Biblio

Filters: Keyword is radio transmitters  [Clear All Filters]
2020-12-14
Wang, H., Ma, L., Bai, H..  2020.  A Three-tier Scheme for Sybil Attack Detection in Wireless Sensor Networks. 2020 5th International Conference on Computer and Communication Systems (ICCCS). :752–756.
Wireless sensor network (WSN) is a wireless self-organizing multi-hop network that can sense and collect the information of the monitored environment through a certain number of sensor nodes which deployed in a certain area and transmit the collected information to the client. Due to the limited power and data capacity stored by the micro sensor, it is weak in communication with other nodes, data storage and calculation, and is very vulnerable to attack and harm to the entire network. The Sybil attack is a classic example. Sybil attack refers to the attack in which malicious nodes forge multiple node identities to participate in network operation. Malicious attackers can forge multiple node identities to participate in data forwarding. So that the data obtained by the end user without any use value. In this paper, we propose a three-tier detection scheme for the Sybil node in the severe environment. Every sensor node will determine whether they are Sybil nodes through the first-level and second-level high-energy node detection. Finally, the base station determines whether the Sybil node detected by the first two stages is true Sybil node. The simulation results show that our proposed scheme significantly improves network lifetime, and effectively improves the accuracy of Sybil node detection.
2021-06-28
Liu, Jia, Fu, Hongchuan, Chen, Yunhua, Shi, Zhiping.  2020.  A Trust-based Message Passing Algorithm against Persistent SSDF. 2020 IEEE 20th International Conference on Communication Technology (ICCT). :1112–1115.
As a key technology in cognitive radio, cooperative spectrum sensing has been paid more and more attention. In cooperative spectrum sensing, multi-user cooperative spectrum sensing can effectively alleviate the performance degradation caused by multipath effect and shadow fading, and improve the spectrum utilization. However, as there may be malicious users in the cooperative sensing users, sending forged false messages to the fusion center or neighbor nodes to mislead them to make wrong judgments, which will greatly reduce the spectrum utilization. To solve this problem, this paper proposes an intelligent anti spectrum sensing data falsification (SSDF) attack algorithm using trust-based non consensus message passing algorithm. In this scheme, only one perception is needed, and the historical propagation path of each message is taken as the basis to calculate the reputation of each cognitive user. Every time a node receives different messages from the same cognitive user, there must be malicious users in its propagation path. We reward the nodes that appear more times in different paths with reputation value, and punish the nodes that appear less. Finally, the real value of the tampered message is restored according to the calculated reputation value. The MATLAB results show that the proposed scheme has a high recovery rate for messages and can identify malicious users in the network at the same time.
2021-04-08
Ekşim, A., Demirci, T..  2020.  Ultimate Secrecy in Cooperative and Multi-hop Wireless Communications. 2020 XXXIIIrd General Assembly and Scientific Symposium of the International Union of Radio Science. :1–4.
In this work, communication secrecy in cooperative and multi-hop wireless communications for various radio frequencies are examined. Attenuation lines and ranges of both detection and ultimate secrecy regions were calculated for cooperative communication channel and multi-hop channel with various number of hops. From results, frequency ranges with the highest potential to apply bandwidth saving method known as frequency reuse were determined and compared to point-to-point channel. Frequencies with the highest attenuation were derived and their ranges of both detection and ultimate secrecy are calculated. Point-to-point, cooperative and multi-hop channels were compared in terms of ultimate secrecy ranges. Multi-hop channel measurements were made with different number of hops and the relation between the number of hops and communication security is examined. Ultimate secrecy ranges were calculated up to 1 Terahertz and found to be less than 13 meters between 550-565 GHz frequency range. Therefore, for short-range wireless communication systems such as indoor and in-device communication systems (board-to-board or chip-to-chip communications), it is shown that various bands in the Terahertz band can be used to reuse the same frequency in different locations to obtain high security and high bandwidth.
2021-01-20
Shi, F., Chen, Z., Cheng, X..  2020.  Behavior Modeling and Individual Recognition of Sonar Transmitter for Secure Communication in UASNs. IEEE Access. 8:2447—2454.

