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Chirp spread spectrum (CSS) technique is capable of providing high processing gain, low power, robustness to multipath interference and immunity to Doppler frequency offset. The paper presents a new phase-coded modulation technique for CSS multiuser communication. The construction of a nth power chirp signal is explained and the design of the phase-coded linear chirp signal is presented in detail...
Opportunity detection at secondary transmitters (TXs) is a key technique enabling cognitive radio (CR) networks. Such detection however cannot guarantee reliable communication at secondary receivers (RXs), especially when their association distance is long. To cope with the issue, this paper proposes a novel MAC called sense-and-predict (SaP), where each secondary TX decides whether to access or not...
Higher spectrum efficiency is a target of the 5th generation (5G) mobile communications system. Massive MIMO is considered as one of important technologies for that purpose. Under the practical conditions that the number of antennas on user equipment (UE) is limited, multi-user MIMO (MU-MIMO) is a probable use scenario of Massive MIMO. Furthermore, massive connectivity is another important target,...
Random stepped FM radar that transmits random frequency narrowband pulses can avoid interference between adjacent radar systems. The random stepped FM radar also offers spectrum hole since it consists of independent pulses with different frequency. Thus it is expected to coexist with the existing radar systems. In this paper, we propose to adopt Khatri-Rao product array processing to spectrum hole...
Methods of modern GNNS organization, their frequency bandwidth and signals generation were described. Nowadays bandwidth for every field of concern is strongly limited. Popularity of radionavigation leads to overlapping spectrum. Modern GNSS are using signals with CDMA to minimize interference. The signals non-orthogonality interference are named multiple-access interference. The multiple-access interference...
In wireless communication systems, frequency-hopping spread spectrum and direct sequence spread spectrum are two main spread coding technologies. Frequency-hopping sequence (FHS) plays an important role in frequency-hopping spread spectrum systems. In this paper, a new class of FHS based on Cyclotomy is constructed. New FHS has new parameters not covered in the literature. It is shown that new FHS...
Multi-replicA decoding using corRelation baSed LocALisAtion (MARSALA) is a recent random access technique designed for satellite return links. It follows the multiple transmission and interference cancellation scheme of Contention Resolution Diversity Slotted Aloha (CRDSA). In addition, at the receiver side, MARSALA uses autocorrelation to localise replicas of a same packet so as to coherently combine...
GNSS signals are vulnerable to various types of interference including jamming and spoofing attacks. Spoofing signals are designed to deceive target GNSS receivers without being detected by conventional receiver quality monitoring metrics. This paper focuses on detecting an overlapped spoofing attack where the correlation peaks of the authentic and spoofing signals interact during the attack. Several...
The correlation of interference has been well quantified in Poisson networks where the interferers are independent of each other. However, there exists dependence among the base stations (BSs) in wireless networks. In view of this, we study the interference correlation in non-Poisson networks where the interferers are distributed as a Matern cluster process (MCP) and a second-order cluster process...
This paper studies a transmission scheme for in-band full-duplex communication system, which is established on the base of complementary codes. Having ideal correlation properties, complementary codes are capable of providing effective mitigation of self-interference (SI) introduced by co-frequency co-time full-duplex (CCFD) communications, an efficient multiple access for multiple users as well as...
This paper presents a new embedding strategy to extend the performance bound of spread spectrum (SS) based watermarking by introducing more imperceptible distortions measured in the mean square errors (MSE). The potential of the host is sufficiently exploited and utilized to maximize the watermark robustness. This strategy is then realized in audio watermarking by adaptively inverting the host according...
A possible approach to address spectrum congestion is to develop signaling schemes that allow for spectrum sharing with minimum system interference. In this paper, we consider the problem of co-existence between radar and communications systems by designing a common signaling scheme to jointly optimize the performance of both systems. In particular, we derive constraints on the parameters of linear...
This paper presents a novel array configuration based on the combination of the sum and difference co-arrays. There have been many studies on the array antenna configurations which enhances the array degree of freedom (DOF), however the maximum DOF of the configurations based on the difference co-array is often limited. We try to further enhance the DOF by combining the concepts of the sum coarray...
The research is devoted to the reduction of multiple access interference (MAI) in chaos-based asynchronous direct sequence code division multiple access (DS-CDMA) communication systems by use of spreading sequences which are selected from a large set of generated chaotic sequences. For the generation of binary chaotic spreading sequences different 1-dimensional maps are examined. As selection criteria...
Inspired by the success of multi-carrier waveforms such as Orthogonal Frequency Division Multiplexing (OFDM) in radio communication, multi-carrier based radar waveform designs have gained strong interest recently. Reasons for this include their resistance to multipath fading, ability to overcome the limitations of a congested frequency spectrum, ability to exploit frequency diversity gains, and potential...
This paper evaluates the simultaneous impact of antenna correlation and imperfect channel state information (CSI) on the sum rate achievable in the compound multiple-input multiple-output (MIMO) Broadcast Channel (BC). The considered correlation model incorporates the correlation due to the proximity of antenna elements at both transmitter and receiver sides. We analyse the achievable sum rate and...
Transform domain communication system (TDCS) has been proposed to support multiuser communications through spectrum bin nulling and frequency domain spreading for overlay cognitive radio networks. In TDCS systems, specific pseudorandom spreading sequences are assigned to different users for the purpose of multiple access. However, due to the non-zero cross-correlations between any pair of TDCS signals,...
This paper is aimed at presenting a new algorithm for multi-path interference resolutions under mirror-based full 3D capture using a single correlation-based ToF camera. Our algorithm does not require additional captures or device modifications, and resolves the interference using a single ToF sensing that is also used for the 3D reconstruction as well. Evaluations with real images prove the concept...
In this contribution, a cyclic-TDOA methodology is simulated. The simulation is a preliminary study that would allow to design and to implement an indoor optical-positioning system relaxing the synchronization requirements among receivers. The synchronism requirement relaxations are carried out by the modification of the structure of the positioning system considering an emitter beacon formed with...
The concept of pairing confidential-relevant variables (connected variables) using ridge regression and bootstrap sampling has recently been proposed for developing perturbation models to data privacy in cyber-physical systems. In this approach, a single set of perturbation parameters for all the pairs of connected variables has been used to achieve trade-off between data confidentiality and classification...
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