Cebrail ÇİFLİKLİ, Ahmet Turgut TUNCER, Yusuf ÖZTÜRK

An OFDM throughput analysis for cognitive radio application in contiguous or noncontiguous TV white spaces

Radio frequency spectrum is a finite and scarce resource. Efficient use of the radio frequency spectrum is a fundamental research issue. Since a large portion of the assigned radio frequency spectrum is used only sporadically, the bands currently allocated to TV services can be opportunistically reassigned to support broadband networking services while continuing to provide broadcast TV. The fragmented and unused TV channels named white spaces have a considerable amount of bandwidth potential and long transmission ranges. Bandwidth scalability can be supported by bonding multiple contiguous or noncontiguous consecutive channels using orthogonal frequency division multiplexing (OFDM)-based cognitive radio. In this paper, an in-depth throughput analysis of OFDM fixed carrier spacing and fixed carrier number approaches has been done for various modulation schemes in TV white spaces. Signal propagation delay is studied under various channel conditions. An analytical model-based estimation of the throughput by taking into account channel bonding is presented.

Anahtar Kelimeler:

TV white space, channel bonding, fixed subcarrier spacing, fixed subcarrier number, 802.11af

An OFDM throughput analysis for cognitive radio application in contiguous or noncontiguous TV white spaces

Keywords:

TV white space, channel bonding, fixed subcarrier spacing, fixed subcarrier number, 802.11af,

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In this study, we presented an analysis and simulation framework to investigate the effect of FCN- or FCS-type OFDM technique on changing channel width in contiguous and noncontiguous TV bands.
Three scenarios for the FCN and FCS schemes were considered: 1) effect of modulation and coding scheme on throughput, 2) effect of propagation delay on throughput, 3) and bandwidth efficiencies while varying modulation schemes for 5, 10, and 20 MHz channel widths, respectively.
It is concluded that additional research should focus on improving the performance of OFDM systems that would be used in TV bands.
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