It is necessary to improve the safety of the underwater acoustic sensor networks (UASNs) since it is mostly used in the military industry. Specific emitter identification is the process of identifying different transmitters based on the radio frequency fingerprint extracted from the received signal. The sonar transmitter is a typical low-frequency radiation source and is an important part of the UASNs. Class D power amplifier, a typical nonlinear amplifier, is usually used in sonar transmitters. The inherent nonlinearity of power amplifiers provides fingerprint features that can be distinguished without transmitters for specific emitter recognition. First, the nonlinearity of the sonar transmitter is studied in-depth, and the nonlinearity of the power amplifier is modeled and its nonlinearity characteristics are analyzed. After obtaining the nonlinear model of an amplifier, a similar amplifier in practical application is obtained by changing its model parameters as the research object. The output signals are collected by giving the same input of different models, and, then, the output signals are extracted and classified. In this paper, the memory polynomial model is used to model the amplifier. The power spectrum features of the output signals are extracted as fingerprint features. Then, the dimensionality of the high-dimensional features is reduced. Finally, the classifier is used to recognize the amplifier. The experimental results show that the individual sonar transmitter can be well identified by using the nonlinear characteristics of the signal. By this way, this method can enhance the communication safety of the UASNs.

2020-12-28
Khatod, V., Manolova, A..  2020.  Effects of Man in the Middle (MITM) Attack on Bit Error Rate of Bluetooth System. 2020 Joint International Conference on Digital Arts, Media and Technology with ECTI Northern Section Conference on Electrical, Electronics, Computer and Telecommunications Engineering (ECTI DAMT NCON). :153—157.
The ad-hoc network formed by Bluetooth works on radio frequency links. The security aspect of Bluetooth has to be handled more carefully. The radio frequency waves have a characteristic that the waves can pierce the obstructions in the communication path, get rid of the requirement of line of sight between the communicating devices. We propose a software model of man-in-the-middle attack along with unauthorized and authorized transmitter and receiver. Advanced White Gaussian Noise channel is simulated in the designed architecture. The transmitter uses Gaussian Frequency Shift Keying (GFSK) modulation like in Bluetooth. The receiver uses GFSK demodulation. In order to validate the performance of the designed system, bit error rate (BER) measurements are taken with respect to different time intervals. We found that BER drops roughly 18% if hopping duration of 150 seconds is chosen. We propose that a Bluetooth system with hopping rate of 0.006 Hz is used instead of 10Hz.
2021-06-30
DelVecchio, Matthew, Flowers, Bryse, Headley, William C..  2020.  Effects of Forward Error Correction on Communications Aware Evasion Attacks. 2020 IEEE 31st Annual International Symposium on Personal, Indoor and Mobile Radio Communications. :1—7.
Recent work has shown the impact of adversarial machine learning on deep neural networks (DNNs) developed for Radio Frequency Machine Learning (RFML) applications. While these attacks have been shown to be successful in disrupting the performance of an eavesdropper, they fail to fully support the primary goal of successful intended communication. To remedy this, a communications-aware attack framework was recently developed that allows for a more effective balance between the opposing goals of evasion and intended communication through the novel use of a DNN to intelligently create the adversarial communication signal. Given the near ubiquitous usage of for-ward error correction (FEC) coding in the majority of deployed systems to correct errors that arise, incorporating FEC in this framework is a natural extension of this prior work and will allow for improved performance in more adverse environments. This work therefore provides contributions to the framework through improved loss functions and design considerations to incorporate inherent knowledge of the usage of FEC codes within the transmitted signal. Performance analysis shows that FEC coding improves the communications aware adversarial attack even if no explicit knowledge of the coding scheme is assumed and allows for improved performance over the prior art in balancing the opposing goals of evasion and intended communications.
2020-02-17
Liu, Xiaochen, Gao, Yuanyuan, Zang, Guozhen, Sha, Nan.  2019.  Artificial-Noise-Aided Robust Beamforming for MISOME Wiretap Channels with Security QoS. 2019 IEEE 19th International Conference on Communication Technology (ICCT). :795–799.
