下载  >  开发技术  >  硬件开发  > LTE interference to DVB-C STB

LTE interference to DVB-C STB 评分

LTE interference to DVB-C STB
This report presents the results of an independent study undertaken by Cobham Technical Services to investigate potential interference from new mobile services in the 800 MHz band into Cable TV and broadband customer premises equipment The work was commissioned by ofcom in April 2010 and undertaken at Virgin Medias RF/Optical test facility in Birmingham over a seven week period the set Top Box (stB) and Cable Modem(CM equipment assessed in the study together with the test facility and associated technical support was kindly made available by virgin Media for the duration of the study. The scope of the technical research was discussed with both ofcom and virgin media and a detailed test plan was agreed prior to commencing the study. a radiated measurement programme was then undertaken to determine the potential for interference from Long Term Evolution (LTE User Equipment qUE) into 9 set top boxes and 12 cable modems for he following scenario A wanted signal level at the device under test of -8 dBmv(55 dBm), at the lower end of the operating range in the UK of-10 to +10 dBmV 64 QAM modulation for the sTBs and 256 QAM modulation for the Cmsi A simulated UE interferer with a 10 MHz bandwidth QPSK FDD reference channel based on full Resource Block(rB)allocation(50 RBs); A maximum Ue transmit eirp of 25 dbm based on a level of 23 dBm for UE Power Class 3+2 dB tolerance, as defined in section 6.2 of ETSI TS 136 521-1[1 Frequency offsets from co-channel(n) to N 9 channel separations for the stbs and±8 MHz for the cms; a separation distance of lm between the interferer and device under test The measurements were repeated to assess the performance from the front side and back of each stb, and from the front and side of each Cm. interference was taken to be the point of picture failure(pf)for the STBS or data failure for the Cms a sensitivity analysis was undertaken for a limited number of STBs to asses the impact of varying the wanted signal level and for various LTE UE partial resource block allocations Finally, five STBs and five CMs were examined with respect to their electromagnetic design to determine potential weaknesses in the designs and to recommend any improvements. It should be noted that all of the equipment tested was compliant with existing European requlations Ref: P: Projects Database\ofcom 2010-7A 05130 \Ofcom-7A0513009-CATV testing \ERA Reports\ Rep-6707-2010-0792 LTE into CATV. doc O ERA Technology Ltd Set Top Box Results The results show that 7 out of the 9 stbs tested could suffer interference from a ltE Ue handset operating at the maximum permissible transmit power of +25 dBm( 23 dBm EIRP 2 db tolerance)at 1m separation distance. Interference was only found to occur when the unwanted LtE signal was co-channel with the wanted CAtv signal; no adjacent, local oscillator, or image channel interference was observed Picture failure was generally found to occur at similar interference levels regardless of whether the interference source was radiating at lm from the front back or side of the STB under test. However, STB2 only suffered interference from the side while sTB4 and STB5 were marginally worse from the back, The performance of sTBl was much worse than the other stBs tested requiring around 21 dB more protection than the next worse case (STB9). It exhibited picture failure at a co-channel lte UE EIRP of around -3 dBm with a c/I protection ratio measured at the stb of -26 db. stb1 was the oldest box tested manufactured in 2003, and is considered to have the poorest design in terms of electromagnetic compatibility; STBs 9 6 and 2 were found to exhibit pf at a co-channel LtE UE eIRP of 15.76 dBm, 18.71 dBm and 21.06 d bm respectively with the interferer at 1m from the side STBs 9 and 6 are similar models which explains their similar performance: STBS 4, 5 and 8 were only found to exhibit pf at or near the maximum LTE UE EIRP(24-25 dBm). STBs 3 and 7 did not experience pf under any of the test conditions In all cases apart from sTbl, pf was only found to occur for frequency offsets of-5 to +5 MHz, when the 10 MHz LtE signal is essentially Co-channel and adjacent channel with the wanted signal. No image channel or STB local oscillator interference was found to occur. In all cases the Signal-to-Noise Modulation Error Ratio reported by the sTB diagnostics was degraded for frequency offsets from -8 to +8 MHz. Pre-Reed Solomon errors were typically found to occur at Snr of 28-24 db, post-Reed Solomon errors occur at 22 to 20 db and the stb loses lock completely when the SNR falls below 19 to 17 dB Cable modem results The results show that all 12 of the cms tested could suffer interference from a LtE UE handset operating at the maximum permissible transmit power of +25 dBm at 1m separation distance Ref: P: Projects Database(Ofcom 2010-7A 05130\Ofcom -7A0513009-CATV testing\ERA Reports\Rep-6707-2010-0792 LTE into CATV.doc 4 O ERA Technology Ltd The CMs under test were generally more prone to interference from the front. Only CM3, CM5 and CM11 exhibited worse performance from the side, with CM1l requiring an additional 11 dB of protection; CMs 12 and 9 were found to require the most protection they exhibited data failure at a co-channel ltE UE EirP of -13 dBm and -10 d bm respectively with the nterferer 1m from the front these two cms are similar models from the same manufacturer. CM12 is considered to have the poorest design in terms of electromagnetic compatibility CM1 was found to require the least protection, Data failure occurred at a co- channel lte ue eirp of +20 dbm performance was similar from both the front and side (within 1 dB. CMl is considered to have the best design in terms of electromagnetic compatibility; For CMs 2, 6,7,9, 11 and 12 data failure was