E3xx Receiver

Receive data from USRP® E3xx radio hardware

  • Library:
  • Communications Toolbox Support Package for USRP Embedded Series Radio / E3xx

Description

The E3xx Receiver block receives data from a USRP®[1] E3xx radio hardware.

The block supports these radio hardware devices:

  • USRP® E310

  • USRP® E312

You can use the E3xx Receiver block to simulate and develop various software-defined radio (SDR) applications. This diagram shows the conceptual overview of transmitting and receiving radio signals in Simulink® using the Communications Toolbox™ Support Package for USRP® Embedded Series Radio. Simulink interacts with the E3xx Receiver block to receive signals from the radio hardware.

Ports

Input

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

Dependencies

To enable this port, set the Source of center frequency parameter to Input port.

Data Types: double

External gain, specified as a numeric scalar or a 1-by-2 numeric vector. The valid gain range is from –10 dB to 73 dB and depends on the center frequency. An incompatible gain and center frequency combination returns an error from the radio hardware.

Set the gain based on the Channel mapping parameter configuration.

  • 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 block 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 Channel mapping parameter.

Dependencies

To enable this port, set the Source of gain parameter to Input port.

Data Types: double

Output

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Output signal received from the radio hardware, returned as a complex matrix. The number of columns in the matrix depends on the number of channels in use, as specified by the Channel mapping parameter. Each column corresponds to a channel of complex data received on one channel.

This port supports complex values with these data types:

  • 16-bit signed integers — Complex values are the raw 16-bit I and Q samples from the board. The 12-bit value from the ADC of the AD9361 RF chip is sign-extended to 16 bits.

  • Single-precision floating point — Complex values are scaled to the range of [–0.0625, 0.0625]. The block derives this value from the sign-extended 16 bits received from the board.

  • Double-precision floating point — Complex values are scaled to the range of [–0.0625, 0.0625]. The block derives this value from the sign-extended 16 bits received from the board.

To specify the data type, use the Output data type parameter.

To qualify data reception, use the data valid port. The first valid data frame can contain transient values, resulting in packets containing undefined data.

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

Valid data indicator, returned as one of these values:

  • 1 indicates that the block has received data from the radio hardware.

  • 0 indicates that the block has not received data from the radio hardware.

Dependencies

To enable this port, on the Advanced tab, update Data timeout (sec) to a value other than Inf.

Data Types: Boolean

Data discontinuity flag, returned as one of these values:

  • 1 indicates the presence of overflow resulting in noncontiguous data.

  • 0 indicates no overflow.

You can use this port as a diagnostic tool to determine real-time operation of the E3xx Receiver block. If your model is not running in real time, increase the frame size to approach or achieve real-time performance. Alternatively, you can decrease the baseband sampling rate.

Dependencies

To enable this port, on the Main tab, select the Enable output port for overflow indicator parameter.

Data Types: Boolean

Parameters

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The E3xx Receiver block supports up to two channels to receive data from the E3xx radio hardware. Use the Channel mapping parameter to indicate whether to use a single channel or two channels. For each channel in the output signal, data, you can set the Gain (dB) parameter independently, or you can apply the same setting to all channels. All other parameter values are applied to each channel in use.

To check connectivity between the block and the radio hardware, and to synchronize radio settings between them, on the Main tab, click Info.

When you set block parameter values, the E3xx Receiver block first checks that the values have the correct data types. If the values pass those checks, the values can still be out of range for the radio hardware. In that case, the radio hardware sets the actual value as close to the specified value as possible. When you next synchronize the block with the radio hardware by clicking Info, a dialog box displays the actual values.

If a parameter is listed as tunable, then you can change its value during simulation.

Main Tab

IP address of the radio hardware, specified as a dotted-quad expression.

This parameter 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 Radio IP address accordingly.

Source of center frequency, specified as one of these options:

  • Dialog — Set the center frequency by using the Center frequency (Hz) parameter.

  • Input port — Set the center frequency by using the center frequency input port.

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

Tunable: Yes

Dependencies

To enable this parameter, set the Source of center frequency parameter to Dialog.

Data Types: double

  • AGC Slow Attack — For signals with slowly changing power levels.

  • AGC Fast Attack — For signals with rapidly changing power levels.