This paper studies secure communication from a multi-antenna transmitter to a single-antenna receiver in the presence of multiple multi-antenna eavesdroppers, considering constraints of security quality of service (QoS), i.e., minimum allowable signal-to-interference-and-noise ratio (SINR) at receiver and maximum tolerable SINR at eavesdroppers. The robust joint optimal beamforming (RJOBF) of secret signal and artificial noise (AN) is designed to minimize transmit power while estimation errors of channel state information (CSI) for wiretap channels are taken into consideration. The formulated design problem is shown to be nonconvex and we transfer it into linear matrix inequalities (LMIs) along with semidefinite relaxation (SDR) technique. The simulation results illustrate that our proposed RJOBF is efficient for power saving in security communication.
Lin, Yun, Chang, Jie.  2019.  Improving Wireless Network Security Based On Radio Fingerprinting. 2019 IEEE 19th International Conference on Software Quality, Reliability and Security Companion (QRS-C). :375–379.
With the rapid development of the popularity of wireless networks, there are also increasing security threats that follow, and wireless network security issues are becoming increasingly important. Radio frequency fingerprints generated by device tolerance in wireless device transmitters have physical characteristics that are difficult to clone, and can be used for identity authentication of wireless devices. In this paper, we propose a radio frequency fingerprint extraction method based on fractional Fourier transform for transient signals. After getting the features of the signal, we use RPCA to reduce the dimension of the features, and then use KNN to classify them. The results show that when the SNR is 20dB, the recognition rate of this method is close to 100%.
2020-08-10
Liao, Runfa, Wen, Hong, Pan, Fei, Song, Huanhuan, Xu, Aidong, Jiang, Yixin.  2019.  A Novel Physical Layer Authentication Method with Convolutional Neural Network. 2019 IEEE International Conference on Artificial Intelligence and Computer Applications (ICAICA). :231–235.
This paper investigates the physical layer (PHY-layer) authentication that exploits channel state information (CSI) to enhance multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) system security by detecting spoofing attacks in wireless networks. A multi-user authentication system is proposed using convolutional neural networks (CNNs) which also can distinguish spoofers effectively. In addition, the mini batch scheme is used to train the neural networks and accelerate the training speed. Meanwhile, L1 regularization is adopted to prevent over-fitting and improve the authentication accuracy. The convolutional-neural-network-based (CNN-based) approach can authenticate legitimate users and detect attackers by CSIs with higher performances comparing to traditional hypothesis test based methods.
2020-11-09
Ekşim, A., Demirci, T..  2019.  Ultimate Secrecy in Wireless Communications. 2019 11th International Conference on Electrical and Electronics Engineering (ELECO). :682–686.
In this work, communication secrecy in the physical layer for various radio frequencies is examined. Frequencies with the highest level of secrecy in 1-1000 GHz range and their level of communication secrecy are derived. The concept of ultimate secrecy in wireless communications is proposed. Attenuation lines and ranges of both detection and ultimate secrecy are calculated for transmitter powers from 1 W to 1000 W. From results, frequencies with the highest potential to apply bandwidth saving method known as frequency reuse are devised. Commonly used secrecy benchmarks for the given conditions are calculated. Frequencies with the highest attenuation are devised and their ranges of both detection and ultimate secrecy are calculated.
2020-07-03
Viegas, P., Borges, D., Montezuma, P., Dinis, R., Silva, M. M..  2019.  Multi-beam Physical Security Scheme: Security Assessment and Impact of Array Impairments on Security and Quality of Service. 2019 PhotonIcs Electromagnetics Research Symposium - Spring (PIERS-Spring). :2368—2375.

Massive multiple-input multiple-output (mMIMO) with perfect channel state information (CSI) can lead array power gain increments proportional to the number of antennas. Despite this fact constrains on power amplification still exist due to envelope variations of high order constellation signals. These constrains can be overpassed by a transmitter with several amplification branches, with each one associated to a component signal that results from the decomposition of a multilevel constellation as a sum of several quasi constant envelope signals that are sent independently. When combined with antenna arrays at the end of each amplification branch the security improves due to the energy separation achieved by beamforming. However, to avoid distortion on the signal resulting from the combination of all components at channel level all the beams of signal components should be directed in same direction. In such conditions it is crucial to assess the impact of misalignments between beams associated to each user, which is the purpose of this work. The set of results presented here show the good tolerance against misalignments of these transmission structures.

