LTE-RRU与射频原理介绍

1、LTE RRU与射频原理介绍LTE 协议主要内容RRU基本原理射频基本原理目录LTE RRU相关协议TS36.101Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio transmission and reception TS36.104Evolved Universal Terrestrial Radio Access (E-UTRA); Base Station (BS) radio transmission and reception TS36.141Evolved Universa

2、l Terrestrial Radio Access (E-UTRA); Base Station (BS) conformance testing TR36.801Evolved Universal Terrestrial Radio Access (E-UTRA); Measurement Requirements TR36.804Evolved Universal Terrestrial Radio Access (E-UTRA); Base Station (BS) radio transmission and reception TR36.942Evolved Universal T

3、errestrial Radio Access (E-UTRA); Radio Frequency (RF) system scenarios LTE RRU开发协议版本当前研发中以3GPP RAN39次全会后的版本为准相应的版本号是V8.1.0 LTE的信号带宽和传输带宽配置的关系Channel bandwidth BWChannel MHz1.43 5101520Transmission bandwidth configuration NRB615 255075100Chip rate（MHz）1.923.847.6815.3623.0430.72V8.1.0版本，去掉了1.6MHz和3.

4、2MHz带宽两种定义V8.1.0版本，去掉了对FDD和TDD的区分信道带宽和传输带宽配置定义LTE频段要求下行主要指标基站输出功率总功率动态范围频率误差EVM占用带宽ACLROperating band unwanted emissions（与WCDMA的辐射模板类似）杂散发射互调ACLR指标要求（FDD）E-UTRA transmitted signal channel bandwidth BWChannel MHz BS adjacent channel centre frequency offset below the first or above the last carrier ce

5、ntre frequency usedAssumed adjacent channel carrier (informative)Filter on the adjacent channel frequency and corresponding filter bandwidthACLR limit1.4, 3.0, 5, 10, 15, 20BWChannelE-UTRA of same BWSquare (BWConfig)45 dB2 x BWChannelE-UTRA of same BWSquare (BWConfig)45 dBBWChannel /2 + 2.5 MHz3.84

6、Mcps UTRARRC (3.84 Mcps)45 dBBWChannel /2 + 7.5 MHz3.84 Mcps UTRARRC (3.84 Mcps)45 dBNOTE 1:BWChannel and BWConfig are the channel bandwidth and transmission bandwidth configuration of the E-UTRA transmitted signal on the assigned channel frequency.NOTE 2:The RRC filter shall be equivalent to the tr

7、ansmit pulse shape filter defined in TS 25.104 6, with a chip rate as defined in this table.ACLR指标要求（TDD）E-UTRA transmitted signal channel bandwidth BWChannel MHz BS adjacent channel centre frequency offset below the first or above the last carrier centre frequency usedAssumed adjacent channel carri

8、er (informative)Filter on the adjacent channel frequency and corresponding filter bandwidthACLR limit1.4, 3BWChannelE-UTRA of same BWSquare (BWConfig)45 dB2 x BWChannelE-UTRA of same BWSquare (BWConfig)45 dBBWChannel /2 + 0.8 MHz1.28 Mcps UTRARRC (1.28 Mcps)45 dBBWChannel /2 + 2.4 MHz1.28 Mcps UTRAR

9、RC (1.28 Mcps)45 dB5, 10, 15, 20BWChannelE-UTRA of same BWSquare (BWConfig)45 dB2 x BWChannelE-UTRA of same BWSquare (BWConfig)45 dBBWChannel /2 + 0.8 MHz1.28 Mcps UTRARRC (1.28 Mcps)45 dBBWChannel /2 + 2.4 MHz1.28 Mcps UTRARRC (1.28 Mcps)45 dBBWChannel /2 + 2.5 MHz3.84 Mcps UTRARRC (3.84 Mcps)45 dB

10、BWChannel /2 + 7.5 MHz3.84 Mcps UTRARRC (3.84 Mcps)45 dBBWChannel /2 + 5 MHz7.68 Mcps UTRARRC (7.68 Mcps)45 dBBWChannel /2 + 15 MHz7.68 Mcps UTRARRC (7.68 Mcps)45 dBNOTE 1:BWChannel and BWConfig are the channel bandwidth and transmission bandwidth configuration of the E-UTRA transmitted signal on th

11、e assigned channel frequency.NOTE 2:The RRC filter shall be equivalent to the transmit pulse shape filter defined in TS 25.105 7, with a chip rate as defined in this table.Operating band unwanted emission指标举例（FDD与TDD相同）Frequency offset of measurement filter 3dB point, fFrequency offset of measuremen

12、t filter centre frequency, f_offsetMinimum requirementMeasurement bandwidth (Note 1)0 MHz f 5 MHz0.05 MHz f_offset 5.05 MHz100 kHz 5 MHz f 10 MHz5.05 MHz f_offset 10.05 MHz-14 dBm100 kHz 10 MHz f fmax10.5 MHz f_offset 1GHz) for Category BOperating band unwanted emission requirements levels relative

13、to channel edge (EUTRA bands 1GHz，Category B) 上行主要指标灵敏度动态范围信道内选择性（In-channel selectivity ）邻道选择性阻塞接收杂散接收互调 灵敏度指标要求（FDD与TDD相同）The throughput shall be 95% of the maximum throughput of the reference measurement channel as specified in Annex A with parameters specified in Table ：E-UTRAchannel bandwidth M

