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A Low-Cost, 2.3 - 2.5GHz, Software-Defined RF Transceiver SystemPublish Date: Jan 20, 2010

OverviewThis tutorial describes how to combine the NI PCI-5640R IF Transceiver module with the Texas Instruments TSW-5002 RF/Analog transceiver reference design to create a software-configurable RFtransceiver system. The tutorial will outline the required system components, connections, software examples, and applications.

Table of ContentsOverview

The System and Components

Connecting and Configuring the System

For More Information

1. OverviewWireless communication has become increasingly prevalent in the past decade, and with thousands of RF devices now on the market, the ability to communicate these devices has grown inimportance. National Instruments has partnered with Texas Instruments to offer a low-cost, software-defined RF transceiver system that can operate in the 2.3 – 2.5GHz range and communicatewith a vast array of wireless devices. By combining the with the , we are able to implement a solution thatNI PCI-5640R Texas Instruments® TSW-5002EVM RF/Analog transceiver reference designis fully-configurable in LabVIEW and capable of applications from simple RF signal generation and spectrum analysis to the design of RF communications systems. By utilizing the configurability ofLabVIEW, along with the use of the Spectral Measurements Toolkit and Modulation Toolkit, the possibilities of this transceiver system are endless. This technical application note will briefly describethe components involved, and give detailed instructions on how to set up and implement a low-cost, software-defined 2.3 – 2.5GHz RF transceiver system.

Figure 1

2. The System and ComponentsFigure 1 illustrates the required components in the transceiver system, as well as the interface between components. See details below descriptions of each individual component.

Wireless DeviceThis device can be any communication component that operates in the 2.3GHz to 2.5GHz frequency range.

AntennaAny antenna that operates in the 2.3 – 2.5GHz range is acceptable.

Recommendation

Hawking Technology HAI7SIP Hi-Gain 7dBi Omni-Directional Antenna ®

Figure 2

This 2.4GHz WiFi antenna can amplify a standard 2dBi signal to 7dBi. If using this antenna, you will also need the Hawking HACSA MCX to SMA Jumper Cable, since the up/down converter modulehas an MCX antenna connection.

Up/Down ConverterThe up/down converter stage is required to convert from IF to RF in transmit mode and from RF to IF in receive mode.

Recommendation

Texas Instruments TSW-5002EVM Up/Down Converter Reference Design ( ).more info

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Texas Instruments TSW-5002EVM Up/Down Converter Reference Design ( ).more info

Figure 3

The block diagram for the TSW-5002EVM can be seen in Figure 3. The Texas Instruments TSW-5002EVM is an RF/Analog transceiver reference design module operating in TDD mode at the 2.3 –2.5GHz band. It includes the TRF1121 - a TX IF upconverter, the TRF1122 - a TX RF upconverter, the TRF1123 – a TX power amplifier, the TRF1112- an integrated LNA and down mixer and theTRF1115- an RX IF downconverter. The module is designed to merge with a digital baseband processing card, but for stand alone evaluation, the reference board can be merged with the interfaceboard to facilitate programming and piping RF signals into and out to RF equipment. In the procedures outlined in this application note, we will be using the reference board coupled with the interfaceboard, and programming the board through the parallel port interface. The following are descriptions of the individual sub-components required by the TSW-5002EVM device.

Power SupplyFor this transceiver system, the up/down converter module requires two 6VDC banana plug power connections and a combined 1.5A. Any power supply that meets these specifications isacceptable.

Recommendation

MASTECH HY1803D Variable Output DC Power Supply®

Figure 4

This supply has adjustable regulated output voltage from 0-18VDC, adjustable output current from 0-3A, and banana plug outputs (cables not included).

Note that applying a voltage higher than 6.3V could permanently damage the board.

Additional Recommendation

Radio Shack Model 273-1763 6V/1800mA AC-to-DC Power Adapter®

Figure 5

This adapter is low-cost and capable of supplying the 6V and combined 1.5A needed by the TSW-5002EVM Module. It is not a regulated supply, however, and might be limited in supply currentduring transmission operation. If you use this power supply, you will need to convert the output leads to a banana plug form factor. You can use the Radio Shack Adaptaplug Accessory, model273-1742, and then solder banana plug leads to these wires.

CablesIn addition to banana plug cables for the power supply, two SMA cables are needed to connect the up/down converter module to the PCI-5640R IF module. The cables must be rated up to 2.5GHzand have male SMA connections on each end.