2019-12-05
Mu, Li, Mianquan, Li, Yuzhen, Huang, Hao, Yin, Yan, Wang, Baoquan, Ren, Xiaofei, Qu, Rui, Yu.  2018.  Security Analysis of Overlay Cognitive Wireless Networks with an Untrusted Secondary User. 2018 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC). :1-5.

In this article, we study the transmission secrecy performance of primary user in overlay cognitive wireless networks, in which an untrusted energy-limited secondary cooperative user assists the primary transmission to exchange for the spectrum resource. In the network, the information can be simultaneously transmitted through the direct and relay links. For the enhancement of primary transmission security, a maximum ratio combining (MRC) scheme is utilized by the receiver to exploit the two copies of source information. For the security analysis, we firstly derive the tight lower bound expression for secrecy outage probability (SOP). Then, three asymptotic expressions for SOP are also expressed to further analyze the impacts of the transmit power and the location of secondary cooperative node on the primary user information security. The findings show that the primary user information secrecy performance enhances with the improvement of transmit power. Moreover, the smaller the distance between the secondary node and the destination, the better the primary secrecy performance.

2019-03-15
Yazicigil, R. T., Nadeau, P., Richman, D., Juvekar, C., Vaidya, K., Chandrakasan, A. P..  2018.  Ultra-Fast Bit-Level Frequency-Hopping Transmitter for Securing Low-Power Wireless Devices. 2018 IEEE Radio Frequency Integrated Circuits Symposium (RFIC). :176-179.

Current BLE transmitters are susceptible to selective jamming due to long dwell times in a channel. To mitigate these attacks, we propose physical-layer security through an ultra-fast bit-level frequency-hopping (FH) scheme by exploiting the frequency agility of bulk acoustic wave resonators (BAW). Here we demonstrate the first integrated bit-level FH transmitter (TX) that hops at 1$μ$s period and uses data-driven random dynamic channel selection to enable secure wireless communications with additional data encryption. This system consists of a time-interleaved BAW-based TX implemented in 65nm CMOS technology with 80MHz coverage in the 2.4GHz ISM band and a measured power consumption of 10.9mW from 1.1V supply.

2020-09-28
Sliwa, Benjamin, Haferkamp, Marcus, Al-Askary, Manar, Dorn, Dennis, Wietfeld, Christian.  2018.  A radio-fingerprinting-based vehicle classification system for intelligent traffic control in smart cities. 2018 Annual IEEE International Systems Conference (SysCon). :1–5.
The measurement and provision of precise and up-to-date traffic-related key performance indicators is a key element and crucial factor for intelligent traffic control systems in upcoming smart cities. The street network is considered as a highly-dynamic Cyber Physical System (CPS) where measured information forms the foundation for dynamic control methods aiming to optimize the overall system state. Apart from global system parameters like traffic flow and density, specific data, such as velocity of individual vehicles as well as vehicle type information, can be leveraged for highly sophisticated traffic control methods like dynamic type-specific lane assignments. Consequently, solutions for acquiring these kinds of information are required and have to comply with strict requirements ranging from accuracy over cost-efficiency to privacy preservation. In this paper, we present a system for classifying vehicles based on their radio-fingerprint. In contrast to other approaches, the proposed system is able to provide real-time capable and precise vehicle classification as well as cost-efficient installation and maintenance, privacy preservation and weather independence. The system performance in terms of accuracy and resource-efficiency is evaluated in the field using comprehensive measurements. Using a machine learning based approach, the resulting success ratio for classifying cars and trucks is above 99%.
2019-12-05
Yadav, Kuldeep, Roy, Sanjay Dhar, Kundu, Sumit.  2018.  Total Error Reduction in Presence of Malicious User in a Cognitive Radio Network. 2018 2nd International Conference on Electronics, Materials Engineering Nano-Technology (IEMENTech). :1-4.

Primary user emulation (PUE) attack causes security issues in a cognitive radio network (CRN) while sensing the unused spectrum. In PUE attack, malicious users transmit an emulated primary signal in spectrum sensing interval to secondary users (SUs) to forestall them from accessing the primary user (PU) spectrum bands. In the present paper, the defense against such attack by Neyman-Pearson criterion is shown in terms of total error probability. Impact of several parameters such as attacker strength, attacker's presence probability, and signal-to-noise ratio on SU is shown. Result shows proposed method protect the harmful effects of PUE attack in spectrum sensing.

