Wireless Communications Systems Design with MATLAB and USRP Software-Defined Radios

Day 1 of 2

Communication over a Noiseless Channel

Objective: Modeling an ideal single-carrier communications system and becoming familiar with System objects.

• Sampling theorem and aliasing
• Using complex baseband versus real passband simulation
• Creating a random bit stream
• Discovering System objects and their benefits
• Modulating a bit stream using QPSK
• Applying pulse-shaping to the transmitted signal
• Using eye diagrams and spectral analysis
• Modeling a QPSK receiver for a noiseless channel
• Computing bit error rate

Noisy Channels, Channel Coding, and Error Rates

Objective: Modeling an AWGN channel. Using convolutional, LDPC, and turbo codes to reduce bit error rate. Error correcting codes from DVB-S.2 and LTE systems are used as examples. Accelerating simulations using multiple cores.

• Modeling an AWGN channel
• Using channel coding and decoding: convolutional, LDPC, and turbo codes
• Decoding using Trellis diagram and Viterbi algorithm
• Using Parallel Computing Toolbox to accelerate Monte Carlo simulations
• Discussion of alternative acceleration methods: GPUs, MATLAB Distributed Computing Server™, Cloud Center

Timing and Frequency Errors and Multipath Channels

Objective: Modeling frequency offset, timing jitter errors, and mitigation using frequency and timing synchronization techniques. Modeling flat fading, multipath channels, and mitigation using equalizers.

• Modeling phase and timing offsets
• Mitigating frequency offset using a PLL
• Mitigating timing jitter using Gardner timing synchronization
• Modeling flat fading channels
• Using training sequences for channel estimation
• Modeling frequency selective fading channels
• Using Viterbi equalizers for time-invariant channels and LMS linear equalizers for time-varying channels
• Demonstration of a real-time demodulation of single-carrier broadcast using RTL-SDR

Day 2 of 2

Multicarrier Communications Systems for Multipath Channels

Objective: Understanding motivation for multicarrier communications systems for frequency selective channels. Modeling an OFDM transceiver with a cyclic prefix and windowing. System parameter values from IEEE 802.11ac and LTE will be used.

• Motivation for multicarrier communications
• Introduction to Orthogonal Frequency Division Multiplexing (OFDM)
• OFDM symbol generation using the IFFT
• Inter-block interference prevention using a cyclic prefix
• Reduction of out-of-band emissions using windowing
• Advantages and disadvantages of OFDM
• Timing and frequency recovery methods for OFDM
• Channel estimation using pilot symbols
• Frequency domain equalization

Using Multiple Antennas for Robustness and Capacity Gains

Objective: Understanding alternative multiple antenna communications system. Modeling beamforming, diversity, and spatial multiplexing systems. Constructing a MIMO-OFDM system for wideband communications. MIMO modes of IEEE 802.11ac and LTE will be discussed.

• Advantages and types of multi-antenna systems
• Transmit and receive beamforming
• Receive diversity techniques
• Transmit diversity using orthogonal space-time block codes
• Narrowband multiple input-multiple output (MIMO) channel model
• MIMO channel estimation
• Spatial multiplexing using ZF and MMSE equalization
• Wideband communications using an MIMO-OFDM system

Building a Radio-in-the-Loop System

Objective: Understanding the radio-in-the-loop development workflow. Using RTL-SDRs and USRPs as radio-in-the-loop development platforms.

• Overview of the radio-in-the-loop workflow
• MathWorks communications hardware support (RTL-SDR, ADALM-PLUTO, USRP, Zynq^®-Based Radio)
• Hardware alternative comparison (pros/cons table)
• Different RIL transmit and receive modes (single burst, looped, streamed)
• Creation of an end-to-end single-antenna multicarrier communications system using a USRP
• Demonstration of a 2x2 OFDM-MIMO over-the-air system using USRPs