WCDMA interference processing guide huawei

W-Interference Processing Guide-20060330-A-3.0 For internal use only Product name Confidentiality level WCDMA RNP For internal use only Product version Total 51 pages 3.0 W-Interference Processing Guide (For internal use only) Prepared by Li Junwei and Jiang Lihong Date Reviewed by Xie Zhibin, Li Wenhui, Hu Wensu, Qin Yan, Gong Haitao, Wan Liang, Yu Yongxian, and Hu Mingchao Date Qin Yan and Wang Chungui Date Reviewed by Approved by 2006-03-03 2006-03-16 2006-03-23 Date Huawei Technologies Co., Ltd All Rights Reserved 2006-06-29 Huawei Confidential No Spreading Without Permission Page of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only Revision Records Date Revised version Description Author 2006-03-03 3.00 Initial transmittal Li Junwei and Jiang Lihong 2006-03-15 3.01 Revising it according to the first review Li Junwei and Jiang Lihong 3.02 Modifying flow chats, adding acronyms and format, adding introductions to each chapter, modifying judgment criteria for internal and external interference, modifying cases, removing operators' information, adding figures to locating methods, and explaining the typical RTWP Li Junwei and Jiang Lihong 2006-03-22 2006-06-29 Huawei Confidential No Spreading Without Permission Page of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only Table of Contents Chapter Introduction to Interference Processing .9 Chapter Interference Processing Procedures 10 Chapter Methods for Finding Interferences 11 3.1 Finding Interferences by Network Operation Indexes 11 3.2 Sorting Candidate Cells by Priority 11 Chapter Interferences Analysis and Location 12 4.1 Collecting data and Confirming Interferences .12 4.1.1 Obtaining Interference Data 12 4.1.2 Confirming Interferences 12 4.1.3 Customizing Judgment Criteria for Abnormal Interferences 14 4.2 Judging Types of Interferences 14 4.2.1 Criteria for Judging Interferences .14 4.2.2 Sampling RTWP Variation Due to Internal Interference 15 4.2.3 Sampling RTWP Variation Due to External Interference 18 4.3 Equipment and Documents Needed In Interference Test 29 4.4 Locating Internal Interference 30 4.4.1 Initial Location 30 4.4.2 On-site Location 31 4.5 Locating External Interference 32 4.5.1 Preparations before On-site Location .32 Chapter Interference Elimination .35 Chapter Interference-related Cases 36 6.1 A Intermodulation Interference Case 36 6.2 Repeater Interference Case .36 6.3 Repeater Interference Case .36 6.4 Repeater Interference Case .36 6.5 Interference Location Cases in Indoor Distributed System 36 6.6 PHS-to-WCDMA Interference Location Cases 36 Chapter Introduction to Locating Downlink Interferences 37 7.1 Locating Downlink Interference 37 7.2 Analyzing Downlink Interference 37 7.3 Eliminating Downlink Interference .37 7.4 Downlink Interference Cases 37 Chapter Appendix 1: Basic Knowledge about Interference 38 8.1 Definition of Interference .38 8.2 Interference Influence 38 8.2.1 Influence on Sensitivity .38 8.2.2 Influence on Algorithm 38 8.2.3 Influence on System 38 8.3 The source and features of Interference .38 8.3.1 Internal Interference 38 8.3.2 External Interference .39 8.4 PIM Description 44 8.4.1 Connection of DIN connectors 45 8.4.2 Occurrence of Antenna PIM 45 8.4.3 Controlling Antenna PIM 45 8.4.4 Features of Antenna PIM 46 8.4.5 Relationship between PIM and NodeB Alarms .46 Chapter Appendix 2: RTWP Description 47 9.1 RTWP Definition 47 9.2 Uplink RF Channel Adjustment Principles 48 2006-06-29 Huawei Confidential No Spreading Without Permission Page of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only 9.3 RTWP Error and Accuracy 49 9.4 RTWP Effect 50 List of Reference .51 2006-06-29 Huawei Confidential No Spreading Without Permission Page of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only List of Tables Table 3-1 Sample list of network operation indexes 11 Table 4-1 Equipment and Documents 29 Table 8-1 Technical parameters of PHS system 39 Table 9-1 Received total wide band power(TS 25.215 v600) 47 Table 9-2 Absolute accuracy requirement .49 Table 9-3 Relative accuracy requirement 49 Table 9-4 Received total wideband power measurement report mapping 49 2006-06-29 Huawei Confidential No Spreading Without Permission Page of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only List of Figures Figure 2-1 Interference processing flow chat 10 Figure 4-1 Analyzing interference in Nastar 13 Figure 4-2 Configuring judgment criteria for abnormal interference in Nastar 14 Figure 4-3 Variation of RTWP due to load .16 Figure 4-4 Variation of RTWP due to improper connection of multiple RF 16 Figure 4-5 Antenna-feeder structure 17 Figure 4-6 Variation of RTWP 17 Figure 4-7 Variation of RTWP due to interaction of 2G and 3G