2017-12-20
Wang, Fei, Zhang, Xi.  2017.  Secure resource allocation for polarization-enabled green cooperative cognitive radio networks with untrusted secondary users. 2017 51st Annual Conference on Information Sciences and Systems (CISS). :1–6.
We address secure resource allocation for an OFDMA cooperative cognitive radio network (CRN) with energy harvesting (EH) capability. In the network, one primary user (PU) cooperates with several untrusted secondary users (SUs) with one SU transmitter and several SU receivers, where the SU transmitter and all SU receivers may overhear the PU transmitter's information while all SU receivers may eavesdrop on each other's signals. We consider the scenario when SUs are wireless devices with small physical sizes; therefore to improve system performance we suppose that SUs are equipped with co-located orthogonally dual-polarized antennas (ODPAs). With ODPAs, on one hand, the SU transmitter can first harvest energy from radio frequency (RF) signals emitted by the PU transmitter, and then utilize the harvested energy to simultaneously serve the PU and all SU receivers. On the other hand, by exploiting polarization-based signal processing techniques, both the PU's and SUs' physical-layer security can be enhanced. In particular, to ensure the PU's communication security, the PU receiver also sends jamming signals to degrade the reception performance of SUs, and meanwhile the jamming signals can also become new sources of energy powering the SU transmitter. For the considered scenario, we investigate the joint allocation of subcarriers, powers, and power splitting ratios to maximize the total secrecy rate of all SUs while ensuring the PU's minimum secrecy rate requirement. Finally, we evaluate the performance of our resource allocation scheme through numerical analyses.
Lin, J., Li, Q., Yang, J..  2017.  Frequency diverse array beamforming for physical-layer security with directionally-aligned legitimate user and eavesdropper. 2017 25th European Signal Processing Conference (EUSIPCO). :2166–2170.
The conventional physical-layer (PHY) security approaches, e.g., transmit beamforming and artificial noise (AN)-based design, may fail when the channels of legitimate user (LU) and eavesdropper (Eve) are close correlated. Due to the highly directional transmission feature of millimeter-wave (mmWave), this may occur in mmWave transmissions as the transmitter, Eve and LU are aligned in the same direction exactly. To handle the PHY security problem with directionally-aligned LU and Eve, we propose a novel frequency diverse array (FDA) beamforming approach to differentiating the LU and Eve. By intentionally introducing some frequency offsets across the antennas, the FDA beamforming generates an angle-range dependent beampattern. As a consequence, it can degrade the Eve's reception and thus achieve PHY security. In this paper, we maximize the secrecy rate by jointly optimizing the frequency offsets and the beamformer. This secrecy rate maximization (SRM) problem is hard to solve due to the tightly coupled variables. Nevertheless, we show that it can be reformulated into a form depending only on the frequency offsets. Building upon this reformulation, we identify some cases where the SRM problem can be optimally solved in closed form. Numerical results demonstrate the efficacy of FDA beamforming in achieving PHY security, even for aligned LU and Eve.
2017-12-12
Lee, S. H., Wang, L., Khisti, A., Womell, G. W..  2017.  Covert communication with noncausal channel-state information at the transmitter. 2017 IEEE International Symposium on Information Theory (ISIT). :2830–2834.

We consider the problem of covert communication over a state-dependent channel, where the transmitter has non-causal knowledge of the channel states. Here, “covert” means that the probability that a warden on the channel can detect the communication must be small. In contrast with traditional models without noncausal channel-state information at the transmitter, we show that covert communication can be possible with positive rate. We derive closed-form formulas for the maximum achievable covert communication rate (“covert capacity”) in this setting for discrete memoryless channels as well as additive white Gaussian noise channels. We also derive lower bounds on the rate of the secret key that is needed for the transmitter and the receiver to achieve the covert capacity.

2018-10-26
Subramani, K. S., Antonopoulos, A., Abotabl, A. A., Nosratinia, A., Makris, Y..  2017.  INFECT: INconspicuous FEC-based Trojan: A hardware attack on an 802.11a/g wireless network. 2017 IEEE International Symposium on Hardware Oriented Security and Trust (HOST). :90–94.

