This paper discusses some of the issues associated with broadband wireless access particularly directed at the non Line-of-Sight (nLoS) paths necessary for large scale deployment of Point to Multipoint networks. The paper discusses the modulation choices that can be made and how they affect the deployability of the systems. The author recommends the use of Orthogonal Frequency Division Multiple...

The paper presents ultra wideband (UWB) channel measurements from 3.1 to 8.0 GHz in office and lecture hall environments carried out at the premises of University of Oulu. Both line-of-sight (LOS) and non-LOS (NLOS) channels were measured having transmitter-receiver separation from 4 to 10 m. Channel parameters that are corresponding to the modified IEEE 802.15.3a model are extracted from the m...

Mobile location techniques in wireless communication networks have received significant attention in recent years. One of the main problems impeding accurate location estimation is non-line-of-sight (NLOS) propagation. In this paper, we propose a novel method by incorporating constrained optimization algorithm with an equalization scheme, where the weights are derived from root mean square dela...

Wireless location is the function used to determine the mobile station (MS) location in a wireless cellular communications system. When it is very hard for the surrounding base stations (BSs) to detect a MS or the measurements contain large errors in non-line-of-sight (NLOS) environments, then one need to integrate all available heterogeneous measurements to increase the location accuracy. In t...

This paper presents an analysis of the localization accuracy of indoor positioning systems using Cramer’s rule via IEEE 802.15.4 wireless sensor networks. The objective is to study the impact of the methods used to convert the received signal strength into the distance that is used to compute the object location in the wireless indoor positioning system. Various methods were tested and the loca...

SUMMARY Sensor networks, in which many small terminals are wire-lessly connected, have recently received considerable interest according to the development of wireless technology and electronic circuit. To provide advanced applications and services by the sensor networks, data collection including node location is essential. Hence the location estimation is important and many localization schem...

The susceptibility of millimeter waveform propagation to blockages may largely restrict the coverage of mmWave signals. To overcome blockages, we propose to leverage two-hop device-to-device (D2D) relaying. Using stochastic geometry, we derive expressions for the downlink coverage probability of a relay-assisted mmWave cellular network when the D2D links (from relays to destinations) are implem...

The measurement results of the wideband wireless multiple-input multiple-output (MIMO) channels in outdoor environments are presented. Our wideband wireless MIMO channel sounder consists of four transmitters and eight receivers, and operates at a carrier frequency of 1.8 GHz with a bandwidth of 2.5 MHz. After obtaining the multipath delay profiles from the data collected in non-line-of-sight (N...

In this paper, we propose a new low-complexity joint estimator of the mean angle of arrival (AoA), the angular spread (AS), and the maximum Doppler spread (DS) for single-input multiple-output (SIMO) wireless channel configurations in a macrocell environment. The non-line-of-sight (NLOS) case is considered. The space-time correlation matrix is used to jointly estimate the three parameters. Clos...

In this paper, the simulator for LED communication channel in indoor was studied. Indoor circumstance was supposed that the shape was hexahedron type and LEDs were located on the ceiling and receiver could be located anywhere. Simulator UI was designed so that upper considered parameters could be easily set. Channel characteristics was composed of LOS(Line Of Sight) and NLOS(Non LOS) LED signal...