b'Orthogonal Frequency-divisionAdvancing technology that enables the Internet of Things applications, such as Multiplexing-compatiblesmart grid, smart home/city, and sensor networks.Underlay CommunicationC yclic prefixed direct sequence spread spectrum (CP-DSSS) signaling was used as a data channel for passing a small amount of information Channel for Massive Machine- between devices in an underlay mode while avoiding any significant type Communications in Fifthinterference to mobile broad band communications. CP-DSSS enables a parallel network to the Long Term Evolution (LTE) network for the new massive machine Generation and Beyond type communication applications. The LTE network and the proposed network of devices will co-exist over the same spectral resources with a minimum amount of interference among them. Compared to competing technologies, CP-DSSS allows for communications in the low signal to noise ratio regime. It can be spectrally isolated from primary users and the waveform can trivially carry out low-complexity multi-user and multi-antenna communications. All these properties are key in establishing TOTAL APPROVED AMOUNT:CP-DSSS as an underlay femtocell network technology that can co-exist with 5G and $789,095 over 3 years beyond primary network communications in both time and frequency.PROJECT NUMBER:The CP-DSSS capacity was compared to the ubiquitous orthogonal frequency-19A39-137 division multiplexing technology, where it was shown that CP-DSSS achieves the PRINCIPAL INVESTIGATOR:same capacity as orthogonal frequency-division multiplexing. The unique signaling Arslan Majid of CP-DSSS offers a simple symbol rate reduction technique that greatly reduces CP-DSSS transceiver complexity at low signal to noise ratios when compared to CO-INVESTIGATORS: orthogonal frequency-division multiplexing. This important finding distinguishes Hussein Moradi, INL CP-DSSS for low-powered operation. In addition, it establishes CP-DSSS as a suitable Behrouz Farhang-Boroujeny,underlay technology for femtocell network communications which share the same University of Utah spectrum as the primary network.One goal of this research was to identify an optimal or near-optimal detector for the waveform. The usefulness of such a detector allows the waveform to establish links that approach channel capacity. It was found that a combination of match-filter detection and time-reversal precoding are sufficient for symbol detection. A frequency-domain multi-user detector design using a regularized zero-forcing precoder was proposed to further reduce the computational cost in both the uplink and downlink communications. Critical to the design of this precoder was devising a mechanism to reuse the large matrix inverses necessary for carrying out the calculations involved in transceiver precoding and detection.Illustration of a CP-DSSS based femtocell network that synchronizes with 5G and beyond primary base station (BS) networks and establishes a secondary network of CP-DSSS communications.120'