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Analytical studies of fragmented-spectrum multi-level OFDM-CDMA technique in cognitive radio networks

Akhoundi, F | 2016

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  1. Type of Document: Article
  2. DOI: 10.1109/UEMCON.2016.7777801
  3. Publisher: Institute of Electrical and Electronics Engineers Inc , 2016
  4. Abstract:
  5. In this paper, we present a multi-user resource allocation framework using fragmented-spectrum synchronous OFDM-CDMA modulation over a frequency-selective fading channel. In particular, given pre-existing communications in the spectrum where the system is operating, a channel sensing and estimation method is used to obtain information of subcarrier availability. Given this information, some real-valued multi-level orthogonal codes, which are orthogonal codes with values of {±1, ±2, ±3, ±4,...}, are provided for emerging new users, i.e., cognitive radio users. Additionally, we have obtained a closed form expression for bit error rate of cognitive radio receivers in terms of detection probability of primary users, CR users' sensing time and CR users' signal to noise ratio. Moreover, simulation results obtained in this paper indicate the precision with which the analytical results have been obtained in modeling the aforementioned system
  6. Keywords:
  7. Code-division multiple-access (CDMA) ; Multicarrier (MC) ; Orthogonal frequency division multiplexing (OFDM) ; Bit error rate ; Code division multiple access ; Codes (symbols) ; Fading (radio) ; Fading channels ; Frequency division multiplexing ; Frequency selective fading ; Mobile telecommunication systems ; Multiplexing ; Orthogonal frequency division multiplexing ; Signal receivers ; Signal to noise ratio ; Ubiquitous computing ; Analytical results ; Closed-form expression ; Cognitive radio network ; Detection probabilities ; Fragmented-spectrum ; Multi carrier ; Multi-user resource allocations ; Spectrum sensing ; Cognitive radio
  8. Source: 7th IEEE Annual Ubiquitous Computing, Electronics and Mobile Communication Conference, UEMCON 2016, 20 October 2016 through 22 October 2016 ; 2016 ; 9781509014965 (ISBN)
  9. URL: http://ieeexplore.ieee.org/document/7777801