Recommendation

NI SMA100 cable

Figure 6

This cable is available in 15cm (part number 763443-01) and 45cm (part number 763444-01) lengths.

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This cable is available in 15cm (part number 763443-01) and 45cm (part number 763444-01) lengths.

IF TransceiverThe IF transceiver module processes and generates baseband signals.

Required

NI PCI-5640R Software Defined Radio IF Transceiver

Figure 7

Figure 7 shows a block diagram of the , which is a 2-channel IF input/2-channel IF output PCI board with a Xilinx FPGA. The PCI bus interface is provided by the NI DAQ-STC2 ASIC,NI PCI-5640Rwhich has four DMA channels that are able to transport streams between the host CPU (PC) and the Xilinx FPGA. Digital upconversion and digital downconversion are done within the ADCs/DACs,thus offloading the Xilinx FPGA. The device has 14bits of resolution and a 100MS/s maximum sampling rate for analog input and a 200MS/s update rate for analog output.

Follow this for more information about the NI PCI-5640R.link

PC and SoftwareThe NI PCI-5640R plugs into a desktop PC through a standard PCI interface and requires a full-length PCI slot. The TSW-5002EVM module communicates through the computer’s parallel port. Drivers, example programs, and a software development environment are also required components on the PC.

Recommendation

Dell Precision 380, 2.99 GHz Pentium 4, 1GB RAM with Parallel Port

Figure 8

The software-defined transceiver system is fully-configurable with . To create a full RF communications system, you will also need the and the NI LabVIEW NI Spectral Measurements Toolkit NI. Please refer to the NI-5640R Readme file, which is available on the NI-5640R CD or by downloading the , for more information on system requirements.Modulation Toolkit NI-5640R driver

3. Connecting and Configuring the SystemOnce you have obtained the required components, you are ready to connect and configure the RF transceiver system. The following instructions will guide you through the setup process.

Consult the for information on how to install the software and hardware for the NI-5640R.NI-5640R IF Transceiver Getting Started Guide

Set up the TSW-5002EVM up/down converter deviceConnect the TSW5002 baseband processing card to the TSW5002 RF up/down converter card. The up/down converter card receives the RF signal from the antenna and then feeds it tothe baseband processing card, which has all of the I/O terminals for the TSW5002 module. Together, the two cards make up the TI up/down converter module. Connect the two cards suchthat the heat sink on the RD up/downconverter card is facing down and the antenna port is facing up.

Connect the baseband processing card to your computer using the supplied parallel cable.

Since we will not be supplying an external RXAGC voltage, move jumper W1 to read from the potentiometer (POT) instead of the external connection (1 EXT).

Download software for up/down converterNavigate to the example program on the titled " "NI Developer Zone Configuration Utility for TSW-500x Devices (to Create an RF Transceiver System with the NI PCI-5640R)

Download the configure_tsw500x.zip file

Connect WiFi antenna and power supplyConnect the Hawking SMA to MCX adapter to the SMA connector on the antenna, then insert the MCX plug on the adapter into the MCX connector on the up/down converter card.

Use a banana cable to connect the ground terminal on your power supply to the J9 (GND) connection on the baseband processing card

Connect the power supply’s positive line to J10 (VDD_EXT) and J11 (VDD_PA) on the baseband processing card (you will need to daisy chain two banana cables since there is only onepositive output on the power supply and two 6V connections on the device).

You are now ready to begin acquiring or generating RF signals. The following sections describe how to implement a Receiver System and a Transmitter System, respectively, for the 2.3 – 2.5GHzfrequency range. Note that if two TSW-5002EVM modules are available, one can perform simultaneous receiver and transmitter operations.

Receiver SystemRx5. Configure the up/down converter acquisition

Navigate to the Configure_TSW500x example VI that was downloaded in step 4.

Open the Block Diagram of Spectrum Analyzer.vi. Insert the Configure_TSW500x.vi into the block diagram between the ni5640R Get Actual IQ Rate.vi and the While Loop as shown in Figure 9below. When modifying example programs, be sure not to overwrite the example. Select File » Save As… and choose “Substitute copy for original” to save the VI under a different name.Note:

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Figure 9

Wire the error cluster through the Configure_TSW500x.vi.

Create a constant for 2G5/3G5 and set to False (TSW-5002EVM).

Create a constant for RX RF Frequency (MHz) and enter the center frequency of the signal you are receiving.

