Doppler Spectrum of Wireless Channels

2. Regarding the Doppler spectrum of wireless channels, please answer the following questions: (1) In certain wireless channels, Doppler frequency shift can cause aliasing in the output signal. Describe the various causes of aliasing; (2) There exists a classic spectrum in wireless channel Doppler spectra. Explain the mechanism behind this spectral shape; (3) Write code using Simulink tools (via S-Function approach) to generate a single-path Rayleigh channel with a classic Doppler spectrum shape, where the mobile speed is 120 km/h. Additionally, answer: Possible methods to verify the correctness of the computer-generated classic spectrum.

Doppler Shift Causes Aliasing in Wireless Channel Output Signals

(1) In certain wireless channels, Doppler shift can cause aliasing in the output signals. This document analyzes various causes of aliasing and explains the mechanism behind the classic Doppler spectrum. (2) The implementation details include creating a single-path Rayleigh channel with Simulink using S-Function, configured for 120 km/h velocity with classic Doppler spectrum. (3) Validation methods using spectral analysis tools and theoretical comparisons are discussed to verify the generated spectrum's correctness.

SIMULINK Implementation of DDS Simulation Model with Constant Control Word

Implementing a DDS simulation model using MATLAB's SIMULINK tool with constant control word parameters for frequency synthesis analysis

Chirp Signal Pulse Train Implementation Using Simulink Tool

File specifications: 1) mychirpmdl.mdl implements a chirp signal pulse train using Simulink tool. Parameter configurations can be referenced from MATLAB help documentation. 2) mychirp.m is a MATLAB source file implementing chirp signal pulse train with detailed comments and configurable parameters (note parameter interdependencies). 3) mychirp.fig displays the execution results of mychirp.m. 4) mypluse.m demonstrates function-based pulse train implementation for reference only (not used in actual design).