  5G Cell Search (CS) is the first step for user equipment (UE) to initiate the
communication with the 5G node B (gNB) every time it is powered ON. In cellular
networks, CS is accomplished via synchronization signals (SS) broadcasted by
gNB. 5G 3rd generation partnership project (3GPP) specifications offer a
detailed discussion on the SS generation at gNB but a limited understanding of
their blind search, and detection is available. Unlike 4G, 5G SS may not be
transmitted at the center of carrier frequency and their frequency location is
unknown to UE. In this work, we demonstrate the 5G CS by designing 3GPP
compatible hardware realization of the physical layer (PHY) of the gNB
transmitter and UE receiver. The proposed SS detection explores a novel
down-sampling approach resulting in a significant reduction in complexity and
latency. Via detailed performance analysis, we analyze the functional
correctness, computational complexity, and latency of the proposed approach for
different word lengths, signal-to-noise ratio (SNR), and down-sampling factors.
We demonstrate the complete CS functionality on GNU Radio-based RFNoC framework
and USRP-FPGA platform. The 3GPP compatibility and demonstration on hardware
strengthen the commercial significance of the proposed work.
