This example shows how to use the rtlsdr radio, with matlab and simulink, as a data source for downstream spectrum analysis. Increasing the sweep time or reducing video bandwidth both increase the amount of averaging that occurs in each fft bin, which can help reduce noise in the measurement. You clicked a link that corresponds to this matlab command. Lte downlink adjacent channel leakage power ratio aclr measurement.
Frame size is the first dimension of the input vector. This article will demonstrate the use of matlab on the anritsu signature ms2781a signal analyzer to automate an acpr adjacent channel power ratio versus. Measurement of adjacent channel leakage power on 3gpp wcdma. Understanding adjacent channel power measurements in. Measure the peaks, cursor placements, adjacent channel power ratio, distortion, and ccdf values in the spectrum by enabling the following properties.
Lte downlink test model etm waveform generation matlab. Configure spectrum analyzer block matlab mathworks nordic. Aclr is used as a measure of the amount of power leaking into adjacent channels and is defined as the ratio of the filtered mean power centered on the assigned channel frequency to the filtered mean power centered on an adjacent channel. Engineers require software that provides the ability to interface designs or algorithms with live signals using test and measurement equipment for. When you run the example, you can measure signal characteristics such as peaks, occupied bandwidth, adjacent channel power ratio, harmonic and intermodulation levels, and spurfree dynamic range. The overflow logical output indicates whether any output samples are not contiguous. Spectrum analyzer measurements base software channel power, adjacent channel power, multicarrier adjacent channel power leakage ratio, occupied bandwidth, xdb down, marker measurements of power, delta power, integrated power, power density, dbmhz, and dbchz, signal strength with audible feedback. Acpr is the ratio of signal power measured in an adjacent frequency band to the power from the same signal measured in its main band. The model includes two interferers, interferer 1 and interferer 2. How the adjacent channel leakage power ratio aclr can be measured within a downlink reference measurement channel rmc signal using the lte toolbox. Improving channel power, adjacent channel power, and occupied bandwidth measurements a number of strategies exist for making stable cp measurements.
Plot the adjacent channel power ratios for a range of adjacent channel offsets. Adjacent channel leakage power ratio aclr is the ratio of the transmitted power to the power measured after a receiver filter in the adjacent channel s. A steph,x returns a vector of the adjacent channel power ratio, a, measured in the input data, x. Using a signal analyzer and matlab to measure acpr. Acprname, value creates object, h, with each specified property set to the specified value. Acpr and ccdf measurements with matlab system objects.
Download scientific diagram example of adjacent channel power ratio acpr improvement with dpd iii. Cursors measure signal values using vertical and horizontal cursors peak finder find maxima, showing the xaxis values at which they occur channel measurements measure the occupied bandwidth or adjacent channel power ratio acpr distortion measurements measure harmonic distortion and intermodulation distortion. Measurement of adjacent channel leakage power on 3gpp. Get the current measurement data displayed on the spectrum. Figure 1 is the screen image of an agilent n9020a mxa signal analyzer performing an aclr measurement of a wcdma signal. The effects of adjacent and co channel interference on a psk modulated signal. The example contains a typical setup to perform harmonic distortion measurements thd, snr, sinad, sfdr, thirdorder intermodulation distortion measurements toi, adjacent channel power ratio measurements acpr, complementary cumulative distribution function ccdf, and peak to average power ratio papr. The relationship between adjacent channel power ratio and.
Spectral analysis is the process of estimating the power spectrum ps of a signal from its timedomain representation. Compute and display the power spectrum of a noisy sinusoidal input signal using the dsp. Acquire and analyze overtheair received signals in matlab using rf instruments or software. Dsp system toolbox includes the spectrum analyzer software componentone in a set of multichannel streaming scopes. You can change the radios center frequency to tune the radio to a band where a signal is present. I know something is wrong as when i look at a similar situation on a real spectrum analyzer there is only power centered around the carrier. Sfdr, thirdorder intermodulation distortion measurements toi, adjacent channel power ratio measurements acpr, complementary cumulative distribution function ccdf, and peak to average power ratio papr. You can specify additional namevalue pair arguments in any order as name1,value1. The spike software provides cpacp measurement capabilities through the control panel that only requires a user to input the centertocenter frequency difference between the center channels and adjacent channel, bandwidth of each channel, and number of adjacent channel. This setting is available only if you select acpr as the measurement type. The spectrum analyzer software computes and displays the spectrum, power density spectrum, and spectrogram for variety of signals and data types, including audio, biosignals, communication signals, speech, and streaming data. Mar 19, 2015 when the power of acpr is around 20 db, which is equal to the snr we set in awgn channel block, the channel powers showed in spectrum analyzer is around20 db, which i expect to be around 30 db for referencing to 1 watts should result in30 db. Support for npusch channel processing and drs generation. Display frequency spectrum of timedomain signals matlab.
