ECE 463
Digital Communications Laboratory

Displaying course information from Spring 2012.

Section Type Times Days Location Instructor
AB1 LAB 1000 - 1250 W   251 Everitt Lab  Christopher Schmitz
AB2 LAB 1300 - 1550 W   249 Everitt Lab 
AB3 LAB 0900 - 1150 F   251 Everitt Lab 
AB4 LAB 1300 - 1550 F   251 Everitt Lab  Christopher Schmitz
AL LEC 0900 - 0950 W   251 Everitt Lab  Christopher Schmitz
Web Page http://courses.engr.illinois.edu/ece463/
Official Description Hands-on experience in the configuration and performance evaluation of digital communication systems employing both radio and optical signals. Course Information: Prerequisite: ECE 361 or ECE 459.
Subject Area Communications
Course Prerequisites Credit in ECE 459
Course Directors Steven J Franke
Detailed Description and Outline

Topics:

  • Spectrum Analyser tutorial, power spectral-density measurements
  • Baseband antipodal signaling
    • Observe and characterize envelope, spectrum, eye patterns
    • Bit-error-rate vs. Eb/No, clock timing error with matched filter
    • Bit-error-rate for sub-optimum filters
  • Coherent RF Communications - BPSK
    • Observe and characterize envelope, spectrum, eye patterns
    • Bit-error-rate vs. Eb/No, carrier phase error
  • Carrier synchronization using Costas loop for BPSK
    • Characterization of loop components:
      • VCO gain constant
      • phase detector gain constant
      • loop filter
    • Steady-state loop performance
    • Dynamic performance of carrier recovery loop-step response, loop transfer function
    • Effect of noise on loop performance
  • Noncoherent RF communications - DPSK
    • Observe and characterize envelope, spectrum, eye patterns
    • Measure bit-error-rate vs. Eb/No, delay error for delay and multiply detection
  • Clock timing recovery using PL
  • BPSK and DPSK performance in the presence of a CW jammer
  • Fiber-optic communications
    • Measurement of signal, noise power
    • Characteristics of noise
    • Observe and characterize eye patterns, bit-error-rate for high-speed optical link
Texts
Class notes.
Course Goals

The goals are to familiarize students with the techniques and instrumentation employed for measuring the performance and properties of digital communication systems and to provide hands-on experience with the components and sub-systems employed in a digital communication system.

Instructional Objectives

After Laboratory Exercise No. 4, the students should be able to do the following:

  • Understand the basic properties of maximal-length shift-register sequences. (a)
  • Understand the principles and practicality of implementing a self-synchronizing bit error detector for testing arbitrary digital communication systems. (a,b,c,k)
  • Design a test procedure and measure the bit energy and noise power spectral density in analog signals of a baseband communication system using both time-domain and frequency-domain measurement techniques. Use these values to compute Eb/No.
  • Design a procedure to generate the noise variance required per sample to achieve a desired Eb/No in digital signals. (a,b,c)
  • Analyze the performance of a baseband communication system that employs ideal Nyquist-based pulse shaping and matched filter responses in the presence of symbol-timing (clock) synchronization error. (a,b,c)
  • Analyze the performance of a practical implementation of a detector that employs non-Nyquist-based pulse shaping and/or non-matched filtering by accounting for intersymbol interference and timing errors. (a,b,c)
  • Design a test procedure and measure the bit-error probability in a baseband communication system as a function of Eb/No and as a function of clock-timing error. (a,b,c)
  • Design a test procedure and measure the bit-error performance in a BPSK communication system as a function of symbol-timing (clock) error, Eb/No and carrier-phase error. (a,b,c)
  • Characterize a low-noise amplifier (LNA) on the basis of noise figure, gain, and 1-dB compression point. (a,b,c,k)
  • Analyze a passband noise generator consisting of a room temperature resistor followed by a cascade of amplifiers and bandpass filters using the gain and noise figure values of each device. (a,b,c,k)

After Laboratory Exercise No. 7, the students should be able to perform all of the items listed under A plus the following:

  • Understand the operation of a Costas-loop for carrier phase synchronization in a passband communication system. (a)
  • Design a test procedure and measure the gain constants of phase detectors and voltage-controlled oscillators (and digitally-implemented numerically-controlled oscillators) employed in carrier-recovery loops. (a,b,c)
  • Predict the transient response and noise performance of a carrier recovery loop. (a)
  • Design a test procedure and measure the transient response and transfer function of a carrier-recovery loop using digital outputs from various test points within a numerically-controlled oscillator. (a,b,c)
  • Understand the principles of operation for a symbol-timing (clock) recovery loop. (a)
  • Apply their understanding of the carrier-recovery system to recover the channel bits of an over-the-air binary-FSK pager signal. (a,b,c,e,k)

After the final Laboratory Exercise, the students should be able to perform all of the tasks listed under A and B plus the following:

  • Work together to design, test, and construct a receiver for the digital transmission of an over-the-air (OTA) signal of their choosing, subdivide the project into tasks among themselves, construct and test the coded LabVIEW “subVIs,” and collectively report their working solution. Likely OTA signals include the Radio Broadcast Data System (RBDS) digital subcarrier of a local FM radio broadcast, digital radio, or unencrypted digital television. (a,b,c,d,e,g,k)
  • Design and analyze most common digital modulation schemes on the basis of spectral efficiency, power efficiency, and practical implementation. (a,b,c,e,k)
Last updated: 5/23/2013