  • Dialog — Specify the gain by using the Gain (dB) parameter.

  • Input port — Specify the gain by using the gain input port.

Gain in dB, specified as a numeric scalar or a 1-by-2 numeric vector. The valid gain range is from –10 dB to 73 dB and depends on the center frequency. An incompatible gain and center frequency combination returns an error from the radio hardware.

Set the gain value based on the Channel mapping parameter configuration.

  • 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 block 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 Channel mapping parameter.

Tunable: Yes

Dependencies

To enable this parameter, set the Source of gain parameter to Dialog.

Data Types: double

Channel output mapping, specified as a scalar or a 1-by-2 vector:

  • 1 — Only channel 1 is in use.

  • 2 — Only channel 2 is in use.

  • [1 2] — Both channels are in use.

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

Note

To synchronize the block with the radio hardware, on the Menu tab, click Info. 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

Select output data type, as one of these options:

  • int16 — Integer values are the raw 16-bit I and Q samples from the board. The 12-bit value from the ADC of the AD9361 RF chip is sign-extended to 16 bits.

  • single — Single-precision floating point values are scaled to the range of [–0.0625, 0.0625]. The block derives this value from the sign-extended 16 bits received from the board.

  • double — Double-precision floating point values are scaled to the range of [–0.0625, 0.0625]. The block derives this value from the sign-extended 16 bits received from the board.

Number of samples per frame, specified as a positive integer. In single-channel mode, the number of samples per frame must be even. When streaming to the host, using large frame sizes can give more efficient performance. To determine real-time operation of the object, use the overflow output port.

Select this parameter to enable the overflow output port during host-radio hardware data transfers.

When you select this parameter, the block produces a set of contiguous frames. This setting can help simulate models that cannot run in real time. When you enable burst mode, specify the amount of contiguous data by using the Frames in burst parameter. For more information on how to use this parameter, see Burst Mode.

Number of frames in a contiguous burst, specified as a positive integer.

Dependencies

To enable this parameter, select the Enable burst mode parameter.

Data Types: double

Filter Tab

When you select this parameter, the filter chain uses a custom filter design instead of the default filter design. If the E3xx Receiver block does not have a custom filter design applied yet, click on Launch filter wizard to open the ADI filter wizard. The wizard enables you to design a custom filter for the Analog Devices® AD9361 RF chip based on the Baseband sample rate (Hz) parameter. You can adjust and optimize the settings for calculating the analog filters, interpolation and decimation filters, and FIR coefficients. When you finish with the wizard, to apply the custom filter design to the block, click Apply on the block mask.

Note

When applying a custom filter to the E3xx Receiver block by using the ADI filter wizard, Use custom filter is automatically selected. To switch between the default and your custom filter design, clear or select Use custom filter, respectively. Then click Apply on the block mask.

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

Advanced Tab

Select this parameter to enable the radio hardware data path to bypass 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.

When you select this parameter, the block applies in-phase and quadrature (IQ) imbalance compensation.

When you select this parameter, the block applies an RF direct current (DC) blocking filter.

When you select this parameter, the block applies a baseband DC blocking filter.

When you select this parameter, you can change the sample time of the block, by using the Sample time parameter. For more information, see SDR Receiver Sample Times.

Sample time of the block, specified as a positive scalar. The default value corresponds to Samples per frame divided by Baseband sample rate (Hz). Consider changing the default value only when deploying a hardware-software co-design implementation.

Dependencies

To enable this parameter, select the Override automatic sample time parameter.

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

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

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

Data Types: double

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.

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

  • Disabled — Disable BIST signal injection.

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

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

When you enable BIST signal injection, you can set the source of BIST signal generation with the Signal generator mode parameter.

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 Tone frequency (Hz) and Tone level (dB) parameters, respectively.

Dependencies

To enable this parameter, set the Test signal injection parameter to Tone Inject Tx or Tone Inject Rx.

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

Dependencies

To enable this parameter, set the Signal generator mode parameter to Tone.

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

Dependencies

To enable this parameter, set the Signal generator mode parameter to Tone.

Introduced in R2019b


[1] USRP, USRP2, UHD, and Ettus Research are trademarks of National Instruments Corp.