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Multi-carrier code division multiple access (MC-CDMA) communications scheme is a promising technology for future wireless communication systems. However, designing a receiver for quasi-asynchronous MC-CDMA and corresponding code still dates a challenging task. We show that fractional-delay uplink channels, suffer while complete complementary code (CCC) and Walsh-Hadamard (WH) code are used. Thus quasi-asynchronous...
With some recent developments in the field of wireless communication at rapid pace, users are getting a number of applications which require the precious bandwidth to work on. As the bandwidth is limited, the available spectrum is being congested day by day. Cognitive Radio System (CRS) plays an important role in such scenario. It dynamically adapts its parameters and protocols to provide unused spaces...
Precise understanding of the sea bottom characteristics and accurate identification of objects on the seabed are critical in many underwater applications. The severe multi-path along with the time varying and random reflections from the surface and the bottom of shallow waters, present an interesting and complex signal processing problem. A thin line hydrophone array, deployed from small Autonomous...
This paper focusses on the urban multipath channel reduction problematic for Global Navigation Satellite Systems (GNSS) receiver performance assessment. First, multipath aggregation methods are compared to parametric methods through channel delay and Doppler characteristics preservation criteria. Then, the impact of these criteria on the GNSS receiver's positioning computation is quantified, in order...
The future of Intelligent Transportation Systems (ITS) relies on a properly constructed Control Transportation System (CTS) based on a dynamically accurate localisation system. In urban scenarios applications for lane detection, as part of intelligent highways, Global Navigation Satellite Systems (GNSS) receivers provide tangential and perpendicular locations for localisation systems, by means of...
Direct GPS Positioning (DP) is a robust method that estimates the GPS navigation solution directly from the received GPS signal. In contrast, traditional methods, such as scalar tracking and vector tracking, compute intermediate channel range and range residual measurements independently, then use these as inputs into the navigation filter to estimate the navigation solution. However, a brute force...
Beidou navigation satellite system (BDS) has provided open services for the most part of the Asia-Pacific region and plans to provide global service in 2020. In the future, it is necessary for BDS to support ARAIM. As an important parameter of ARAIM, the maximum nominal bias (Bnom) of BDS need to be determined. This paper aims to estimate the impact of nominal biases on ARAIM user performance of BDS...
The use of orthogonal waveform can offer many advantages in covert underwater acoustic communication, including improved symbol detection ability. In this paper, we derive a new orthogonal code design. The proposed code has a good autocorrelation property compared to other codes. We present some results of a lake trial to evaluate the performance of the proposed method.
This paper presents a single-hydrophone based method for source range localization from information contained in the multipath propagation in the reliable acoustic path (RAP) environment. The time delays between the direct (D) and the surface-reflected (SR) arrivals are obtained from the autocorrelation of the received signal and are compared with the D-SR time delays predicted by the acoustic model...
Blind channel estimation methods normally use the statistical properties of received signals to restore the original waveform without a priori information. However, these methods need a high computational complexity especially in multipath environments, and their performances are not good enough. A blind channel estimation method utilizing acoustic propagation physics via normal mode is proposed in...
Phasor Measurement Units (PMUs) provide time synchronized electrical measurements at many nodes across the power grid. This wide area time synchronization is made possible via GPS time transfer. Unfortunately, the GPS civilian signal is weak and vulnerable to signal interferences such as jamming and meaconing. As such, the GPS-based time synchronization of PMUs may be a potential point of entry for...
Measurement results show that the motion direction of objects has a significant effect on the deformation of the autocorrelation function (ACF) and the power spectrum density (PSD) of the received signals. However, this fact is not included in the analysis of these characteristics previously presented in the literature. In this paper, ACF and PSD are presented as a function of the receiver (Rx) /...
Machine Type Communication (MTC) device for cellular communication is being defined by 3GPP based on LTE in Rel-12 and Rel-13. Low cost has been the major objective of the definition for Rel-12 based specification. In Rel-13, coverage enhancement of MTC devices has been the major focus along with reduced power consumption, complexity and narrow bandwidth operation. Coverage enhancement (CE) of ∼15dB...
In this paper, we describe and analyze the results of a radio channel measurement campaign in an extreme industrial environment; a large open-pit copper mine targeted by next generation's highly voiced device communications. We present a practical and efficient method to perform robust and high-sensitivity impulse response measurements without a common clock reference using the widely spread USRP...
Zero-tail Discrete Fourier Transform-spread OFDM (ZT DFT-s-OFDM) modulation replaces the Cyclic Prefix (CP) with a low power tail whose length can be dynamically configured to cope with the instantaneous delay spread of the channel. In this paper, we discuss the reference sequence design for ZT DFT-s-OFDM. Our proposed approach is based on a deliberate distortion of the known Zadoff-Chu (ZC) sequences...
In this paper, we describe and analyze the results of a radio channel measurement campaign in an extreme industrial environment; a large open-pit copper mine targeted by next generation's highly voiced device communications. We present a practical and efficient method to perform robust and high-sensitivity impulse response measurements without a common clock reference using the widely spread USRP...
A novel code division multiple access (CDMA) using cyclic shift keying (CSK) signaling, namely CSK-CDMA, has been proposed for multiuser underwater acoustic communication. The proposed method uses the cyclic correlation characteristic of spread spectrum signals and time reversal processing to increase the data rate each user and to reduce the complexity of the receiver. In CSK-CDMA system, multiple...
Given that L-band digital aeronautical communications system type 1 (LDACS1) may share the same spectrum with the legacy Distance Measuring Equipment (DME) system, DME, impulsive interference would be the main issue of this aeronautical communications system. To improve the performance of the LDACS1, a time-domain Correlative Interference Mitigation (CIM) aiming at DME impulse is proposed in this...
This paper presents the results of a dual polarized multiple-input-multiple-output (MIMO) channel measurements, investigating a land mobile satellite (LMS) pedestrian scenario in an urban environment. The channel characterization considers the downlink from a fixed elevated position, emulating a satellite, to a mobile terminal, incorporating line-of-sight (LOS) and non-line-of-sight (NLOS) conditions,...
Many GNSS (Global Navigation Satellites System) applications need high integrity performances. Receiver Autonomous Integrity Monitoring (RAIM), or similar method, is commonly used. Initially developed for aeronautics, RAIM techniques may not be fully adapted for terrestrial navigation, especially in urban environments. Those techniques use basically the pseudoranges to derive an integrity criterion...
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