Development of Energy Efficient Cognitive Radio Network using Sequential Quadratic Programming

For secondary users in CDMA-based cognitive radio networks, the power allocation issue is examined through a two-phase protocol that includes spectrum sensing and data transmission. In the first phase, availability of frequency band is detected using cooperative spectrum sensing. Thereafter, in the second phase, secondary users transmit the data using CDMA scheme if the band is estimated to be free. The sensing discussion parameters and transmit energy have been optimized jointly using sequential quadratic programming method to reduce the total average energy consumption per time slot. The detection probability and secondary users' quality of service are taken into consideration during optimization. Simulation results show that SQP method leads to more energy saving as compared to copolyblock algorithm for lower sensing SNRs and higher data rate. It has also been shown that MAJORITY rule results in more energy saving than OR rule.