There is a worldwide trend towards the adoption of digital technology in communications and radio. In particular, terrestrial digital audio broadcasting (DAB) can provide higher quality audio than is currently available from existing Analog Modulation (AM) and Frequency Modulation (FM) services. In addition, digital broadcasting provides the opportunity to deliver auxiliary information such as traffic and weather information, or emergency alerts. In order to realize the potential of DAB in AM/FM bands, manufacturers and developers of radio broadcasting equipment, like Nautel of Halifax, NS, are supporting the global standard for In-Band On-Channel (IBOC) transmission proposed by iBiquity.

IBOC system is designed to deliver CD-quality DAB using existing spectral channels without interfering with continuing analog AM and FM broadcast. This provides a non-disruptive migration path from analog to digital services. In order to meet the needs of regulatory agencies and be able to reuse the current RF transmission equipment, the broadcasting equipment manufacturers must ensure the compatibility between the existing AM/FM and DAB signals through the proper adjustments of their power amplifiers. The mission of this research is to propose solutions and build prototypes that would enable the deployment of DAB using existing RF equipment, which constitutes major investment for broadcasters and manufacturers.

The general objective of this project is to show how to integrate the communication transceivers' analog radio frequency (RF) front-end and digital aspects of radio with the emerging software radio technology. The specific issues addressed are related to DAB with Nautel’s high power transmitters. The research novelty is in characterizing the performance tradeoffs of different modulation methods, transmitter linearity and spectrum utilization. To achieve the improved performance, investigations will be conducted to correct the signal before it passes through the RF stages. Practical implementations will be pursued using the DSP and Field Programmable Gate Arrays (FPGA) platforms.

The integrated RF-Digital Signal Processing (DSP) designs developed in this project will be applicable to any radio system with multilevel modulation schemes to increase transmission speeds and where there is a need to use non-linear amplifiers such as in satellite systems.

Dr. Jacek Ilow, Principal Investigator

Wireless Networking Research Group, Dalhousie University

An Application of Multi-wavelet Packets in Digital Communications
  M. You and J. Ilow
  CNSR 2004 Conference

Integrated RF/DSP Designs Using Software Radios: A Modern Approach to Radio Engineering
  Jacek Ilow
  CNSR 2003 Conference > full paper (pdf 544 KB)

Blind Compensation of Memoryless Nonlinear Effects in OFDM Transmissions Using CDF
  Congying Xia, Jacek Ilow
  CNSR 2003 Conference > full paper (pdf 167 KB)

Frequency Domain Equalization with Multiple Receiving Antennas for Single Carrier Signaling
  Zhan Zhang, Jacek Ilow
  CNSR 2003 Conference > full paper (pdf 472 KB)

[Last Revised: 2004 October 20]