2nd International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications

Research Article

Spectrum Occupancy Estimation in Wireless Channels with Asymmetric Transmitter Powers

  • @INPROCEEDINGS{10.1109/CROWNCOM.2007.4549804,
        author={John T. MacDonald and Dennis A. Roberson},
        title={Spectrum Occupancy Estimation in Wireless Channels with Asymmetric Transmitter Powers},
        proceedings={2nd International ICST Conference on Cognitive Radio Oriented Wireless Networks and Communications},
        publisher={IEEE},
        proceedings_a={CROWNCOM},
        year={2008},
        month={6},
        keywords={Artificial satellites  Base stations  Cognitive radio  Interference  Radar detection  Radio frequency  Radio transmitters  Receivers  Satellite broadcasting  Spaceborne radar},
        doi={10.1109/CROWNCOM.2007.4549804}
    }
    
  • John T. MacDonald
    Dennis A. Roberson
    Year: 2008
    Spectrum Occupancy Estimation in Wireless Channels with Asymmetric Transmitter Powers
    CROWNCOM
    IEEE
    DOI: 10.1109/CROWNCOM.2007.4549804
John T. MacDonald1, Dennis A. Roberson2
  • 1: Sapient Systems, Inc. Suite 34 456 West Frontage Road Northfield, IL 60093
  • 2: Department of Computer Science Illinois Institute of Technology Chicago, IL 60616

Abstract

In proposed cognitive radio schemes, channel occupancy is often offered as the metric to determine if a channel is free to open a new communication channel. Channel occupancy is the time average of detected transmissions above a certain power level. In many systems the transmission power between the uplink side and down-link side are asymmetric. If a single power threshold is used, then a system may underestimate channel occupancy on the low power down-link side. This results in an increased probability of interference in an existing channel if a listen-before-talking scheme is used. To avoid this hidden terminal problem, cognitive radios need to better understand the receiver properties of existing wireless channels.