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Closed-loop transmitting diversity method combined with closed-loop power control

A technology of transmit diversity and closed-loop power control, which is applied in space transmit diversity, power management, diversity/multi-antenna systems, etc., and can solve problems such as increased complexity and forward capacity loss

Inactive Publication Date: 2005-03-30
BEIJING UNIV OF POSTS & TELECOMM
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  • Abstract
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  • Application Information

AI Technical Summary

Problems solved by technology

Some transmit diversity systems, including open-loop and closed-loop diversity (such as STBC, OTD, STD, etc.), require the base station to transmit auxiliary pilots on the second antenna so that the mobile station can measure the channel conditions from the two antennas separately. In addition to adding a certain amount of complexity, it also means a loss of forward capacity

Method used

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  • Closed-loop transmitting diversity method combined with closed-loop power control
  • Closed-loop transmitting diversity method combined with closed-loop power control
  • Closed-loop transmitting diversity method combined with closed-loop power control

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Embodiment Construction

[0012] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0013] When adopting the method of the present invention, an embodiment of the system constitutes such as figure 1 As shown, the figure includes two major parts of the base station (11) and the mobile station (12).

[0014] In the base station, 12 and 13 are the first and second antennas respectively; 14 is an amplifier with controllable power; 15 is a power divider, which distributes the power of the transmitted signal to the two antennas equally; 16 is a step-by-step control The phase shifter, its phase shift range must reach 360°; circuit 17 is used to control 15 and 16; part 18 is a circuit for receiving feedback instructions for identifying mobile stations. Compared with the existing single-bit closed-loop power control system, the newly added parts of the present invention are 13, 15, and 16, and the modified part of the present invention is 17, ...

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Abstract

The invention provides capability of closed loop diversity for CDMA system of using single bit closed loop power control already. Controlling closed loop power and sending closed loop diversity can be realized at same time through redefining command of feedback, adding a pair of antennas, a phase shifter, power divider and relevant control circuit at base station under condition of not increasing additional feedback load at mobile station, and not increasing additional assistant pilot frequency at base station. Mobile station does not need to estimate channel conditions from two antennas respectively, does not need to know number of antenna at base station. When there is only one pair of antenna at base station, it still is a single bit closed loop power control system; when there is two pair of antenna at base station, it possesses function for sending closed loop diversity automatically.

Description

technical field [0001] The invention relates to wireless communication technology, in particular to a forward closed-loop transmission diversity and closed-loop transmission power control method in a CDMA system. Background technique [0002] The CDMA system is an interference-limited system. Reasonably allocating the base station's transmission power so that the base station transmits power for each user just reaches the required amount can achieve the purpose of saving base station transmission power and reducing interference, thereby effectively increasing the system capacity. Due to various reasons such as mobile station movement, shadows, fast fading, and interference changes, the system needs to use closed-loop transmission power control (hereinafter referred to as closed-loop power control) technology to achieve the above-mentioned purpose. A commonly used closed-loop power control method is that the mobile station periodically measures the...

Claims

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Application Information

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IPC IPC(8): H04L1/06H04B7/005H04B7/02H04B7/06H04B7/26H04W52/08
Inventor 杨鸿文郭文彬
Owner BEIJING UNIV OF POSTS & TELECOMM
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