardware implementation and increased cost, difficulties, etc.

Inactive Publication Date: 2009-06-03
BEIJING JIAOTONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But it is still difficult, especially for mobile station (MS) systems to implement
The existing STS technology involves complex time exchange, which increases the complexity of the algorithm and the implementation cost of the CDMA system
[0003] Compared with STS, the existing MIMO system does not require space-time coding and decoding. The decoding of the mobile station receiver restores the data stream by multiplying the transposed channel matrix. For the mobile station, the matrix calculation will make its hardware implementation difficult and costly. greatly increase
In addition, only when the MIMO channels are highly independent, the existing MIMO system receiving algorithm can obtain decoded data with less co-channel interference
In common practical applications, MIMO channels are not highly independent, which will lead to co-channel interference and seriously affect the communication quality

Method used

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  • MIMO-CDMA base station space multiplexing transmitter system
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  • MIMO-CDMA base station space multiplexing transmitter system

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Experimental program
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Embodiment 1

[0037] Embodiment 1: Consider that in a CDMA system, the base station and the mobile station use MIMO technology to increase the system capacity and realize channel space multiplexing. Without loss of generality, in the MIMO-CDMA system of the present invention, both the base station and the mobile station use two antennas to transmit and receive data streams, and the distance between the two antennas of the base station and the mobile station is respectively 10 times the wavelength of the transmitted signal and 4 times The wavelength of the transmitting signal, the transmitting base station and the mobile station intend to communicate through two spatial channels, such as figure 1 shown.

[0038] Such as figure 2 As shown, the base station compares the two data streams sent to the kth mobile station and spread spectrum, get and

[0039] s 1 ( k ) = ...

Embodiment 2

[0063] Embodiment 2: The computer simulation result of MIMO CDMA system is given. It is assumed that the uplink of the MIMO CDMA system uses two antennas to transmit and receive from the MS to the BS, and it is assumed that the base station receiver obtains the best channel estimation.

[0064] In order to simplify the system simulation, let the number of mobile users be 64, and the spread spectrum c of each user in the MIMO CDMA system (k) The Walsh code with a code length of 64 is used, and the data of each user is modulated in BPSK mode. In order to verify that the MIMO-CDMA system is available, the existing MIMO CDMA system receiver algorithm and the MIMO CDMA system receiver algorithm proposed in this paper are selected. Both use the same spreading code and the number of users in the CDMA cell is the same.

[0065] In the system simulation, the system of the present invention and the base station of the existing system transmit 2000 data frames with a length of 64 under ...

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Abstract

The present invention relates to a MIMO-CDMA base station space multiplexing transmitter system. Different mobile station locates in different spatial position in a CDMA district, and different channel parameter matrix can be obtained. MIMO-CDMA base station transmitter uses different channel matrix between mobile station and base station for modulation so that each connected user can acquire two independent space channel, and each mobile station receiver divide received signal to two for dispreading directly without matrix operation, and get received data of this user after separate judgment to the dispread signal. The present invention provides a base station space multiplexing transmitter circuit applying the method. CDMA system frequency spectrum use ratio can be improved, and design of MIMO-CDMA base station transmitter can be simplified through the invention. MIMO-CDMA base station space multiplexing receiver system The present invention relates to a MIMO-CDMA base station space multiplexing receiver system. Different mobile station locates in different spatial position in a CDMA district, and different channel parameter matrix can be obtained. MIMO-CDMA base station transmitter uses different channel matrix between mobile station and base station for modulation, and then divide the modulation signal to two for dispreading, and get restored data of each mobile user after separate judgment to the dispread signal. The present invention provides a base station space multiplexing receiver circuit applying the method. Each connected user can obtain two independent space channel, CDMA system frequency spectrum use ratio can be improved, and design of MIMO-CDMA base station receiver can be simplified through the invention.

Description

technical field [0001] The invention mainly relates to a multiple-input multiple-output (MIMO) code division multiple access wireless communication system, especially a transmitter system algorithm of a multi-user MIMO-CDMA base station. Background technique [0002] So far, the bottleneck problem of multimedia wireless communication application is the problem of limited wireless spectrum bandwidth. In order to solve this problem, Smart Antenna (SA), Space Time Spread Spectrum (STS) technology and MIMO (Multiple Input Multiple Output) technology have been proposed successively to improve the utilization of wireless spectrum. Among these three technologies, although SA can fully utilize the spatial spectrum capacity, it is difficult for CDMA base station (BS) to implement SA because it is difficult to provide independent spatial beams for each mobile station. Therefore, the CDMA2000 standard and the WCDMA standard do not include SA in their standards, and only the TD-SCDMA s...

Claims

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Application Information

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IPC IPC(8): H04B7/06H04B7/08H04B1/707
Inventor 肖扬
Owner BEIJING JIAOTONG UNIV