Day by day wireless users are increasing. So to increase the efficiency of system, we rely on Cognitive radio. It detects unused channel and sends the data through that channel. Here  multicarrier modulation techniques like Generalised Frequency Division Multiplexing and Universal Filtered Multicarrier play an important role as these techniques are non-orthogonal multicarrier schemes used for sending information with low latency and higher efficiency. In this paper,a technical review on both GFDM and UFMC candidate waveforms for 5G  has been given under wireless dispersive channels for cognitive radio. These use digital multicarrier transceiver concept which employs filters for pulse shaping so as to maintain control over transmitted signal’s spectral properties. The advanced LTE system provides standard compliant functions for design, simulation and verification of advanced communication systems. Cognitive radio is the intelligence that guides Software defined radio to choose the mode of operation and vital parameters mainly frequency, modulation, bandwidth and power. The main aim of opportunistic cognitive radio is the modification of said parameters depending upon the radio frequency environment, user situation and demands of network etc .