signals 18 Figure 4-8 Site distribution around the site 501800 .19 Figure 4-9 Variation of RTWP in adjacent cells (1) 19 Figure 4-10 Variation of RTWP in adjacent cells (2) 20 Figure 4-11 Variation of RTWP in adjacent cells (3) 20 Figure 4-12 Variation of RTWP in adjacent cells (4) 20 Figure 4-13 Variation of RTWP in adjacent cells (5) 21 Figure 4-14 Variation of RTWP in adjacent cells (6) 21 Figure 4-15 Variation of RTWP 22 Figure 4-16 RTWP variation of cell 45680 .22 Figure 4-17 Antenna location 23 Figure 4-18 RTWP variation 23 Figure 4-19 Site location 24 Figure 4-20 RTWP variation of a NodeB near railway .24 Figure 4-21 RTWP variation due to indoor air-conditioner .24 Figure 4-22 RTWP variation due to power on or off of outdoor air-conditioner of other operator 25 Figure 4-23 RTWP variation due to power on or off of indoor emergency lights .25 Figure 4-24 Long-time RTWP variation 26 Figure 4-25 Short-time RTWP variation 26 Figure 4-26 Frequency spectrum when the directional antenna approaches the YBT250 27 Figure 4-27 Uplink interference due to transmission line (1) 27 Figure 4-28 Uplink interference due to transmission line (2) 27 Figure 4-29 Long-time RTWP variation of the interference like self-excitation 28 Figure 4-30 Short-time RTWP variation of the interference like self-excitation .28 Figure 4-31 Frequency spectrum feature .28 Figure 4-32 Structure of interference test 29 2006-06-29 Huawei Confidential No Spreading Without Permission Page of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only Figure 4-33 RTWP variation when the diversity reception is not configured 31 Figure 4-34 Locating interference source by using AOA 33 Figure 4-35 Schematic drawing of middle location 34 Figure 4-36 Schematic drawing of two-point location 34 Figure 8-1 Frame structure of PHS system .39 Figure 9-1 Structure of uplink Rx channel of V1.3 NodeB .47 2006-06-29 Huawei Confidential No Spreading Without Permission Page of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only W-Interference Processing Guide Key words: WCDMA, interference, main, diversity, RTWP, and intermodulation Abstract: this document discusses the processing methods and process Acronyms and abbreviations: Acronym and Abbreviations Full spelling PIM Passive Interactive modulation RTWP Received Total Wideband Power BCCH Broadcasting Channel FNE Fixed Network Element AOA Angle of Arrival 2006-06-29 Huawei Confidential No Spreading Without Permission Page of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only Chapter Introduction to Interference Processing This document aims to satisfy on-site engineers with the request from locating uplink interferences in WCDMA networks and provides common methods and operation process for locating uplink interference in WCDMA networks This document consists of the following chapters and content: 1) 2) 3) 4) 5) 6) 7) 8) 2006-06-29 Chapter Chapter Chapter Chapter Chapter Chapter Chapter Chapter Introduction to Interference Processing Interference Processing Procedures Methods for Finding Interferences Interferences Analysis and Location Interference Elimination Interference-related Cases Introduction to Locating Downlink Interferences Appendix Huawei Confidential No Spreading Without Permission Page of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only Chapter Interference Processing Procedures This chapter provides interference processing procedures, which are detailed in the following chapters Figure 2-1 Interference processing flow chat 2006-06-29 Huawei Confidential No Spreading Without Permission Page 10 of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only Chapter Introduction to Locating Downlink Interferences The downlink interference influence a small number of UEs and the areas affected by the interference is scattered A fixed interference source only influence a very small area and it is eliminated only in specific situations (subscribers' complaints and influencing KPIs) 7.1 Locating Downlink Interference When the RSCP is strong and Ec/Io is weak upon cell coverage analysis, not due to pilot pollution after confirmation, downlink interference is possible 7.2 Analyzing Downlink Interference When the downlink interference is located, the interfered areas are clear by using geographic display function of RNO tools Therefore, go to the interfered areas with YBT250 for confirmation For detailed usage of YBT250, see W-Apparatus Usage Guide 7.3 Eliminating Downlink Interference If eliminating the interference is difficult for equipment vendors, so it must be under the cooperation of equipment vendors and the operator 7.4 Downlink Interference Cases Indoor infrared equipment causes downlink interference 2006-06-29 Huawei Confidential No Spreading