One of the challenging problems in collaborative position localization arises when the distance measurements contain Non-Line-Of-Sight (NLOS) biases. Convex optimization has played a major role in modelling such problems and numerical algorithm developments. One of the successful examples is the Semi-Definite Programming (SDP), which translates Euclidean distances into the constraints of positi...

The development of future geolocation systems requires a fundamental understanding of the importance of various system parameters, such as the number of sensors, the SNR, bandwidth, and channel conditions. We consider the bounds on time-based geolocation accuracy when all sensors experience non-line-of-sight (NLOS) conditions. While location accuracy generally improves with additional bandwidth...

Herein, results of 5.2 GHz wideband indoor multiple input multiple output (MIMO) channel measurements under the EU IST SATURN project are reported. Our investigation shows that for non-line-of-sight (NLOS) cases, the average power delay profiles fit the exponentially decaying curve quite well, therefore a simple wideband model for singleinput single-output (SISO) proposed in COST259 has been us...

We present the results of multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) channel measurements. The measurements were performed in indoor environments using four transmitters and four receivers with 40MHz bandwidth at 5.25GHz. Our measurements reveal two-dimensional small-scale fading, and correlation between MIMO subchannels. In the line-of-sight (LoS) cas...

The multiple–input–multiple–output (MIMO) technique is the most attractive candidate to improve the spectrum efficiency in the next generation wireless communication systems. However, the efficiency of MIMO techniques reduces in the line of sight (LOS) environments. In this paper, we propose a new MIMO data transmission scheme, which combines Single–Frequency–Network (SFN) with TDD– OFDM–MIMO a...

In this paper an experimental characterization of a typical indoor wireless propagation channel is performed. This channel characterization is needed for short range applications (<10m), utilizing Ultra-Wideband Impulse Radio (UWB-IR) techniques. Both the line of sight (LOS) and the non line of sight (NLOS) scenarios are taken into account. The characterization is done using time domain measure...

This paper considers the channel capacity of 60GHz wireless communications systems over Rayleigh fading channels and Ricean fading channels. The SNR and therefore capacity varies according to the communication distance. The capacity is presented for line-of-sight (LOS) and non-line-of-sight (NLOS) channels given based on a 60GHz link budget model. Phase shift keying (PSK) modulation is consider...

The sparse distribution of targets in monitored areas is an important prior for device-free localization (DFL) with radio tomography networks. In this article, our goal is to develop an enhanced sparse representation-based DFL method that takes the full potential of sparsity for location reconstruction. An expanded sensing matrix spanning the concatenation of a sampling matrix and a unit error-...

Wideband channel measurements at the 60 GHz frequency band in a reflective environment with different antenna heights are presented. The log-distance model of the normalized received power (NRP) is used to fit the measured data for both line-of-sight (LOS) and non-line-of-sight (NLOS) cases. Also, the impact of the biconical antennas and the reflective environment on the channel properties is a...

This paper aims at proposing a new wireless indoor localization system (ILS), called TrackCC, based on a commercial type of low-power system-on-chip (SoC), nRF24LE1. This type of chip has only l output power levels and acute fluctuation for a received minimum power level in operation, which give rise to many practical challenges for designing localization algorithms. In order to address these c...