Be sure the baseband iq signal paths have sufficiently flat frequency response. Optical iq modulators for coherent 100g and beyond lightwave. Reading inphase and quadrature iq data from a signal. Analog television channels 0 through 72 utilize bandwidths between 54 mhz and 825 mhz. The spinning constellation plot in the far right image indicates that the receiver has lost carrier lock with the rf signal. Analog or digital refers to how the data is modulated. The highperformance demodulator hpd library for labview by olymp engineering. Iq modulator an iq modulator is basically a dual parallel machzehnder dpmz modulator composed of four waveguides. Usrp as a lowcost spectrum analyzer to capture rf signals as baseband iq waveform. Maxim provides the industrys highest linearity, lowest noise modulator and demodulator cores which enable unprecedented levels of dynamic range for wideband systems. Exploiting acceleration features of labview platform for. Labview communications system design software or suite 1. The modulators support dpqpsk or higherorder modulation schemes. Iq gain imbalance in 4qam, 16qam and 64qam signals.
Low power iq modulator for digital communications analog. Highspeed mobile data versions employ nonconstant envelope modulation. Interfacing labview communications to matlab software. The figure below shows a labview example demonstrating the.
In its various forms, iq modulation is an efficient way to transfer information, and it also works well with digital formats. Measuring modulation bandwidth this test determines the maximum modulation frequency that the iq modulator supports. This chapter describes modular programming approach in labview software. This toolkit enables you to modulate and demodulate signals with a variety of modulation schemes including am, fm, pm, ask, fsk, msk, psk, and qam. Ni universal software radio peripheral usrp devices are software defined radios. It covers a wide variety of applications from single polarization intensity modulators to polarization multiplexed iq modulators by simple user reconfiguration in software with a single hardware variant. To use a snippet, rightclick the image, save it to your computer, and drag the file onto your labview diagram. Video demonstration of a softwaredefined radio setup with two usrp n200 modules programmed in labview. This video discusses the basics of an iq modulator, discusses and demonstrates its operation, shows a few typical modulation types as well as. Iq is a common way to represent message signals in modern communication systems. It would be nice to have a working encoder and decoder circuit transmitter and receiver. As figure 2 illustrates, iq gain imbalance distorts an rf signal to the point that a receiver is unable to demodulate it. Labview issue details i am looking for the modulo operation in labview. The main program simply acts as an outline or driver, triggering execution of the program units that accomplish the tasks.
To run labview software, system must have high performance processor. Highperformance demodulator library for labview fpga by. The spectrum of ofdm signal with iq rate 2mhz download. The fm band is divided between a variety of purposes. All modulators and ssb upconverters require that at least one of the input frequency bands carrier or modulation has sufficient power to.
Be sure dac reconstruction filter does not encroach upon the baseband bandwidth. Features up to 400 gbs bit rate integrated modulator driver four auto bias modes dual iq modulator bandwidth options. The next chapter explains how to reconstruct the rfsignal from the iqsignal. The output of the iq modulator is being evaluated with an rf spectrum analyzer, a tektronix rsa3408a, with a frequency bandwidth of 8 ghz and exclusive frequency mask trigger for eventbased capture of transient rf signals. Usrp2920, usrp29 30, usrp29 40, or usrp29 50 most radio stations fall between 88 mhz and 108 mhz ideally an fm antenna, but any small wire may work. Figure 2 illustrate the typical electrode architecture of an iq modulator with its internal structure. All are pinpin compatible, allowing coverage for multiband systems. In previous article of getting started with labview, we have seen about labview and how it can be graphically programmed and executed in computer software level. Signal modulation can be divided into two broad categories.
The future of optical communication requires optical arbitrary waveform generation oawg. Baseband iq waveforms extendible waveform library, class hierarchy. This technique is known as quadrature upconversion, and you can use the. The ability to produce any kind of optical waveform, through the use of an optical modulator and an electrical awg requires better accuracy and reliability. It provides link to download labview vi source code. Protocols for educational software instacoverage core by incquery labs. Therefore, it is a common practice to implement the demodulation. It covers bpsk, qpsk, 16qam and 64qam modulation techniques. A 5mhz, ltelike ofdm modulator written in matlab software will be interfaced with labview communications running on a processor and connected with an ni usrp. Each location is discussed in further detail below. The instructionaluse license is defined as use which meets either of the following criteria. Understanding iq modulation as used in software defined. However as the software has developed, the term labview is now synonymous with the g language. The complete waveform simulation for the aforementioned qpsk modulation and demodulation is given next.
Software defined radio am modulation and demodulation. The iq demodulation preserves the information content in the bandpass signal, and the original rfsignal can be reconstructed from the iqsignal. Iq modulator design needs measurement accuracy, says. Use parametric search to explore tis iq modulators portfolio. Quadrature amplitude modulation qam is the name of a family of digital modulation methods and a related family of analog modulation methods widely used in modern telecommunications to transmit information. Refer to rf for more information about related ni hardware and software products. This page of labview source code covers modulator labview vi and demodulator labview vi. Ni labview modulation toolkit help labview digital. Analog devices iq modulators and demodulators operate at frequencies up to microwave and feature a combination of high performance, broadband operating frequency, and flexibility.
Labview provides the signal processing engine for the modulation and. Already make the video about how to download the labview software and ask modulation using labview. Iq modulation ni rf vector signal analyzers nirfsa 18. The national instruments ni modulation toolkit for labview extends the builtin analysis capability of labview with functions and tools for signal generation, analysis, visualization, and processing of standard and custom modulation formats. Usrp ni 2920 and usrp ni2921 widely implemented with combining labview software. Fsk modulation and demodulation using labview software. Digital iq demodulator with a highspeed adc previous next a conventional analog zeroif intermediate frequency inphase and quadrature iq demodulator uses analog components to translate an rf signal to baseband analog i and q signals before converting it to digital data samples. In any radio that is designed to receive frequency modulated signals there is some form of fm demodulator or detector. The system provides an array of functionality through a flexible, hosted, software asaservice saas that is highly configurable to your business needs.
