Platform logo
Explore Communities
Profile Avatar
Jehad Hamamreh
Antalya international University

07/02/2019| By
Jehad Jehad M. Hamamreh

Polar codes, recently accepted for adoption in 5G standard due to their excellent performance at a very low complexity compared to other competitive schemes in the literature, are deemed to be a strong candidate for the Internet of Things (IoT) applications as well due to meeting their requirements. However, since polar codes construction is naturally channel-dependent, there has recently been an increasing interest in addressing the challenge of making polar codes work in realistic fading environments as they do in a binary symmetric channel (BSC). Recent studies on polar codes for fading channels have mainly focused on constructing new specific polar codes suitable to particular fading channels. This results in a non-universal code structure, leading to continuous changes in the code structure based on the channel, which is not desirable in practice. To address this problem, we develop and propose a novel transceiver architecture which enables using the polar coding design of a binary input additive white Gaussian noise (BI-AWGN) channel for multi-path fading channels without causing any changes in the structure of the encoder and decoder sides. This is made possible by eliminating the channel fading effect so that a net AWGN channel can be seen at the input of a simple successive cancellation decoder (SCD). The novelty of the proposed solution lies in using a channel-based orthonormal transformation with optimal power allocation at the transmitter and another transformation at the receiver to make the net, effective channel seen by the SCD very similar to an AWGN channel. The obtained results show that the proposed design makes the bit error rate (BER) performance of polar codes over a frequency selective fading channel the same as that over an AWGN channel. As a plus, great advantage, the proposed design is found to be capable of providing confidentiality against eavesdropping receivers (i.e., unintended users) at the physical layer. Particularly, wireless physical layer security is delivered by the proposed scheme because of the fact that the transmitted data blocks are designed based on the channel of the legitimate receiver, which is naturally different from that of an eavesdropper, who is normally located several wavelengths away from the legitimate receiver, and thus experiencing a different channel.

 21 views
07/02/2019| By
Jehad Jehad M. Hamamreh

Drones or unmanned aerial vehicles (UAVs) communication technology, which has recently been thoroughly studied and adopted by 3GPP standard (Release 15) due to its dynamic, flexible, and flying nature, is expected to be an integral part of future wireless communications and Internet of drones (IoD) applications. However, due to the unique transmission characteristics and nature of UAV systems including the broadcasting, dominant line of site and poor scattering, providing confidentiality for legitimate receivers against unintended ones (eavesdroppers) appears to be a challenging goal to achieve in such scenarios. Besides, the special features of UAVs represented by having limited power (battery-operated) and processing (light RAM and CPU capabilities), makes applying complex cryptography approaches very challenging and inefficient for such systems. This motives the utilization of alternative approaches enabled by physical layer security (PLS) concept for securing UAV-based systems. Techniques based on PLS are deemed to be promising due to their ability to provide inherent secrecy that is complexity independent, where no matter what computational processing power the eavesdropper may have, there is no way to decrypt the PLS algorithms. This work is dedicated to highlight and overview the latest advances and state of art researches on the field of applying PLS to UAV systems in a unified and structured manner. Particularity, it discusses and explains the different, possible PLS scenarios and use cases of UAVs, which are categorized based on how the drone is utilized and employed in the communication system setup. The main classified categories include the deployment of the flying, mobile UAV as a 1) base station (BS), 2) user equipment (UE), 2) relay, or 4) jammer. Then, recommendations and future open research issues are stated and discussed.

 43 views
07/02/2019| By
Jehad Jehad M. Hamamreh

Ensuring the security of the Internet of Things (IoT) is deemed as one of the most critical challenges and needs that have to be addressed in order to guarantee the successful deployment of IoT in emerging technologies like 5G. In an effort to address this challenge, in this work, an improved and flexible physical layer security technique referred to as orthogonal frequency division multiplexing with subcarrier index selection and artificially interfering signals (OFDM-SIS-AIS), is developed for protecting the transmission of OFDM-based waveforms against eavesdropping in 5G and beyond wireless networks. In this technique, the frequency response of correlated subchannels is first converted into a completely randomized and independent response by means of adaptive interleaving. Then, the whole OFDM block is divided into small sub-blocks, each containing a set of subcarriers, from which a subset of these subcarriers, which are corresponding to high subchannel gains, are selected and used for data transmission, while the remaining ones, which are corresponding to low subchannel gains, are used for sending artificially interfering signals. The selected subcarriers are determined through an optimization problem that can effectively maximize the signal-to-noise ratio (SNR) at only the legitimate receiver. The obtained results demonstrate a significant improvement in the secrecy gap performance without considering the knowledge of the eavesdropper’s channel nor sharing any keys, while maintaining low complexity and high reliability at the legitimate user. These numerous advantages have the potential to make the proposed scheme a consistent candidate technique for secure IoT-5G based services.

 69 views