We discuss the threat that hardware Trojans (HTs) impose on wireless networks, along with possible remedies for mitigating the risk. We first present an HT attack on an 802.11a/g transmitter (TX), which exploits Forward Error Correction (FEC) encoding. While FEC seeks to protect the transmitted signal against channel noise, it often offers more protection than needed by the actual channel. This margin is precisely where our HT finds room to stage an attack. We, then, introduce a Trojan-agnostic method which can be applied at the receiver (RX) to detect such attacks. This method monitors the noise distribution, to identify systematic inconsistencies which may be caused by an HT. Lastly, we describe a Wireless open-Access Research Platform (WARP) based experimental setup to investigate the feasibility and effectiveness of the proposed attack and defense. More specifically, we evaluate (i) the ability of a rogue RX to extract the leaked information, while an unsuspecting, legitimate RX accurately recovers the original message and remains oblivious to the attack, and (ii) the ability of channel noise profiling to detect the presence of the HT.

2018-03-19
Ward, T., Choi, J. I., Butler, K., Shea, J. M., Traynor, P., Wong, T. F..  2017.  Privacy Preserving Localization Using a Distributed Particle Filtering Protocol. MILCOM 2017 - 2017 IEEE Military Communications Conference (MILCOM). :835–840.

Cooperative spectrum sensing is often necessary in cognitive radios systems to localize a transmitter by fusing the measurements from multiple sensing radios. However, revealing spectrum sensing information also generally leaks information about the location of the radio that made those measurements. We propose a protocol for performing cooperative spectrum sensing while preserving the privacy of the sensing radios. In this protocol, radios fuse sensing information through a distributed particle filter based on a tree structure. All sensing information is encrypted using public-key cryptography, and one of the radios serves as an anonymizer, whose role is to break the connection between the sensing radios and the public keys they use. We consider a semi-honest (honest-but-curious) adversary model in which there is at most a single adversary that is internal to the sensing network and complies with the specified protocol but wishes to determine information about the other participants. Under this scenario, an adversary may learn the sensing information of some of the radios, but it does not have any way to tie that information to a particular radio's identity. We test the performance of our proposed distributed, tree-based particle filter using physical measurements of FM broadcast stations.

2017-12-27
Kharel, R., Raza, U., Ijaz, M., Ekpo, S., Busawon, K..  2016.  Chaotic secure digital communication scheme using auxiliary systems. 2016 10th International Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP). :1–6.

In this paper, we present a new secure message transmission scheme using hyperchaotic discrete primary and auxiliary chaotic systems. The novelty lies on the use of auxiliary chaotic systems for the encryption purposes. We have used the modified Henon hyperchaotic discrete-time system. The use of the auxiliary system allows generating the same keystream in the transmitter and receiver side and the initial conditions in the auxiliary systems combined with other transmitter parameters suffice the role of the key. The use of auxiliary systems will mean that the information of keystream used in the encryption function will not be present on the transmitted signal available to the intruders, hence the reconstructing of the keystream will not be possible. The encrypted message is added on to the dynamics of the transmitter using inclusion technique and the dynamical left inversion technique is employed to retrieve the unknown message. The simulation results confirm the robustness of the method used and some comments are made about the key space from the cryptographic viewpoint.

2017-02-21
M. B. Amin, W. Zirwas, M. Haardt.  2015.  "Advanced channel prediction concepts for 5G radio systems". 2015 International Symposium on Wireless Communication Systems (ISWCS). :166-170.

Massive MIMO and tight cooperation between transmission nodes are expected to become an integral part of a future 5G radio system. As part of an overall interference mitigation scheme substantial gains in coverage, spectral as well as energy efficiency have been reported. One of the main limitations for massive MIMO and coordinated multi-point (CoMP) systems is the aging of the channel state information at the transmitter (CSIT), which can be overcome partly by state of the art channel prediction techniques. For a clean slate 5G radio system, we propose to integrate channel prediction from the scratch in a flexible manner to benefit from future improvements in this area. As any prediction is unreliable by nature, further improvements over the state of the art are needed for a convincing solution. In this paper, we explain how the basic ingredients of 5G like base stations with massive MIMO antenna arrays, and multiple UE antennas can help to stretch today's limits with an approximately 10 dB lower normalized mean square error (NMSE) of the predicted channel. In combination with the novel introduced concept of artificially mutually coupled antennas, adding super-directivity gains to virtual beamforming, robust and accurate prediction over 10 ms with an NMSE of -20 dB up to 15 km/h at 2.6 GHz RF frequency could be achieved. This result has been achieved for measured channels without massive MIMO, but a comparison with ray-traced channels for the same scenario is provided as well.

