Introduction

在此示例中，LTE工具箱用于生成标准基带IQ下行链路测试模型（E-TM）波形。使用仪器控制工具箱，将所生成的波形下载到Keysight Technologies N5172B信号发生器，用于过空气传输。使用Keysight Technologies N9010A信号分析仪捕获过空中信号。

For more information on LTE waveform generation and analysis, refer to使用测试和测量设备的LTE工具箱的波形生成和传输(LTE Toolbox)。

Requirements

要运行此示例，您需要：

Generate a Baseband Waveform Using the LTE Toolbox

Generate test model waveform usingLTetestModeltool.(LTE Toolbox)那this returns an E-TM time-domain waveform,波形，在单个天线端口跨越多个子帧的资源元素的2-D数字数组，tmgrid.和标量结构，tmconfig，包含有关OFDM调制波形的信息。

config = lteTestModel('1.1'那'5MHz'）;％测试型号1.1，5MHz带宽config.totsubframes = 100;％生成100个子帧[波形，Tmgrid，TMConfig] = LTTESTMODELTOOL（CONFIG）;

The frequency spectrum of the generated time domain waveform,波形那can be viewed using thedsp.spectrumanalyzer.(DSP System Toolbox)。As expected, the 5MHz signal bandwidth is clearly visible at baseband.

％计算LTE信号中的光谱内容SpectRumplottX = DSP.SpectRumanalyzer;spectumplottx.samplerve = tmconfig.samplingrate;spectrumplottx.spectrumtype ='Power density';spectrumplottx.powerunits =.'dbm';spectrumPlotTx.RBWSource ='财产';spectrumPlotTx.RBW = 15e3; spectrumPlotTx.FrequencySpan ='Span and center frequency';spectrumplottx.span = 7.68e6;spectrumplottx.Centerfrequency = 0;spectrumplottx.window ='长方形';spectrumplottx.spectralaverages = 10;spectrumplottx.ylimits = [-100 -60];spectrumplottx.ylabel ='psd';spectrumplottx.title ='Test Model E-TM1.1, 5 MHz Signal Spectrum';spectrumplottx.showlegend = false;Spectrumplottx（波形）;

Generate an Over-the-Air Signal using Quick-Control RF Signal Generator

快速控制RF信号发生器用于下载并传输由LTE工具箱创建的测试模型波形，波形那using the Agilent Technologies N5172B signal generator. This creates an RF LTE signal with a center frequency of 1GHz. Note 1GHz was selected as an example frequency and is not intended to be a recognized LTE channel.

创建RF信号发生器对象

rf = rfsiggen（）;

发现您可以使用的所有可用仪器资源，使用resourcesmethod.

RF.。resources

ans ='asrl1 :: instrsssrl3 :: instrssasrl :: com1 asrl :: com3 tcpip0 :: 172.28.21.217 :: inst0 :: instr'

Discover all the available instrument drivers, using司机method.

RF.。司机

ANS ='驱动程序：AGRFSIGGEN_SCPI支持的型号金宝app：E4428C，E4428C驱动程序：RSRFSIGGEN_SCPI支持的型号：SMW200A，SMBV100A，SMU200A，SMJ100A，AMU200A，SMATE200A驱动程序：AGRFSIGGEN支持的型号：E4428C，E4438C，N5181A，N5171B，N5181B，N5171B，N5181B，N5172B，N5181B，N5172BN5182B，N5173B，N5183B，E8241A，E8244A，E8251A，E8254A，E8247C'

放Resourceand司机连接到对象之前的属性。Keysight Technologies N5172B信号发生器的IP地址是172.28.21.217因此，指定的资源将是'tcpip0 :: 172.28.21.217 :: inst0 :: instr'

rf.resource ='TCPIP0 :: 172.28.21.217 :: Inst0 :: instr';RF.。司机='Agrfsiggen';% Connect to the instrument连接（rf）;

Download the waveform,波形，仪器

download(rf, transpose(waveform), tmconfig.SamplingRate);

称呼开始to start transmitting waveform using specifiedcenterFrequency那输出功率andloopcount.。Loop count represents the number of times the waveform should be repeated.

centerFrequency = 1e9; outputPower = 0; loopCount = Inf; start(rf, centerFrequency, outputPower, loopCount);

可以使用调谐到1GHz中心频率的频谱分析器来观察由信号发生器发送的RF信号的频谱。下面的屏幕截图，来自Agilent Technologies N9010A信号分析仪，清楚地显示了5MHz信号带宽。

清理

当您完成传输数据时，停止波形输出，断开连接RFSIGGEN.来自信号发生器的对象，并将其从工作区中删除。

停止（rf）;断开（RF）;清除RF.