found to occur for frequency offsets of -8 to +8 MHz (the maximum range tested Sensitivity Analysis The figure below shows that for every 1 dB increase in wanted signal level, the level of interference required to cause picture failure increases by approximately 1 dB. This suggests that operating the catv network at higher wanted signal levels could be a useful mitigation measure. The commercial, practical and technical feasibility of such a measure has not been examined Ref: P: Projects Database\ofcom 2010-7A 05130 \Ofcom-7A0513009-CATV testing \ERA Reports\ Rep-6707-2010-0792 LTE into CATV. doc 5 O ERA Technology Ltd The figure below shows the effect of reducing the number of LTE UE resource blocks on the EIRP required to cause picture failure. the results show that partial resource block allocations could cause higher levels of interference at the Stb. although the power density across the 10 MHz Lte bandwidth stays constant when the rb allocation is reduced, the peak power increases. Reducing the number of RBs from 50 to 1 increases the required protection ratio by around 3 dB. Electromagnetic Design Five set top boxes and five cable modems were reviewed with respect to their electromagnetic (EMC) design, to determine potential weaknesses in the designs and to recommend any design improvements All of the sTBs were found to have significant rectangular holes (apertures) in the metalwork that can allow unwanted frequencies to pass through which may then couple to sensitive circuitry. Overall the design of STBl is considered to be the poorest and this is reflected in the test results CM12 is considered from an inspection to have the poorest design based on the plastic case and the rF modulation/demodulation circuitry built on the PCB with no additional screening CMI was assessed to have the best design, with the rf circuit in a can and with the box having a conductive coating on the inside to provide a faraday cage. again these findings are reflected in the test results Ref: P: Projects Database\ofcom 2010-7A 05130 \Ofcom-7A0513009-CATV testing \ERA Reports\ Rep-6707-2010-0792 LTE into CATV. doc 6 O ERA Technology Ltd The Concise Report presented by the EtSI CENELEC joint working group at the European Commission Workshop in June 2010 [2] suggests that the radiated immunity of dvb tuners in the frequency range 790-862 MHz should be as a minimum 1 V/m in-band and outside this band 3 V/m. of the nine boxes tested only one failed the suggested limits. As noted above, this STB has poorer EMc design performance that the other STBs reviewed The results presented in this study for LtE UE interference into STBs at lm separation distance suggest that the design of these boxes should be adequate to meet the suggested limits. However seven out of the nine stbs tested could still suffer interference from a lte UE handset operating at the maximum permissible transmit power of +25 dBm at 1m (equivalent to 3 V/m co-channel) For CM's the results were worse, with only two out of twelve passing the suggested limits and all twelve suffering interference under the test conditions Virgin Media comment: These Draft ETSI immunity figures are based on what CPE Vendors who were part of the Digital Dividend Joint Working Group belleved were achievable in terms of the redesign of their eguipment. As 23 dBm equates to a transmission /eve/of 2,5 vIm at a separation distance of 1 metre, then an in-band immunity of I V/m is un/ikely to be enough to offer complete protection from a LTE UE in close proximity on-channel and transmitting at fullpower. The c7s testing does show that sTBs 9,6 and 2 were found to exhibit picture failure at a cO-channe/LTE UE EIRP of 15.76 dBm(1.1 Vm 18.71 dBm(1.5 vIm)and 21.06 dBm(2.0 Vm). They do indeed meet the new proposed fTSI standard, but still suffer picture failure at a separation distance of 1 metre with the wanted cable 7v signal towards the lower end of the input range Increasing the separation distance will increase the required UE power to cause a picture failure by 20logld, where d is the separation distance in metres. Ref: P: Projects Database\ofcom 2010-7A 05130 \Ofcom-7A0513009-CATV testing \ERA Reports\ Rep-6707-2010-0792 LTE into CATV. doc O ERA Technology Ltd Ref: P: Projects Database\ofcom 2010-7A 05130 \Ofcom-7A0513009-CATV testing \ERA Reports\ Rep-6707-2010-0792 LTE into CATV. doc 8 O ERA Technology Ltd Page No 2.1 Generic Test Set-Up 2.2 Unwanted LTE UE Parameters 18 2.3 Set-Top Box Parameters 2.3.1 Wanted signal parameters 20 23.2 Interference criterion 22 23.3 Test method 2.4 Cable modem parameters 24 2.4.1 Wanted signal parameters 2. 4.2 Interference criterion 27 2. 4. 3 Test method 2.5 Sensitivity analysis 8 2.5.1 Partial lte ue resource block allocations 28 3. 1 Set-Top Box Results 3.2 Cable modem results 37 3.3 Sensitivity Analysis 3.3.1 Wanted signal level 3.3.2 Partial resource block allocations 42 Ref: P: Projects Database\ofcom 2010-7A 05130 \Ofcom-7A0513009-CATV testing \ERA Reports\ Rep-6707-2010-0792 LTE into CATV. doc O ERA Technology Ltd 4. 1 Set Top Box design 45 4.2 Cable Modem Design 416 4.3 Implications of proposed radiated Immunity Test Levels Page No Table 1: Baseline test configuration 16 Table2: LTE UE Signal parameters,,,,…,…,…,,,…,,…,,……18 Table 3: SE42 boundary emission mask for FDD LTE UE uplink 19 Table 4: Wanted Set Top Box parameters. 21 Table 5: docsis downstream rF channel transmission characteristics ............................25 Table 6: DOCSIS upstream RF channel transmission characteristics. 26 Table 7: Wanted Cable Modem parameters.mmma..... ■■■■Ⅱ1ⅡBB11■面面11D■面口■D■_D 26 Table 8: Test variations 28 Table 9: Reference channels for 10 MHz QPSK with partial rb allocation.......ss. 29 Ref: P: Projects Database\ofcom 2010-7A 05130 \Ofcom-7A0513009-CATV testing \ERA Reports\ Rep-6707-2010-0792 LTE into CATV. doc 10 O ERA Technology Ltd