In the software context, the 3qs approach, iqoqpq is being followed as part of validation and it will be carried out by the operations team, who are ultimately responsible for deploying the software to the production. This article provides a list of commercially available softwaredefined radio receivers. The power of labview lies in the hierarchical nature of the vi. The universal software radio peripheral usrp 2900 board is used to design frequency modulation fm demodulation. Frequency modulation fm is most commonly used for radio and television broadcast. Software defined radio am modulation and demodulation youtube. To run labview software, system must have high performance processor such. In addition, the fm band also includes fm radio, which operates from 88 mhz to 108 mhz. Fm demodulation with iq method ni community national. Design and development of an automated demodulator. Pdf labview interfacing usrp for fm demodulation wai phyo. The most common application is generating rf signals for digital communication systems. Labview modulation toolkit download national instruments.
Pdf simulation of analog modulation and demodulation. Understanding the basics of image and carrier suppression. The system has been designed using the labview communication design suit. The am modulation and demodulation scheme is tested and demonstrated by the transmission of. A block diagram description of an fm transmitter follows. If analog audio data is modulated onto a carrier sine wave, this technology is referred to as analog modulation. To run this example you need an xseries signal analyzer with an ethernet tcpip connection. Iq modulators iq modulators are also commonly referred to as quadrature modulators or qpsk modulators for quadrature phase shift keying. An example for wavelength dependence of dc bias is shown in figure 3 using a commercially available inp iq modulator. Lumentum also offers a range of amplitude and phase modulators that can be used in telecom, catv, and specialty applications. The iq data is written to echopac files with 16 bit signed integer representation of the i and.
Zehnder modulators to ensure stable optimal performance over time and environmental conditions. Performing modulo operation in labview national instruments. Labview modulation toolkit is a software addon for labview with functions and tools for generation, analysis, processing, and visualization of analog and digital modulated signals. Adjustable rf gain through the front panel interface and labview software can be performed. This integration enables the modulation process because phase modulation is fairly straightforward with typical iq modulator circuitry. This image is a labview snippet, which includes labview code that you can reuse in your project. The simulation involves, generating random message bits, modulating them using qpsk modulation, addition of awgn channel noise corresponding to the given signaltonoise ratio and demodulating the noisy signal using a coherent qpsk receiver. Video demonstration of a software defined radio setup with two usrp n200 modules programmed in labview. Performe a inverse fft to convert the frequency domain signals to the time. Labview also provides a host of other facilities including debugging, automated multithreading, application user interface, hardware management and interface for system design. Labview digital modulation documentation ni labview modulation toolkit help labview digital modulation. Digital iq demodulator with a highspeed adc nutaq nutaq. The smart sensor networks are designed using labview software are taken as. Iq modulators are versatile building blocks for rf systems.
If we were to implement every possible combination of demodulation algorithm, carrierrecovery technique, and clock regeneration as a distinct model, the combinatorial explosion of different models would become unmanageable. The external pm laser source couples into a dual iq drive speed mzi modulator for qpsk modulation, with dual broadband modulator drivers which provide highquality, singleended voltages to drive a qpsk linbo3 modulator, with independent control and monitoring on both amplified signals. This example codebase of labview apis aids radar design and. The niusrp fetch rx data vi allows you to retrieve iq data from a usrp that has an. One modulation technique that lends itself well to digital processes is called iq modulation, where i is the inphase component of the waveform, and q represents the quadrature component. Radio station reception not a good demo for the basement, use the video hardware. Pc and labview programs, to digitally generate i and q signals. Modern high bit rate optical communication channels now use polarization, amplitude and phase of the optical carrier to encode digital information. This article illustrates the modulation accuracy of the ltc5599 low power iq modulator, and shows by simple example how to integrate the device into a digital communication system. Labview interfacing usrp for fm demodulation zambrut. Iq,transmit power,power spectrum labview vi labview.
The usage of labview software and its vi programs are explained in this paper and it has taken as reference 19. To interface labview with arduino, you require the following softwares and hardwares. Modulation changes a higher frequency carrier signal in proportion to a. What are iq oq pq, the 3 qs of software validation process. We have had other talks about software defined radio and iq modulation. A duc prepares the signals for the dac after which iq mixing. Usrp ni2920 and usrp ni2921 widely implemented with combining labview software. As described in the modulation topic, there are two fundamental ways. Now in this article we learn about how to interface labview with arduino board. Iq coordinator is comprised of distinct system modules that address autonomous but integrated business processes.
Characterization of iq modulators counts on flexible. With this toolkit, you can rapidly develop custom applications for research. It conveys two analog message signals, or two digital bit streams, by changing modulating the amplitudes of two carrier waves, using the amplitudeshift keying ask digital modulation. If i get enough of an understanding, i would like to demonstrate this for our amateur radio club. Modulator and demodulator labview vibpsk,qpsk,16qam,64qam. Software defined radio, equalization and performance analysis. Modulator and demodulator labview source codebpsk,qpsk,16qam,64qam. Iq, transmit power, power spectrum labview vi source code. National instruments labview is an industryleading graphical software tool for designing test, measurement, and automation systems. This page of labview source code covers iq, transmit power and power spectrum labview vis. The spectrum of fm from 70mhz to 7ghz can be inputed to usrp 2900 which acting as software defined radio device. The success of a software depends on the successful completion of iqoqpq. Fm demodulator circuits are found in any receiver that uses fm.
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