Using Convolutional Codes in Underlay Cognitive Radios: Performances and BER Bounds

In this paper, bit error rate (BER) of the secondarycognitive system is studied using three different receivers: I) softViterbi decoder only, II) optimal MMSE detector only and III)combining soft Viterbi decoder and MMSE detector. The resultsshow that the combined optimal MMSE detector and soft Viterbidecoder in the cognitive receiver removes the effects of the stronginterference substantially at the low signal-to-noise ratio (SNR)region.

Keywords:

Cognitive radio system , optimal estimator , secondary user , primary user , interference , bit error rate