Without Permission Page 37 of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only Chapter Appendix 1: Basic Knowledge about Interference 8.1 Definition of Interference The signals that influence a communication system in the network are interference signals The unnecessary signals for the communication system are also interference signals In addition, the non-system internal signals which are present in RX inband but not influence system operations are also interference signals 8.2 Interference Influence 8.2.1 Influence on Sensitivity The continuous interference causes RTWP to increase by the same amount as the sensitivity decrease by The influence on sensitivity by the purse interference is related to duty ratio of pulse width interference Different pulse width and duty ratio have different influence on sensitivity The interference on sensitivity by pulse interference is unrelated to the influence on RTWP by RTWP Actually most interference has little impact on sensitivity 8.2.2 Influence on Algorithm The pulse interference influences the RTWP-related algorithm, such as admission control, congestion control, and load balance 8.2.3 Influence on System All interference influences the system in different aspects, such as sensitivity and algorithm 8.3 The source and features of Interference 8.3.1 Internal Interference The internal interference includes: z z 2006-06-29 Interference related to transmitted signals and intermodulation due to transmitted signal participation Interference related to transmission channels It seldom occurs that the transmitted signals interfere with RX band due to broken power amplifier However, when the power amplifier is broken, the transmitter becomes problematic Therefore the transmitted signals interfere with RX band The cause to the problem is multiple stage intermodulation Internal interference is usually unrelated to the reverse intermodulation of transmitter but related to passive devices The self-excitation in RX inband brings more interference The spectrum expansion: the power amplifier is abnormal, so the spectrum is expanded to RX Huawei Confidential No Spreading Without Permission Page 38 of 51 W-Interference Processing Guide-20060330-A-3.0 For internal use only inband The unlocked situation: the frequency drifts to RX inband The possibility of occurrence of problems on the transmitter is smaller than 1% Interference related to receiver channels, receiver self-excitation, intermodulation caused by transmitted signals within the receiver, unlocked situation, abnormal RTWP caused by unfixed frequency, and congestion caused by strong signals z 8.3.2 External Interference I Other Communication Systems The interference does not exist in normal situations It exists in those countries with improper allocation of spectrum You need to pay attention to the interference only when the frequency in band and band is used in the same area If a country for band uses the frequency in band 2, interference appears, which are destined to appear Therefore this interference must be known upon network construction with known influence 1) Interference to WCDMA system by PHS system Basic features of domestic PHS system According to the RCR STD-28 standard, the carrier bandwidth of PHS is 300 kHz, with a frame per 5ms A frame is divided to timeslots, with the timeslot structure shown in Figure 8-1 z Figure 8-1 Frame structure of PHS system Note: The uplink and downlink protection interval is 4.7us According to related rules and RCR STD-28 standard, the PHS frequency range is 1900.1–1915.0 MHz In some place, the frequency may reach 1918 MHz, which is beyond the range The PHS system uses continuous dynamic channel selection as an important advantage The base transceiver station (BTS) automatically measures the interference within the working frequency band and automatically select the channel with minimum inference for talk When the interference to the serving channel is so strong that continuous work is impossible, the BTS reselects new channel for talk or even enable the MS to handover to another BTS Therefore the continuous dynamic channel selection is of high utilization of spectrum The PHS BTS transmits signals that are selected one from four and receives four-path combined signals with maximum ratio z Technical parameters of PHS system Table 8-1 Technical parameters of PHS system BTS transmit power (peak) 2006-06-29 4000 mW (average: 500 mW) 80 mW (average: 10 mW) Antenna gain dBi dBi (body loss) Diversity gain Transmit: dBi; receive: dBi dBi Huawei Confidential No Spreading Without Permission Page 39 of 51 W-Interference Processing Guide-20060330-A-3.0 Needed C/I 10 dB Adjacent channel leakage power * Δf < 800 nW Scatted transmission 50 dB z 2006-06-29