Narrow Band Digital Filtering Approach for CR-IoT Node with Carrier Aggregation Using Zero/Pole Placement

Abstract

Using zero/pole design method, the proposed narrow band (NB) infinite impulse response band-pass filter (IIR-BPF) can be designed for coarse narrow spectrum sensing (NSS) algorithms with carrier aggregation (CA) capability to be employed in cognitive radio internet-of-things (CR-IoT) nodes. This IIR-BPF can extract the targeted physical radio resource blocks (PRBs) in the wide orthogonal frequency division multiplexing (OFDM) aggregated bandwidth prior of performing the sensing process. The practical frequency response characteristics of the filter are addressed. The use of the suggested digital filter with energy detector (ED) shows sensing performance enhancement presented by probability or error reduction under noise power uncertainty and low signal-to-noise ratio (SNR). For instance, at SNR=-13 dB and for the same sample complexity (N=100), the probability of error is reduced from 0.67 to 0.48 using the proposed solution.