comm.SDRTxE3xx

Send data to USRP E3xx radio hardware

Add-On Required: This feature requires the Communications Toolbox Support Package for USRP Embedded Series Radio add-on.

Description

The comm.SDRTxE3xx System object™ sends data to a USRP™ E3xx radio hardware.

The object supports these radio hardware devices:

• USRP E310

• USRP E312

You can use the comm.SDRTxE3xx System object to simulate and develop various software-defined radio (SDR) applications. This diagram shows the conceptual overview of transmitting and receiving radio signals in MATLAB^® using the Communications Toolbox™ Support Package for USRP Embedded Series Radio. MATLAB interacts with the comm.SDRTxE3xx transmitter System object to send data to the radio hardware.

To send data to the E3xx radio hardware:

1. Create the comm.SDRTxE3xx object and set its properties.

2. Call the object with arguments, as if it were a function.

To learn more about how System objects work, see What Are System Objects?

Creation

To create a default comm.SDRTxE3xx System object, use the sdrtx function with input argument 'E3xx'. For example:

tx = sdrtx('E3xx')

To create the object with properties set to specific values, call the function using one or more name-value arguments. For example:

tx = sdrtx('E3xx', ...
           'IPAddress','192.168.3.2', ...
           'CenterFrequency',2.2e9, ...
           'BasebandSampleRate',800e3);

Properties

The comm.SDRTxE3xx transmitter System object supports up to two channels to send data to the E3xx radio hardware. Use the ChannelMapping property to indicate whether to use a single channel or both channels. For each channel, you can set the Gain property independently, or you can apply the same setting to both channels. If you select direct digital synthesis (DDS) transmission for the DataSourceSelect property, you can also set all DDS-based properties independently. All other property values are applied to each channel in use.

Unless otherwise indicated, properties are nontunable, which means you cannot change their values after calling the object. Objects lock when you call them, and the release function unlocks them.

If a property is tunable, you can change its value at any time.

For more information on changing property values, see System Design in MATLAB Using System Objects.

Main Properties

IPAddress — IP address of radio hardware

'192.168.3.2' (default) | dotted-quad character vector

IP address of the radio hardware, specified as a dotted-quad character vector. This value must match the physical IP address of the radio hardware assigned during hardware setup. For more information, see Guided Host-Radio Hardware Setup. If you configure the radio hardware with an IP address other than the default, update the IPAddress accordingly.

Data Types: char | string

CenterFrequency — RF center frequency in Hz

2400000000 (default) | nonnegative finite scalar

RF center frequency in Hz, specified as a nonnegative finite scalar. The valid range for center frequency is 70 MHz to 6 GHz.

Tunable: Yes

Data Types: double

ChannelMapping — Channel input mapping

1 (default) | 2 | [1 2]

Channel input mapping, specified as one of these values:

• 1 — Only channel 1 is in use.

• 2 — Only channel 2 is in use.

• [1 2] — Both channels are in use.

Gain — Gain in dB

-10 (default) | numeric scalar | 1-by-2 vector

Gain in dB, specified as a numeric scalar or a 1-by-2 numeric vector. The valid range for gain is from –89.75 dB to 0 dB. The resolution is 0.25 dB.

Set the gain based on the ChannelMapping property.

• For a single channel, specify the gain as a scalar.

• For two channels that use the same gain value, specify the gain as a scalar. The object applies the gain by scalar expansion.

• For two channels that use different gain values, specify the gain as a 1-by-2 vector. The ith element of the vector is applied to the ith channel specified by the ChannelMapping property.

Tunable: Yes

Data Types: double

BasebandSampleRate — Baseband sampling rate in Hz

1000000 (default) | positive scalar

Baseband sampling rate in Hz, specified as a positive scalar. The valid range of this property is 520.834 kHz to 30.72 MHz.

Note

To synchronize the comm.SDRTxE3xx System object with the radio hardware, call the info function on the object. If the specified and actual rates have a small mismatch, verify that the computed rate is close to the value you actually want.

Data Types: double

Filter

UseCustomFilter — Use custom filter

false (default) | true

Use custom filter, specified as one of these values:

• false — The filter chain uses the default filter design.

• true — The filter chain uses a custom filter design. For example, if the gain or bandwidth characteristics of the default filter does not satisfy the requirements for your application, you can design a custom filter that meets your specific requirements. To design a custom filter, call the designCustomFilter function.

Note

When applying a custom filter to a comm.SDRTxE3xx System object, the UseCustomFilter property is automatically set to true. To switch between the default and your custom filter, set the UseCustomFilter property to false or true, respectively.

For more information, see Baseband Sampling Rate and Filter Chains.

Data Types: logical

Advanced Properties

ShowAdvancedProperties — Enable advanced properties

false (default) | true

Enable advanced properties, specified as false or true.

When you set this property to true, these advanced properties are enabled.

