This article proposes an Internet of Things (IoT) wide-area communication system concept deployed within the operator?s licensed macrocellular band, suitable for low-energy, low-complexity IoT modules with low-priority and infrequent IoT traffic. This article also proposes a simplified air interface protocol for IoT and a simultaneous access channel for uplink (UL) IoT communication. The proposed system concept can be considered either as an enhancement or as an overlay to the existing cellular systems.

Existing cellular wireless systems operate with a predominantly network controlled, connection oriented frame based protocol architecture. A User Terminal (UT) is required to signal the network frequently to maintain its connectivity, and makes requests for uplink bandwidth to transmit packets. In such systems, for emerging applications, such as machine-to-machine (M2M), where small packets are transmitted sporadically, the bandwidth required for signaling is much more than the actual bandwidth to transmit the data. In this paper, we propose a novel connectionless uplink simultaneous access technique without the need of strict synchronization. UTs pick an uplink (UL) resource which is advertised by the network as a common radio resource for small packet transmissions, and transmit the data packets. The data packet includes a preamble sequence and network assigned identity. The transmitted packets from each UT may not be in perfect synchronization with the UL system timing. The base station (BS) uses a novel multi-user detection technique to separate these transmissions. Simulation results of the proposed method for an OFDM based system are shown be promising.

This paper presents a closed-loop control system for tuning the antenna matching network using power measurements in the transmit mode. Three methods are proposed as the basis of the control system to improve the efficiency of signal transmission via adaptively adjusting the scattering parameters of the matching network in real-time. The proposed adaptive match system is analyzed thoroughly using an in-house prototype comprising a parallel-LC network with two tunable capacitors. Detailed complexity analyses of the proposed methods are also presented.