OFDM Modulation Using MATLAB

Orthogonal Frequency Division Multiplexing (OFDM) is the multicarrier digital modulation technique used by modern wireless communications systems such as 5G and LTE cellular, and WiFi. The advantages of OFDM over other techniques, such as single carrier QAM, include support of higher data rates with a simpler receiver design. Specifically, the use of OFDM with a cyclic prefix (CP) enables fast Fourier transform based (FFT-based) equalization and synchronization, which simplifies the reception as compared to techniques used to receive comparable data rates in single carrier QAM. For a conceptual explanation of OFDM, see What Is OFDM? - MATLAB & Simulink. This set of examples uses the fft and ifft functions to demonstrate transmission and reception of OFDM signals.

• Introduction to OFDM

• Basic OFDM with No Cyclic Prefix

• Equalization, Convolution, and Cyclic Prefix Addition

• OFDM and Equalization with Prepended Cyclic Prefix

• OFDM with FFT Based Oversampling

Communications Toolbox™ and the wireless standards-based toolboxes provide customized OFDM functions and examples that support generating basic OFDM systems and OFDM systems compliant with those standards-based protocols.

• Communications Toolbox includes the ofdmmod and ofdmdemod functions to provide general OFDM functionality, such as CP addition, and null and pilot subcarrier insertion. The comm.OFDMModulator and comm.OFDMDemodulator System objects also enable applying windowing to OFDM transmissions.

• 5G Toolbox™ includes the nrOFDMModulate (5G Toolbox) and nrOFDMDemodulate (5G Toolbox) functions to work with 5G OFDM waveforms.

• LTE Toolbox™ includes the lteOFDMModulate (LTE Toolbox) and lteOFDMDemodulate (LTE Toolbox) functions to work with LTE OFDM waveforms.

• WLAN Toolbox™ includes the wlanWaveformGenerator (WLAN Toolbox) function to generate WLAN OFDM waveforms.

• The Wireless Waveform Generator app offers a convenient interface to configure and generate basic OFDM waveforms and OFDM waveforms adhering to these standards. The app also enables you to output the associated OFDM waveform generation code to use in your simulation.

For a sampling of examples that use OFDM features in the wireless toolbox products, see:

• NR PDSCH Throughput (5G Toolbox)

• Simulate Propagation Channels (LTE Toolbox)

• 802.11 Dynamic Rate Control Simulation (WLAN Toolbox)