The demand for communication bandwidth has sharply increased in recent years as a result of a dramatic rise in wireless communication systems. As we enter this new era of wireless networks, traditional methods of spectrum use based on fixed and static allocation are no longer sufficient to meet the corresponding demand for wireless spectrum. It is critical to create new inventive forms that allow for the dynamic assignment of spectrum space based on requirements. Cognitive radio (CR) networks are created to circumvent the radio spectrum’s static assignment policy’s utilization restriction. Additionally, NOMA is a newly discovered multiple spectrum access approach that makes use of successive interference cancellation (SIC) at the receiver and superposition coding (SC) at the transmitter to permit simultaneous communication between several users on the same frequency, space, and time. The main problem of CR is spectrum sensing, which determines whether a spectrum band is in use and allows a CR to start a transmission if the band is free.The Vertical Bell Laboratories Layered Space-Time (V-BLAST) receiver is based on energy detection for the CR-NOMA system used in this thesis work. The detection process is to receive the superimposed signal,order based on the signal-to-noise ratio (SNR), decode using the minimum mean square error (MMSE), and then cooperate using the maximum ratio combining (MRC) scheme to determine the channel status. The simulation result shows the probability of detection is improved with the number of sensing antenna where as decreased the probability of missed detection and probability of false alarm. Further The V-BLAST detector is high in terms of diversity order used to increase the received instantaneous SNR. Thus, using CR-NOMA based V-BLAST types of system is best to improve the detection probability. Key Words: CR, NOMA, Spectrum Sensing, V-BLAST