• BypassUserLogic

• DataSourceSelect

• DataTimeout

• BISTLoopbackMode

• BISTToneInject

Data Types: logical

BypassUserLogic — Option for bypassing user logic

false (default) | true

Option for bypassing user logic, specified as false or true. When the property is true, the radio hardware data path bypasses the algorithm generated and programmed during FPGA targeting or hardware-software co-design. For more information, see FPGA Targeting Workflow and Hardware-Software Co-Design Workflow.

Dependencies

To enable this property, set ShowAdvancedProperties to true.

Data Types: logical

DataSourceSelect — Source of data

'Input Port' (default) | 'DDS'

Source of data, specified as 'Input Port' or 'DDS'.

When you select direct digital synthesis ('DDS') as the source of data, the object enables two additive tones for each channel. To set the tone frequency and tone scale of these tones, use the DDSTone1Freq, DDSTone2Freq, DDSTone1Scale, and DDSTone2Scale properties. The DDS signals are generated on the FPGA.

Dependencies

To enable this property, set ShowAdvancedProperties to true.

Data Types: char | string

DDSTone1Freq — First DDS tone frequency in Hz

5000 (default) | numeric scalar | 1-by-2 numeric vector

First DDS tone frequency in Hz, specified as one of these options:

• Numeric scalar — Use this option for a single channel or to specify the same frequency for two channels. The object applies scalar expansion for each channel specified by the ChannelMapping property.

• 1-by-2 numeric vector — Use this option to specify different frequencies for two channels. The ith element of the vector is applied to the ith channel specified by the ChannelMapping property.

The valid range of this property is from 0 to BasebandSampleRate / 2.

Dependencies

To enable this property, set DataSourceSelect to 'DDS'.

Data Types: double

DDSTone2Freq — Second DDS tone frequency in Hz

10000 (default) | numeric scalar | 1-by-2 numeric vector

Second DDS tone frequency in Hz, specified as one of these options:

• Numeric scalar — Use this option for a single channel or to specify the same frequency for two channels. The object applies scalar expansion for each channel specified by the ChannelMapping property.

• 1-by-2 numeric vector — Use this option to specify different frequencies for two channels. The ith element of the vector is applied to the ith channel specified by the ChannelMapping property.

The valid range of this property is 0 Hz to BasebandSampleRate / 2.

Dependencies

To enable this property, set DataSourceSelect to 'DDS'.

Data Types: double

DDSTone1Scale — First DDS tone scale

0.5000 (default) | numeric scalar | 1-by-2 numeric vector

First DDS tone scale in millionths of full scale, specified as one of these options:

• Numeric scalar — Use this option for a single channel or to specify the same scale for two channels. The object applies scalar expansion for each channel specified by the ChannelMapping property.

• 1-by-2 numeric vector — Use this option to specify different scales for two channels. The ith element of the vector is applied to the ith channel specified by the ChannelMapping property.

The valid range of this property is from 0 to 1.

Dependencies

To enable this property, set DataSourceSelect to 'DDS'.

Data Types: double

DDSTone2Scale — Second DDS tone scale

0.2500 (default) | numeric scalar | 1-by-2 numeric vector

Second DDS tone scale in millionths of full scale, specified as one of these options:

• Numeric scalar — Use this option for a single channel or to specify the same scale for two channels. The object applies scalar expansion for each channel specified by the ChannelMapping property.

• 1-by-2 numeric vector — Use this option to specify different scales for two channels. The ith element of the vector is applied to the ith channel specified by the ChannelMapping property.

The valid range of DDSTone2Scale is from 0 to 1.

Dependencies

To enable this property, set DataSourceSelect to 'DDS'.

Data Types: double

DataTimeout — Timeout for I/O operations in seconds

Inf (default) | nonnegative scalar

Timeout for I/O operations in seconds, specified as one of these options:

• Inf — The object waits indefinitely to complete I/O operations.

• Nonnegative scalar, N — The object waits N seconds to complete I/O operations. Zero seconds corresponds to a non-blocking setup.

Dependencies

To enable this property, set ShowAdvancedProperties to true.

Data Types: double

BISTLoopbackMode — Built-in self-test (BIST) loopback mode

'Disabled' (default) | 'Digital Tx -> Digital Rx' | 'RF Rx -> RF Tx'

Built-in self-test loopback mode, specified as one of these options:

• 'Disabled' — Disable BIST loopback.

• 'Digital Tx -> Digital Rx' — Enable digital signals to loop back within the device. The signals bypass the RF stage.

• 'RF Rx -> RF Tx' — Enable incoming receiver RF signals to loop back to the RF transmitter port. The signals bypass the FPGA.

Dependencies

To enable this property, set ShowAdvancedProperties to true.

Data Types: char | string

BISTToneInject — BIST signal injection mode

'Disabled' (default) | 'Tone Inject Tx' | 'Tone Inject Rx'

BIST signal injection mode, specified as one of these options:

• 'Disabled' — Disable BIST signal injection.

• 'Tone Inject Tx' — Enable BIST signal injection to the transmit path.

