This paper exhibits a methodology to achieve a system level design for Cognitive Radio (CR) receiver supporting IEEE 802.22 Standard. Based on superheterodyne receiver supporting Sub-Band Sensing, the overall radio system characteristics depicted from the IEEE 802.22 Standard specifications are dispatched through the different receiver blocks. Moreover, we developed the theoretical calculation and different techniques of system level design. Each of Radio Frequency (RF) characteristics such as noise figure (NF), gain and linearity (third order intercept point, (IIP3)) is simulated taking in account the analog-to-digital converter (ADC) full scale power constraint. On the one hand, our system level simulation results proved that the receiver architecture is capable to perform spectrum sensing and to allow communication processing. The receiver performs a total gain of 51 dB and an IIP3 of -19.8 dBm for low gain mode. It achieves 105 dB as gain and 9.9 dB for noise figure for high gain mode.