OPTIMIZING JOINT POWER AND CHANNEL ALLOCATION WITH QOS CONSTRAINTS IN MULTI-USER OFDM COGNITIVE RADIO SYSTEMS

With the help of orthogonal frequency division multiplexing (OFDM) and quality-of-service (QoS) requirements like signal-to-interference-plus-noise ratio (SINR) and proportional rate constraints, we look at the combined power & channel allocation issue for multi-user cognitive radio systems in this proposed system. Power and channel allocation problems get more difficult because to the QoS requirements for each cognitive radio user required by their minimal SINR and interference brought about by secondary unlicensed users to prime users. A developing idea for effective RF spectrum usage is opportunistic spectrum access employing cognitive radio technology, which enables unlicensed secondary users to access the licenced spectrum without negatively affecting the licenced main users.We give a formal analysis for a suggested technique and use numerical simulation results to explain the concept. In this study, combined channel and power allocation for dynamic spectrum access in an OFDM-based cognitive radio network is taken into consideration. Secondary users are obliged to adhere to prescribed requirements for minimum SINR, transmit power, proportional rate, and interference limit limitations. With the exception of two requirements—interference limitations and minimal SINR constraints—the issue under consideration in this work is quite similar to the problem.It should be noted that in OFDM-based cognitive radio systems, channel allocation is carried out based on maximal SINR to achieve high attainable rates, which causes severe interference to main users. As a result, we jointly take into account the channel's SINR and the interference caused by secondary users as constraints in the optimisation issue and offered a solution.