14、HzReference measurement channel Reference sensitivity power level, PREFSENS dBm1.4FRC A1-1 in Annex A.1-107.33FRC A1-2 in Annex A.1-103.65FRC A1-3 in Annex A.1-101.610FRC A1-3 in Annex A.1*-101.615FRC A1-3 in Annex A.1*-101.620FRC A1-3 in Annex A.1*-101.6 Note*: PREFSENS is the power level of a sing

15、le instance of the reference measurement channel. This requirement shall be met for each consecutive application of a single instance of FRC A1-3 mapped to disjoint frequency ranges with a width of 25 resource blocks each动态范围指标要求（FDD与TDD相同）E-UTRAchannel bandwidth MHzReference measurement channelWant

16、ed signal mean power dBmInterfering signal mean power dBm /channel BWType of interfering signal1.4FRC A2-1 in Annex A.2-76.8-88.7AWGN3FRC A2-2 in Annex A.2-72.9-84.7AWGN5FRC A2-3 in Annex A.2-70.8-82.5AWGN10FRC A2-3 in Annex A.2*-70.8-79.5AWGN15FRC A2-3 in Annex A.2*-70.8-77.7AWGN20FRC A2-3 in Annex

17、 A.2*-70.8 -76.4AWGNNote*: The wanted signal mean power is the power level of a single instance of the reference measurement channel. This requirement shall be met for each consecutive application of a single instance of FRC A2-3 mapped to disjoint frequency ranges with a width of 25 resource blocks

18、 each邻道指标要求（FDD与TDD相同）E-UTRAchannel bandwidth MHzWanted signal mean power dBmInterfering signal mean power dBm Interfering signal centre frequency offset from the channel edge of the wanted signal MHzType of interfering signal1.4PREFSENS + 11dB*-520.71.4MHz E-UTRA signal3PREFSENS + 8dB*-521.53MHz E-

19、UTRA signal5PREFSENS + 6dB*-522.55MHz E-UTRA signal10PREFSENS + 6dB*-522.55MHz E-UTRA signal15PREFSENS + 6dB*-522.55MHz E-UTRA signal20PREFSENS + 6dB*-522.55MHz E-UTRA signalNote*: PREFSENS depends on the channel bandwidth as specified in Table7.2-1.LTE 协议主要内容RRU基本原理射频基本原理目录FDD RRU基本原理框图TDD RRU基本原理框

20、图FDD RRU结构图LDDLF1PA20F1 电源模块TR1单板电源接口天馈接口AISG接口调试接口PIB单板并柜接口（LTE RRU已经取消）光口FDD RRU内部硬件关系图TDD RRU结构图TDD RRU内部硬件关系图RRU关键技术一：部件的重用性FDD RRU借用R8106的结构件和电源，收发信板里面的技术部分借用WCDMA相关技术TDD RRU借用Wimax RRU的硬件系统RRU关键技术二：高效率功放技术功放是整个RRU系统里面热耗最大的部分，要实现RRU的高效率，就必须实现功放的高效率。目前的几种高效率功放技术大概有以下几种：Class ABDohertyAdvanced Do

21、herty：Multi-stage DohertyUnbalanced DohertyETRRU关键技术三：CFR & DPD技术CFR是用来降低信号峰均比的技术DPD技术是目前较为成熟的一项改善功放线形性的技术通过CFR与DPD的结合，可以降低峰均比，改善功放线形，从而在保证输出性能要求的前提下，减少功放的回退，达到提高功放效率的目的。为了降低信号峰均比，需要对峰值信号进行抵消，从而加大信号的噪声功率。由于LTE对EVM的要求高于WCDMA，低于Wimax，因此LTE信号的峰均比会高于WCDMA，低于Wimax。RRU关键技术四：AQMC技术FDD RRU采用了AQM技术，为了克服AQM的D

22、C offset和IQ unbalance的缺陷，因此加入了AQMC技术AQM的好处在于，降低了对DAC器件性能的要求；降低了中频滤波器的性能要求和设计难度；可以省去射频滤波器。AQMC技术类似于DPD技术，但是与DPD技术相互独立RRU关键技术五：VGA技术由于接收机系统存在邻道、阻塞信号，也存在灵敏度的小信号，为了使射频通道能够兼顾大信号和小信号的情况，在接收机系统中加入VGA技术通过VGA的调整，可以保证大信号情况下，ADC不饱和，射频链路满足线形要求。RRU关键技术六：AGC技术AGC技术是接收机中的重要技术由于接收信号有强有弱，为了保证接收信号以有限位宽传送给基带，并且保证足够的信噪比，需要在接收机中加入AGC技术RRU关键技术七：智能天线技术（TDD）LTE 协议主要内容RRU基本原理射频基本原理目录发射机（高中频）典型系统框图发射机（零中频）典型系统框图接收机典型系统框图频综/时钟（锁相环）典型框图射频的主要性能指标工作频率增益及增益平坦度噪声系数P1dBIP3相位噪声射频的主要性能指标增益及增益平坦度增益：指输出功率和