Interference to DTTV reception by first adjacent channels

Planning for digital terrestrial television (DTTV) service in a crowded spectrum requires that power limits be placed on all adjacent channels, and in particular on first adjacent channels. Realistic power limits based on intermodulation products generated at the receiver by the desired and undesired signals are proposed. The proposed limits are a function of the fundamental power in the desired and undesired channels and the receiver\´s 3rd order Intercept Point (IP₃). The analysis shows that in many markets present Desired/Undesired (D/U) ratios underestimate the expected interference from strong signals, and that the receiver\´s IP₃ should be at least 16 dBm for the dynamic range expected in the U.S. Additional improvement can be attained by minimizing the sideband splatter generated by the transmitter of the first adjacent channel and by designing a "smart" front-end receiver.