In this paper, a method for the design of nonlinear phase, full-band, ultra-wideband (UWB) pulses that satisfy the Federal Communications Commission's effective isotropic radiation power spectrum mask, or more generally, any other given mask, is introduced. The method uses convex programming in each step of the iterative procedure that updates the phase distribution of the goal function. Thanks to its mathematical structure, this method can be easily modified in order to be applied, in sequential fashion, to several different orthogonal UWB pulse-design problems, addressed later in the paper. The first among them is a problem considered in literature-design of multiple pulses, orthogonal when radiated. When employed for solving this problem, the method proposed here produces a considerably larger number of orthogonal pulses with high energy compared to the methods introduced before. As a novelty, the problem of designing pulses which are orthogonal in reception is considered. Then, a modification of our method is presented that can be used to solve this problem. We also introduce statistical criteria of robustness of pulses' orthogonality in reception, to the variation of the pulses' shape caused by the channel transfer function. After that, a modification of the proposed method is presented that is capable of producing a set of pulses with predefined maximum value of this criteria. Furthermore, it is shown that the method proposed can be used to efficiently design orthogonal pulses using a suboptimal value of the sample rate. All the concepts introduced are illustrated by design examples

We developed a positioning system using impulse radio UWB. The system consists of tags equipped only with transmitters and nodes provided with both transmitters and receivers. The system calculates the position of the tags using the TDOA method, whereby some nodes receive the UWB pulses sent from a tag. The tag is operated with a coin battery, and sends UWB pulses intermittently. The node sends the receiving time data to a PC via an Ethernet network for position calculation. We developed a time clock correction method, which is also required for the TDOA method. We will further evaluate positioning accuracy etc. in the future

Recently, Impulse Radio Ultra Wideband (IR-UWB) signaling has become popular for providing precise location accuracy for mobile and wireless sensor node localization in the indoor environment due to its large bandwidth and high time resolution while providing ultra-high transmission capacity. However, the Non-line-of-sight (NLOS) error mitigation has considerable importance in localization of wireless nodes. In order to mitigate NLOS errors in indoor localization this paper proposes and investigates a novel approach which creates a hybrid combination of channel impulse response (CIR)-based fingerprinting (FP) positioning and an iterative Time of Arrival (TOA) real time positioning method using Ultra Wideband (UWB) signaling. Besides, to reduce the calculation complexities in FP method, this paper also introduces a unique idea for the arrangement of reference nodes (or tags) to create a fingerprinting database. The simulation results confirm that the proposed hybrid method yields better positioning accuracies and is much more robust in NLOS error mitigation than TOA only and FP only and a conventional iterative positioning method.

IEEE 802.15 working group established a new study group, body area network (SG-BAN), to develop short range wireless communication technology in and around human body recently. Wearable healthcare is an important category of potential applications of BAN. This paper introduces the IEEE SG-BAN and investigates the performance of 802.15.4b and 802.15.4a for wearable healthcare applications in the heterogeneous networks environment. The object is better understanding of healthcare requirement of BAN and how and where BAN works to be started. In addition to the scalability issue, we found asymmetric clear channel assessment (CCA) abilities among different types of wireless technology. The asymmetric CCA has significant impact on system performance.