This paper focuses on efficient utilization of spectrum bandwidth to improve throughput in wireless adhoc networks. As the frequency spectrum is a limited resource for wireless communications and as per the next generation requirements the frequency spectrum becomes a scarce resource, and consequently, its efficient use is of the ultimate importance. To meet with the growing demand, network design focused on increasing the spectral efficiency by making use of advancement in Cognitive Radio technology. Cognitive Radio can reduce the spectrum shortage problem by enabling unlicensed users equipped with Cognitive Radios to reuse and share the licensed spectrum bands. in this paper our work aims the comparing the techniques used for enhancing the throughput in CR.