• 'Tone Inject Rx' — Enable BIST signal injection to the receive path.

When you enable BIST signal injection, you can set the source of BIST signal generation with the BISTSignalGen property.

Dependencies

To enable this property, set ShowAdvancedProperties to true.

Data Types: char | string

BISTSignalGen — Source of BIST signal generation

'PRBS' (default) | 'Tone'

Source of BIST signal generation, specified as one of these options:

• 'PRBS' — Use the pseudo random binary sequence (PRBS) generator of the board.

• 'Tone' — Use the tone generator of the board. To set the tone frequency and tone level, use the BISTToneFreq and BISTToneLevel properties, respectively.

Dependencies

To enable this property, set BISTToneInject to 'Tone Inject Tx' or 'Tone Inject Rx'.

Data Types: char | string

BISTToneFreq — BIST tone frequency

'Fs/32' (default) | 'Fs/16' | 'Fs*3/32' | 'Fs/8'

BIST tone frequency, specified as 'Fs/32', 'Fs/16', 'Fs*3/32', or 'Fs/8'.

Dependencies

To enable this property, set BISTSignalGen to 'Tone'.

Data Types: char | string

BISTToneLevel — BIST tone level

'0' (default) | '-6' | '-12' | '-18'

BIST tone level, specified as '0', '-6', '-12', or '-18'.

Dependencies

To enable this property, set BISTSignalGen to 'Tone'.

Data Types: char | string

Usage

Syntax

tx(data)

tx()

underflow = tx(data)

Description

tx(data) sends data to the radio hardware associated with the comm.SDRTxE3xx transmitter System object, tx.

tx() enables DDS transmission. To use this syntax, set the DataSourceSelect property to 'DDS'.

underflow = tx(data) returns a logical value that indicates data discontinuity. If underflow is true, the input data does not represent contiguous data from the host to the antenna. Use this information to determine whether the host sends valid data to the radio hardware.

Note

Calling the object for the first time initializes the radio. Because this initialization can result in an underflow, ignore the underflow output value of the first call.

Input Arguments

data — Input signal

complex matrix

Input signal sent to the radio hardware, specified as a complex matrix. The number of columns in the matrix depends on the number of channels in use, as specified by the ChannelMapping property. Each column corresponds to a channel of complex data sent on one channel. In single-channel mode, the number of elements in a column must be even.

The complex data type of the transmitted signal must be one of these data types:

• 16-bit signed integers — Since the AD9361 RF chip has a 12-bit DAC, only the 12 most significant bits of the I and Q samples are used.

• Single-precision floating point — Complex values in the range of [–1, 1]. Since the AD9361/AD9364 RF chip has a 12-bit DAC, numbers of magnitude less than 0.0625 are lost.

• Double-precision floating point — Complex values in the range of [–1, 1]. Since the AD9361/AD9364 RF chip has a 12-bit DAC, numbers of magnitude less than 0.0625 are lost.

Data Types: int16 | single | double
Complex Number Support: Yes

Output Arguments

underflow — Data discontinuity flag

logical scalar

Data discontinuity flag, returned as a logical scalar.

• true indicates the presence of underflow resulting in noncontiguous data.

• false indicates no underflow.

You can use this value as a diagnostic tool to determine real-time execution of the object.

Data Types: logical

Object Functions

To use an object function, specify the System object as the first input argument. For example, to release system resources of a System object named obj, use this syntax:

release(obj)

Specific to comm.SDRTxE3xx

designCustomFilter	Design custom filter for Analog Devices AD9361 RF chip
info	Synchronize receiver or transmitter radio settings with radio hardware
transmitRepeat	Download waveform signal to radio and repeatedly transmit it over the air

Common to All System Objects

step	Run System object algorithm
isLocked	Determine if System object is in use
release	Release resources and allow changes to System object property values and input characteristics

Examples

Send Modulated Data to USRP E3xx Radio Hardware

Make sure your radio hardware is configured for host-radio communication by following the steps in Guided Host-Radio Hardware Setup.

Create a transmitter System object for your radio hardware with the specified properties. Use a single channel.

tx = sdrtx('E3xx', ...
    'IPAddress','192.168.3.2', ...
    'CenterFrequency',2.2e9, ...
    'BasebandSampleRate',800e3, ...
    'ChannelMapping',1)

tx = 
  comm.SDRTxE3xx with properties:

   Main
                DeviceName: 'E3xx'
                 IPAddress: '192.168.3.2'
           CenterFrequency: 2.2000e+09
                      Gain: -10
            ChannelMapping: 1
        BasebandSampleRate: 800000
    ShowAdvancedProperties: false

  Show all properties

Create a DPSK modulator System object.

mod = comm.DPSKModulator('BitInput',true);

Use modulated random data as the data source and transmit the data with the radio hardware.

for counter = 1:20
   data = randi([0 1],30,1);
   modSignal = mod(data);
   tx(modSignal);
end

## Establishing connection to hardware. This process can take several seconds.

Version History

Introduced in R2019b