CDMA VSWR Detection White Paper V1.0(20091015)

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CDMA VSWR Detection WhitePaper

Issue Issue 1.0

Date 2013-07-03

HUAWEI TECHNOLOGIES CO., LTD.


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CDMA SWR Detection White Paper

Copyright Huawei Technologies Co., Ltd. 2009. All rights reserved.

No part of this document may be reproduced or transmitted in any form or by any means without prior

written consent of Huawei Technologies Co., Ltd.

Trademarks and Permissions

and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd. All other trademarks

and trade names mentioned in this document are the property of their respective holders.

Notice

The purchased products, services and features are stipulated by the commercial contract made between

Huawei and the customer. All or partial products, services and features described in this document may

not be within the purchased scope or the usage scope. Unless otherwise agreed by the contract, allstatements, information, and recommendations in this document are provided AS IS without warranties,

guarantees or representations of any kind, either express or implied.

The information in this document is subject to change without notice. Every effort has been made in the

preparation of this document to ensure accuracy of the contents, but all statements, information, and

recommendations in this document do not constitute the warranty of any kind, express or implied.

Huawei Technologies Co., Ltd.

Address: Huawei Industrial Base

Bantian, Longgang

Shenzhen 518129

People's Republic of China

Website: http://www.huawei.com

Email: [email protected]

Issue 1.0 (2013-07-03) Huawei Proprietary and Confidential

Copyright Huawei Technologies Co., Ltd.

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http://www.huawei.com/mailto:[email protected]://www.huawei.com/mailto:[email protected]


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Contents

1 Executive Summary......................................................................4

2 Introduction.................................................................................5

3 Solution.......................................................................................6

3.1 VSWR Inquiry Process............................................................................................................................................7

3.2 User Interaction Interface.................................................................................................................................... ....7

4 Conclusion.................................................................................11



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1 Executive SummaryPreviously, when the BTS transmission is faulty and the quality of the network is affected,engineers are required to troubleshoot the VSWR problem at the site using a measurement

device.

Huawei provides a function of remotely obtaining a precise VSWR, which replaces the local

test of the SITEMASTER. This reduces the cost of the device, manpower, networkconstruction, and maintenance. Thus, operators' competitive edge is built.



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2 IntroductionVSWR or SWR is short for Voltage Standing Wave Ratio. Because of different media, part ofthe electromagnetic energy is reflected when the electromagnetic wave is transmitted from

medium A to medium B. Then, the moving standing wave forms in area A. The VSWR is theratio between the moving standing wave voltage peak value and the voltage bottom value.

The ratio is calculated through the module value of the reflection coefficient.

VSWR = (1 + reflection coefficient module)/(1 - reflection coefficient module)

From the perspective of the energy transmission, the ideal VSWR is 1:1, which is the

transmission state of the moving standing wave. In such a case, resistance compatibility existsin the transmission cable. The worst VSWR is infinite. The module of the reflection

coefficient is 1, which is the absolute standing wave state. In such a case, full reflection exists

and no energy is transmitted. Therefore, the higher the VSWR is, the larger the reflection

power is, and the lower the transmission efficiency is.

In radio communications, because of the resistance incompatibility between the antenna andthe feeder, or the antenna and the transceiver, the high frequency energy's reflection occurs.

Then the reflection part together with the forward part forms the standing wave. The ratio

between the voltage peak value and the voltage bottom value in adjacent voltages is called

VSWR. If the VSWR is excessively high, the transmission distance is shortened. In addition,when the energy is reflected to the power amplifier of the transceiver, the power amplifier

pipe is subject to damage. Then the operation of the communications system is affected.



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3 SolutionPreviously, when the BTS transmission is faulty and the quality of the network is affected,engineers are required to troubleshoot the VSWR problem at the site using a measurement

device (the SITEMASTER, locate the VSWR problem).

Huawei provides a function to remotely obtain a precise VSWR. This reduces the cost of the

device, manpower, network construction, and maintenance, which enhances the operators'market competitiveness. In addition, this enables the network management center to

accurately query the VSWR of a BTS. The precision of the VSWR within 1.4 is 0.2.

Therefore, this function replaces the local test of the SITEMASTER.



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3.1 VSWR Inquiry Process

3.2 User Interaction InterfaceThe M2000 client provides the function of VSWR precision threshold customization. Thefunction consists of two standardized grades: grade one is from 1.50 to 1.80 ( 1.50 and

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CDMA VSWR Detection White Paper V1.0(20091015)