...展开详情
所需积分/C币:10 上传时间:2014-08-24 资源大小:1.06MB
举报 举报 收藏 收藏
分享 分享
LTE interference to DVB-C STB

LTE interference to DVB-C STB

立即下载
LTE from A to Z

著名培训机构的LTE培训教材。 深入浅出,从基本概念到深入描述。是一份比较全面的教材。全文367页。有料有内容。是一份难得的教材。 文件比较大,所以拆成3部分。这是part2 LTE from A-Z Technology and Concepts of the 4G 3GPP Standard Table of Content Principles and Motivation of LTE............................................1 1.1 Mobile Radio: Comparison between 3G and 4G.....

立即下载
LTE from A to Z (part1 of 3)

著名培训机构的LTE培训教材。 深入浅出,从基本概念到深入描述。是一份比较全面的教材。全文367页。有料有内容。是一份难得的教材。 文件比较大,所以拆成3部分。这是part1 LTE from A-Z Technology and Concepts of the 4G 3GPP Standard Table of Content Principles and Motivation of LTE............................................1 1.1 Mobile Radio: Comparison between 3G and 4G.....

立即下载
Heterogeneous Networks in LTE-Advanced

A comprehensive summary of theoretical and practical developments in LTE Heterogeneous Networks The last decade has witnessed the proliferation of mobile broadband data and the trend is likely to increase in the coming years. Current cellular networks are ill equipped to deal with this surge in d

立即下载
LTE for 4G Mobile Broadband

【原书作者】:Farooq Khan 【出版日期】:April 20, 2009 Do you need to get up to speed quickly on LTE? Understand the new technologies of the LTE standard and how they contribute to improvements in system performance with this practical and valuable guide, written by an expert on LTE who was intimately involved

立即下载
4G Femtocell Resource Allocation and Interference Management.