Perform measurements using the spectrum analyzer block. The model enables you to modify the frequency offset and the power gain of each interferer, and view the effects on a spectrum plot. This example performs adjacent channel leakage power ratio aclr measurements according to ts36. Adjacent channel power ratio acpr calculations also known as adjacent.
Adjacent channel leakage power ratio aclr, operating band unwanted emissions, transmitter spurious emissions. This is giving me incorrect values on my adjacent channel power ratio calculation as when i add nonsine wave modulation, power from this second band is included in my calculation. Example of adjacent channel power ratio acpr improvement with. Adjacent channel power ratio measurements matlab mathworks.
Dsp system toolbox provides algorithms, apps, and scopes for designing, simulating, and analyzing signal processing systems in matlab and simulink. Jun 07, 2005 this is giving me incorrect values on my adjacent channel power ratio calculation as when i add nonsine wave modulation, power from this second band is included in my calculation. Spectrum analyzer software with matlab and simulink. The example also shows how to view timevarying spectra by using a spectrogram and automatic peak detection. With spectrum analyzer, engineers visualize, measure, and analyze the frequency domain characteristic of evolving multichannel signals or streaming data in realtime during simulation in matlab or simulink. This example shows how to perform transmitter test measurements specific to output power and inband emissions on bluetooth r low energy ble transmitted waveforms as per the bluetooth rfphy test specifications 1 using communications toolbox library for the bluetooth protocol. An adaptive digital predistortion for compensating nonlinear. Obtain measurements data programmatically for spectrum. Citeseerx document details isaac councill, lee giles, pradeep teregowda. This matlab function returns a data table about the current spectrum analyzer measurements in use. This example shows how to perform measurements using the spectrum analyzer block. The acpr system object measures adjacent channel power ratio acpr of an input signal. The user interface, features, and measurements are consistent with conventional hardwarebased spectrum analyzers. Lte downlink adjacent channel leakage power ratio aclr measurement how the adjacent channel leakage power ratio aclr can be measured within a downlink reference measurement channel rmc signal using the lte toolbox.
Vector and rf suite of signal analysis software for pc. An adaptive digital predistortion for compensating. You can model realtime dsp systems for communications, radar, audio, medical devices, iot, and other applications. Ccdf measurements measure the complimentary cumulative distribution function. The wcdma standard specifies acpr limits for four adjacent channels, located at 5, 5, 10, 10 mhz away from the main channel center frequency. N9000b cxa signal analyzer, multitouch, 9 khz to 26. Evm and adjacentchannel power ratio acpr ieee xplore. Spectrum analyzer software with matlab and simulink matlab.
For example, cdma2000 adopted adjacent channel power ratio acpr and. This paper further validates the psi technique through experimental measurement with a power amplifier pa test bench and achieves an adjacent channel power ratio acpr of less than 55 dbc. Recall that you must first release hacpr to change the offset. The outofband emission requirements for the evolved node b enb and user equipment ue transmitters, for instance, are specified in terms of both adjacent channel leakage power ratio aclr and unwanted emissions on the operating band. Display frequency spectrum simulink mathworks benelux. The behavior of step is specific to each object in the toolbox. Understanding adjacent channel power measurements in spectrum.
