IF signal filtering techniques in low IF receiver for narrowband communications

This paper presents novel filtering techniques for interference cancellation using second order FIR notch filters in low IF receiver for narrowband communications. The presented technique employs several two classes of second order FIR notch filter to cancel the in-band interferences. In the presented filtering technique, IF signals are filtered by these filters, however, in general, the filtering for IF signals causes more power consumption. The interference cancellation filter is composed of not any multipliers but some registers and adders, therefore, it can be considered that the energy consumption for the cancellation can be reduced. Experimental results obtained from computational and actual measurements are shown to valid the effectiveness of the presented filtering technique.