Secondary Spectrum Access with LT Codes for Delay-Constrained Applications
Harikeshwar Kushwaha, R. Chandramouli · 2007
With the advent of cognitive radios, secondary usage of spectrum on opportunistic basis, in the licensed band, is becoming practical. In this type of opportunistic spectrum access, secondary users may loose access due to the sudden arrival of a primary user who owns the spectrum. In order to ensure the link reliability and to compensate for the loss, some spectrally efficient mechanisms are required. In this paper we consider the spectrum pooling model for secondary spectrum access for delay-constrained applications. Along with this we study the application of Luby Transform (LT) codes to compensate the secondary user for the loss incurred due to primary user interference. We study the trade-offs between spectral efficiency, link reliability and overhead due to LT coding. Primary user traffic model is used to parametrize the trade- offs. Simulation results are presented for the secondary spectrum access model.