Specify adjacent channel offsets and measurement bandwidths. Using a signal analyzer and matlab to measure acpr versus power. Using a signal analyzer and matlab to measure acpr versus. Acpr creates a system object, h, that measures adjacent channel power ratio acpr of an input signal. Set the channel offsets to range from 30 khz to 70 khz in 10 khz steps. It has bestofclass dynamic range average noise level danl. Lte downlink adjacent channel leakage power ratio aclr measurement lte evm and inband emissions measurements. Abstract in this paper, an adaptive digital predistortion based on a memory polynomial model is proposed in order to linearize the power amplifier with memory effect. With dsp system toolbox you can design and analyze fir, iir, multirate, multistage, and adaptive filters. The example contains a typical setup to perform harmonic distortion measurements thd, snr, sinad, sfdr, thirdorder intermodulation distortion measurements toi, adjacent channel power ratio measurements acpr, complementary cumulative distribution function ccdf, and peak to average power ratio. The tradeoff between linearity and efficiency in the power amplifier has been broken by a proposed structure. Channel measurements measure the occupied bandwidth or adjacent channel power ratio acpr. Compute and display the power spectrum of a noisy sinusoidal input signal using the spectrum analyzer block. Offset hz the center frequency of the adjacent channel with respect to the center frequency of the main channel.
Measure the peaks, cursor placements, adjacent channel power ratio, distortion, and ccdf values in the spectrum by enabling these block configuration properties. See construction call step to measure the adjacent channel power ratio according to the properties of comm. This shows that the computer program by matlab is useful to rfmicrowave system engineers in the design of power amplifiers for digital wireless communications. Adjacent channel power ratio acpr calculations also known as adjacent channel. I have an original image and a distorted image of the original one. Adjacent channel power ratio acpr adjacent channel power ratio acpr calculations also known as adjacent channel leakage ratio aclr, characterize spectral regrowth in a communications system component, such as a modulator or an analog front end.
The criterion of adjacent channel power ratio acpr has been improved by around 15 db. Adjacent channel power ratio acpr calculations also known as adjacent channel leakage ratio aclr, characterize spectral regrowth in a communications system component, such as a modulator or an analog front end. Adjacent channel leakage power ratio aclr is the ratio of the transmitted power to the power measured after a receiver filter in the adjacent channels. Distortion measurements measure harmonic distortion and intermodulation distortion.
Adjacentchannelpower acp measurements are hardly new, but several. The aclr measurement is defined as the relative power in the adjacent and alternate channels to the amount of power in the carrier measured in a 3. This example shows how to measure the adjacent channel power ratio acpr from a baseband, 50 kbps qpsk signal. Use of a memory polynomial model has been suggested in order to model the power amplifier and a digital predistortion. Ble output power and inband emissions test measurements. I want to calculate the psnr of the distorted image, so that i can measure the distortion in db. Both the transmitted power and the received power are measured with a filter that has a rootraised cosine rrc filter response with rolloff. The spectrum analyzer system object displays the frequency spectrum of timedomain signals. This scope supports variablesize input, which allows the input frame size to change.
This example shows how the adjacent channel leakage power ratio aclr can be measured within a downlink reference measurement channel rmc signal using the lte toolbox. The measurements are at the frequency bands that you specify with the mainchannelfrequency, mainmeasurementbandwidth, adjacentchanneloffset, and adjacentmeasurementbandwidth properties. This example shows how the adjacent channel leakage power ratio aclr can be measured within a downlink reference measurement channel rmc. Complementary cumulative distribution function ccdf. Realtime decoding of automatic dependent surveillance. Occupied bandwidth, adjacent channel leakage power ratio aclr, operating band unwanted emissions, transmitter. Transmit lte waveforms from matlab using rf instruments or software defined radios sdr. How to measure adjacent channel leakage power ratio aclr the ms2830a is a spectrum analyzersignal analyzer with topclass measurement speed at mediumclass price. The aclr is the ratio of the filtered mean power centered on the assigned channel frequency to the filtered mean power centered on an adjacent channel.
Verifying lte designs using live signals and test and measurement equipment a key requirement for lte or lteadvanced system design and verification is the ability to work with live lte signals. Define and set up your adjacent channel power object. You then test the cnn with softwaredefined radio sdr hardware and. In all cases, you obtain adjacent channel power using a 3. How to measure adjacent channel leakage power ratio aclr.