UCLA Extension

Multirate Signal Processing in Transmitter and Receiver Designs


Digital Signal Processing (DSP) has become the enabling technology for the signal-conditioning and signal-processing tasks performed in modern modulators and demodulators. These tasks include spectral shaping, matched filtering, narrow-band and base-band filtering, sample rate changes (interpolation and decimation), timing acquisition, carrier acquisition, automatic gain control, I-Q balancing, DC-canceling, channel equalization, spectral translation, direct digital synthesis of local oscillator, and sigma-delta requantization. In first- and second-generation implementations of DSP-based modems, the architecture and signal-flow have been virtual carbon copies of equivalent analog prototype designs. Next generation implementations have a significantly different structure, reflecting a more mature understanding of the capabilities of multirate DSP algorithms in which the sampling clock becomes a powerful processing tool.

This course presents the structure, unique attributes and capabilities, and implementation considerations of standard multirate filter structures including polyphase, dyadic half-band, and Cascade Integrator-Comb (CIC). The course also reviews the functional tasks of modulators and demodulators, and identifies where and how multirate signal processing can be inserted in the signal flow paths to improve performance, enhance capabilities, and reduce cost of system implementation.

Course Materials

The text, Multirate Signal Processing for Communication Systems, fredric j. harris (Prentice Hall, 2004), and lecture notes are distributed on the first day of the course. The notes are for participants only and are not for sale.

Coordinator and Lecturer

fredric j. harris, PhD, Cubic Signal Processing Chair Professor of Electrical and Computer Engineering, San Diego State University, California. Professor harris is a recognized expert in the field of Digital Signal Processing (DSP), especially as applied to Modem Design, radio surveillance, satellite communications, radar, sonar, acoustic monitoring equipment, and laboratory instrumentation. He is the author of the text, Multirate Signal Processing for Communication Systems. Since 1970, he has been a consultant to such organizations as the U.S. Navy Ocean Systems Center, Lockheed, ESL, Cubic, Hughes, BAE, Scientific Atlanta, Rockwell, Northrop Grumman, Boeing, and Inritsu. He also has presented courses on Modem Design, Multirate Signal Processing, DSP Based Synchronization, DSP for Communication Systems, OFDM, and Spectrum Analysis, Dr. harris has conducted seminars in DSP for Motorola, Qualcomm, Northrop Grumman, BAE, Lockheed, Raytheon, NRL, and SPAWAR.

Course Program

Practical Design of Finite Impulse Response Filters

  • Spectral and time domain characteristics
  • Transition bandwidth
  • Side-lobe levels and spectral envelope
  • In-band ripple level and paired echoes
  • Remez Algorithm revisited

The Resampling Process

  • The Nobel Identity
  • I-F sampling
  • Nyquist zone filtering
  • Intentional aliasing and spectral translation

Multirate FIR Filters

  • Decimators (down-sampling)
  • Interpolators (up-sampling)

Polyphase Partitions

  • Base-band filtering
  • Multi-channel filtering
  • Cascade filters

Half Band Filters

  • Quadrature mirror filters
  • Hilbert transform filters

Cascade Integrator-Comb Filters

  • Hoegenauer filter structures

Recursive Multirate Filters

  • Polyphase all-pass structures
  • Base-band filtering
  • Multi-channel filtering
  • Cascade filters

Recursive Half Band Filters

  • Quadrature mirror filters
  • Hilbert transform filters

MODEM Applications

  • Shaping filters with up-sampling
  • Shaping filters with Nyquist zone spectral translation
  • Cascade shaping filters for arbitrary re-sampling and spectral translation
  • Matched filters with up-sampling for timing recovery
  • Multi-channel modulation and demodulation
  • Narrow-band signal and noise generators
  • PM, QAM, and FM modulators and signal generators
  • VSB modulators
  • Simulation considerations
  • Direct digital synthesizers
  • CORDIC structures in modulators and demodulators
  • Re-sampling for ADC and DAC applications
  • Multirate considerations in equalizer filters


For more information contact the Short Course Program Office:
shortcourses@uclaextension.edu | (310) 825-3344 | fax (310) 206-2815