2017-02-14
R. Saravanan, V. Saminadan, V. Thirunavukkarasu.  2015.  "VLSI implementation of BER measurement for wireless communication system". 2015 International Conference on Innovations in Information, Embedded and Communication Systems (ICIIECS). :1-5.

This paper presents the Bit Error Rate (BER) performance of the wireless communication system. The complexity of modern wireless communication system are increasing at fast pace. It becomes challenging to design the hardware of wireless system. The proposed system consists of MIMO transmitter and MIMO receiver along with the along with a realistic fading channel. To make the data transmission more secure when the data are passed into channel Crypto-System with Embedded Error Control (CSEEC) is used. The system supports data security and reliability using forward error correction codes (FEC). Security is provided through the use of a new symmetric encryption algorithm, and reliability is provided by the use of FEC codes. The system aims at speeding up the encryption and encoding operations and reduces the hardware dedicated to each of these operations. The proposed system allows users to achieve more security and reliable communication. The proposed BER measurement communication system consumes low power compared to existing systems. Advantage of VLSI based BER measurement it that they can be used in the Real time applications and it provides single chip solution.

2017-03-08
Luo, Z., Gilimyanov, R., Zhuang, H., Zhang, J..  2015.  Network-Wide Optimization of Uplink Fractional Power Control in LTE Networks. 2015 IEEE 82nd Vehicular Technology Conference (VTC2015-Fall). :1–5.

Next generation cellular networks will provide users better experiences by densely deploying smaller cells, which results in more complicated interferences environment. In order to coordinate interference, power control for uplink is particularly challenging due to random locations of uplink transmitter and dense deployment. In this paper, we address the uplink fractional power control (FPC) optimization problem from network optimization perspective. The relations between FPC parameters and network KPIs (Key Performance Indicators) are investigated. Rather than considering any single KPI in conventional approaches, multi-KPI optimization problem is formulated and solved. By relaxing the discrete optimization problem to a continuous one, the gradients of multiple KPIs with respect to FPC parameters are derived. The gradient enables efficiently searching for optimized FPC parameters which is particularly desirable for dense deployment of large number of cells. Simulation results show that the proposed scheme greatly outperforms the traditional one, in terms of network mean load, call drop & block ratio, and convergence speed.

2015-04-30
Ta-Yuan Liu, Mukherjee, P., Ulukus, S., Shih-Chun Lin, Hong, Y.-W.P..  2014.  Secure DoF of MIMO Rayleigh block fading wiretap channels with No CSI anywhere. Communications (ICC), 2014 IEEE International Conference on. :1959-1964.

We consider the block Rayleigh fading multiple-input multiple-output (MIMO) wiretap channel with no prior channel state information (CSI) available at any of the terminals. The channel gains remain constant in a coherence time of T symbols, and then change to another independent realization. The transmitter, the legitimate receiver and the eavesdropper have nt, nr and ne antennas, respectively. We determine the exact secure degrees of freedom (s.d.o.f.) of this system when T ≥ 2 min(nt, nr). We show that, in this case, the s.d.o.f. is exactly (min(nt, nr) - ne)+(T - min(nt, nr))/T. The first term can be interpreted as the eavesdropper with ne antennas taking away ne antennas from both the transmitter and the legitimate receiver. The second term can be interpreted as a fraction of s.d.o.f. being lost due to the lack of CSI at the legitimate receiver. In particular, the fraction loss, min(nt, nr)/T, can be interpreted as the fraction of channel uses dedicated to training the legitimate receiver for it to learn its own CSI. We prove that this s.d.o.f. can be achieved by employing a constant norm channel input, which can be viewed as a generalization of discrete signalling to multiple dimensions.