Femtocells have been considered as a promising technology to provide better indoor coverage and spatial reuse gains in the last few years. Femtocells are low power, low cost and user deployed wireless access points that use local broadband connections as backhaul. Not only the users but also the ope

立即下载
CoMP for the Uplink of LTE-advanced System

LTE-Advanced system based on orthogonal frequency division multiplexing (OFDM) can eliminate intra-cell interference since data are carried on the orthogonal subcarries; however, it can not mitigate inter-cell interference (ICI) which affects the performance severely. Therefore, coordinated mult

立即下载
Downlink MIMO in LTE-Advanced: SU-MIMO vs. MU-MIMO

Single-user multi-antenna technologies are well upported in current standard specifications like LTE Release 8/9. Further development of the specification (LTE-Advanced) is expected to conform to the requirements for IMT-Advanced systems. One of the key enabling features of LTE-Advanced to meet IMT-

立即下载
LTE from A-Z 培训教材 (part2 of 3)

著名培训机构的LTE培训教材。 深入浅出,从基本概念到深入描述。是一份比较全面的教材。全文367页。有料有内容。是一份难得的教材。 文件比较大,所以拆成3部分。这是part2 LTE from A-Z Technology and Concepts of the 4G 3GPP Standard Table of Content Principles and Motivation of LTE............................................1 1.1 Mobile Radio: Comparison between 3G and 4G.....

立即下载
Cloud and Fog Computing in 5G Mobile Networks-IET(2017).pdf

In order to continue to ensure the sustainability of mobile communication services over the next decade and to meet the business and consumer demands, fifth genera- tion (5G) mobile communication services is expected to be rolled out by 2020. One of the major requirements for 5G networks is the sign

立即下载
中移动c-ran白皮书 C-RAN The Road Towards Green RAN White Paper (v3.0)

Today‟s mobile operators are facing a strong competition environment. The cost to build, operate and upgrade the Radio Access Network (RAN) is becoming more and more expensive while the revenue is not growing at the same rate. The mobile internet traffic is surging, while the ARPU is flat or even de

立即下载
Multi-Carrier and Spread Spectrum Systems

The technological progress in multi-carrier (MC) modulation led orthogonal frequency division multiplexing (OFDM) to become an important part of beyond 3G cellular mobile communication standards, including LTE and WiMAX. In addition, the flexibility offered by the spread spectrum (SS) and time divis

立即下载
英文原版-Spectrum Sharing in Wireless Networks 1st Edition

Spectrum Sharing in Wireless Networks: Fairness, Efficiency, and Security provides a broad overview of wireless network spectrum sharing in seven distinct sections: The first section examines the big picture and basic principles, explaining the concepts of spectrum sharing, hardware/software functio

立即下载
ModbusTCP/RTU网关设计

基于UIP协议栈,实现MODBUS联网,可参考本文档资料,有MODBUS协议介绍

立即下载
html+css+js制作的一个动态的新年贺卡

该代码是http://blog.csdn.net/qq_29656961/article/details/78155792博客里面的代码,代码里面有要用到的图片资源和音乐资源。

立即下载
iCopy解码软件v1.0.1.7.exe

解ic,id,hid卡密码破解ic,id,hid卡密码破解ic,id,hid破解ic,id,hid卡破解ic,id,hid卡密码密码卡密码破解ic,id,hid卡...

立即下载
分布式服务框架原理与实践(高清完整版)

第1章应用架构演进1 1.1传统垂直应用架构2 1.1.1垂直应用架构介绍2 1.1.2垂直应用架构面临的挑战4 1.2RPC架构6 1.2.1RPC框架原理6 1.2.2最简单的RPC框架实现8 1.2.3业界主流RPC框架14 1.2.4RPC框架面临的挑战17 1.3SOA服务化架构18 1.3.1面向服务设计的原则18 1.3.2服务治理19 1.4微服务架构21 1.4.1什么是微服务21 1.4.2微服务架构对比SOA22 1.5总结23 第2章分布式服务框架入门25 2.1分布式服务框架诞生背景26 2.1.1应用从集中式走向分布式.26?

立即下载
Camtasia 9安装及破解方法绝对有效

附件中注册方法亲测有效,加以整理与大家共享。 由于附件大于60m传不上去,另附Camtasia 9百度云下载地址。免费自取 链接:http://pan.baidu.com/s/1kVABnhH 密码:xees

立即下载
电磁场与电磁波第四版谢处方 PDF

电磁场与电磁波第四版谢处方 (清晰版),做天线设计的可以作为参考。

立即下载
压缩包爆破解密工具(7z、rar、zip)

压缩包内包含三个工具,分别可以用来爆破解密7z压缩包、rar压缩包和zip压缩包。

立即下载