MATLAB Examples

FM Monophonic Receiver Using Analog Devices AD9361/AD9364

This model shows how to use the Xilinx® Zynq-Based Radio Support Package with Simulink® to build an FM mono receiver. The receiver receives and demodulates the FM signal transmitted by the FM broadcast radio.

Refer to the Getting Started documentation for details on configuring your host computer to work with the Support Package for Xilinx® Zynq-Based Radio.

Contents

Introduction

Xilinx Zynq-Based SDR hardware along with Analog Devices™ AD9361/AD9364 is required for running the model. The model configures the SDR hardware to receive an FM signal over the air. The FM Mono receiver performs FM demodulation, deemphasis filter and rate conversion.

Setup

Before running the example, ensure you have performed the following steps:

Configure your host computer to work with the Support Package for Xilinx® Zynq-Based Radio. See Getting Started for help.

Structure of the Example

The top level structure of the FM Mono receiver model is shown in the figure below:

In this example, the radio baseband data is received from the SDR Hardware via a Zynq® SDR Receiver block ZC706 and FMCOMMS2/3/4 Receiver. The Zynq SDR receiver block is configured at a sampling rate of 960 kHz using the Baseband sample rate parameter in the Zynq SDR Receiver block. The deemphasis filter in the FM Receiver subsystem is set to 75 microseconds [ 1 ] and compensates for the preemphasis filter at the transmitter. The frequency response table is given below.

A resampler converts the sampling rate from 960 kHz to 48 kHz, a native sampling rate for the audio device. The resampling filter removes the 19 kHz stereo pilot tone.

Running the Example

The SDR hardware is configured to use input ports for the RF center frequency. Using input ports for these parameters allows them to be updated while the model is running. The center frequency can be configured to a local FM radio station using the Slider Gain block.

Set the center frequency to a local FM radio station and start the model. This tunes the SDR device to the local FM station and you can listen to the radio station through the audio device connected to your computer. Change the center frequency to listen to a different station.

Alternative Implementations

The example describes the Simulink model of a receiver for demodulating and processing an FM Mono signal transmitted by the FM broadcast radio. The example uses Zynq-based Hardware support package to build a monophonic FM receiver using SDR Hardware using Analog Devices AD9361/AD9364.

You can also view a MATLAB® implementation of the example in FM Monophonic Receiver Using Analog Devices AD9361/AD9364 using MATLAB

Troubleshooting the Example

If the received signal is very weak, you can try increasing the receiver gain by changing the Source of gain variable to Input port for the manual gain control mode or by changing it to 'AGC Fast Attack' or 'AGC Slow Attack'.

General tips for troubleshooting SDR hardware can be found in Xilinx Zynq-Based Radio Processing Errors and Fixes.

References