Create a constant for Filter Select and LNA Attn. Toggle the Filter Select boolean to switch between two 44MHz filters that have different bandwidth: 3.5MHz and 7MHz. Toggle the LNA Attnboolean to engage or disengage the bypass on the second LNA stage.

Create a constant for One_shot? and set to True.

Rx6. Use an SMA cable to connect J3 (RXOUT) from the up/down converter module to Analog Input Channel 0 on the back of the PCI-5640R device.

Rx7. Configure the IF transceiver acquisition

Open the Spectrum Analyzer.vi example program for the NI PCI-5640R, which can be found at Start » Programs » National Instruments » NI-5640R » Examples » LabVIEW 8.2. The front panelfor this example program can be seen below in Figure 10.

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Figure 10

Choose your device from the drop down menu. If you specified a VISA alias for your IF transceiver in MAX, you will see that name in the drop down menu.

Enable channel 0 and specify a center frequency of 44MHz (this is the RX baseband frequency of the up/down converter). Choose a span that is appropriate to your signal. The default valuesfor the other controls can remain unchanged.

Rx8. Generate RF signal and begin acquisition

Begin generation of your RF signal (using external wireless or other device) at the frequency you specified for the RX RF Frequency (MHz) input in step Rx8.

Run the Spectrum Analyzer.vi. You can now see the acquired spectrum in the Channel 0 Spectrum display. In Figure 11 below, we are receiving a 2.4GHz tone. The Frequency (Hz)Note:axis is relative to the specified Center Frequency (Hz).

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Figure 11

Transmitter SystemTx5. Use an SMA cable to connect J2 (TXIN) from the up/down converter module to Analog Output Channel 0 on the back of the PCI-5640R device.

Tx6. Configure the IF transceiver generation

Open the Single Tone Generation.vi example program for the NI PCI-5640R, which can be found at Start » Programs » National Instruments » NI-5640R » Examples » LabVIEW 8.2. The frontpanel for this example program can be seen below in Figure 12.

Figure 12

Choose your device from the drop down menu. If you specified a VISA alias for your IF transceiver in MAX, you will see that name in the drop down menu.

Enable channel 0 and specify a carrier frequency of 18MHz (this is the TX baseband frequency of the up/down converter).

Set the power level (dBm) to -20. This is the input specification for the up/down converter.

Tx7. Configure the up/down converter acquisition

Navigate to the Configure_TSW500x example VI that was downloaded in step 4.

Open the Block Diagram of the Single Tone Generation.vi. example program. Insert the Configure_TSW500x.vi into the block diagram between the ni5640R Write Waveform.vi and the ni5640RInitiate.vi (steps 3 and 4, respectively) as shown in Figure 13 below. When modifying example programs, be sure not to overwrite the example. Select File » Save As… and chooseNote:“Substitute copy for original” to save the VI under a different name.

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Figure 13

Wire the error cluster through the Configure_TSW500x.vi.

Create a constant for 2G5/3G5 and set to False (TSW-5002EVM).

Create a constant for TX RF Frequency (MHz) and enter the frequency of the signal you wish to generate.

Create a constant for TX Digital Attn. This value is defaulted to 15dB and can be adjusted to obtain the desired output power. maximum output power does not correspond to 0dBNote:attenuation. The maximum rated output power is 20dBm modulated and generally corresponds to a digital attenuator setting between 2 and 10dB.

Create a constant for TX On and PA On and set each to True.

Create a constant for One_shot? and set to True.

Tx8. Generate RF signal and receive through wireless device

Run the modified Single Tone Generation.vi to generate a baseband tone at 18MHz and upconvert to the frequency specified in the TX RF Frequency (MHz) block diagram constant.

Use your wireless device to receive the tone.

These examples demonstrate basic receiver and transmitter operation. However, fully-functional, complex systems can be programmed in LabVIEW. With the use of the NI 5640R driver, theSpectral Measurements Toolkit, and the Modulation toolkit, you can create an intricate, software-defined communications system that is tailored to the specific needs of your application andenvironment.

4. For More InformationVisit the RF Homepage

Read more about the Software Defined Radio IF TransceiverNI PCI-5640R

Download the NI-5640R Instrument Driver

Programming the TI TSW-5002EVM RF/Analog transceiver reference design with LabVIEW: "Configuration Utility for TSW-500x Devices (to Create an RF Transceiver System with the NI"PCI-5640R)

Learn about the (links to the TI website).Texas Instruments® TSW-5002EVM RF/Analog transceiver reference design