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Öğe Bit error rate performance of in-vivo radio channel using maximum likelihood sequence estimation(Institute of Electrical and Electronics Engineers Inc., 2020) Mezher, Mohad; Ilyas, Muhammad; Bayat, Oğuz; Abbasi, Qammer H.In this paper we present the Bit Error Rate (BER) performance of equalizers using in-vivo channel response measured using Vector Network Analyzer (VNA). Including the use of a Bandwidth (BW) of 50 MHz in the simulations, the results are compared with multiple equalizers and it is shown that Maximum Likelihood Sequence Estimation (MLSE) equalizer outperformed the rest of the equalizers including linear equalizers Least Mean Square (LMS) and Recursive least sequence (RLS) and non-linear equalizer Decision Feedback Equalizer (DFE). The BER performance using MLSE showed significant improvement by improving the BER and outperforming the linear equalizer from 10-2 to 10-6 and DFE from 10-4 to 10-6 at text{Eb}/ text{No}= 14 dB for in vivo radio communication channel at ultra wideband (UWB) frequencies. Furthermore, the un-equalized and equalized channel frequency response spectrum is also part of this article which presents the overall improvement between the two spectrums. © 2020 IEEE.Öğe Evaluation of ultra-wideband in vivo radio channel and its effects on system performance(Wiley, 2019) İlyas, Muhammad; Uçan, Osman Nuri; Bayat, Oğuz; Nasir, Ali Arshad; Imran, Muhammad Ali; Alomainy, Akram; Abbasi, Qammer H.This paper presents bit-error-rate (BER) performance analysis and improvement using equalizers for an in vivo radio channel at ultra-wideband frequencies (3.1 GHz to 10.6 GHz). By conducting simulations using a bandwidth of 50 MHz, we observed that the in vivo radio channel is affected by small-scale fading. This fading results in intersymbol interference affecting upcoming symbol transmission, causing delayed versions of the symbols to arrive at the receiver side and causes increase in BER. A 29-taps channel was observed from the experimentally measured data using a human cadaver, and BER was calculated for the measured in vivo channel response along with the ideal additive white Gaussian noise and Rayleigh channel models. Linear and nonlinear adaptive equalizers, ie, decision feedback equalizer (DFE) and least mean square (LMS), were used to improve the BER performance of the in vivo radio channel. It is noticed that both the equalizers improve the BER but DFE has better BER compared to LMS and shows the 2-dB and 4-dB performance gains of DFE over the LMS at Eb/No = 12 dB and at Eb/No = 14 dB, respectively. The current findings will help guide future researchers and designers in enhancing systems performance of an ultra-wideband in vivo wireless systems.Öğe Experimental analysis of ultra wideband in vivo radio channel(Ieee, 2018) İlyas, Muhammad; Bayat, Oğuz; Abbasi, Qammer H.In this paper, we present the experimental analysis of in vivo wireless channel response on Ultra-Wideband (UWB) with the frequencies between 3.1 - 10.6 GHz. The analysis proves the location dependent based characteristics of in vivo channel. The results clearly show the highly multipath scenario. It can also be observed that the multipath effect of the channel is much higher in the denser areas, i.e. an antenna placed within the intestine area or inside the stomach. Results prove that in vivo channel is different from a conventional communication channel and therefore extensive studies need to be done to understand the channel.Öğe Location dependent channel characteristics for implantable devices(Institute of Electrical and Electronics Engineers Inc., 2020) Ilyas, Muhammad; Bayat, Oğuz; Uçan, Osman Nuri; Imran, Muhammad Ali; Abbasi, Qammer H.This paper presents an impact on an in-vivo channel with respect to the position of ex-vivo antenna placement and its location. The paper also shows how the location of the antenna is impacting the channel. Three different parts are considered for the simulations using measured data for 500 MHz bandwidth. The results in the paper present the high location dependent characteristics of the in-vivo channel in the context of changing the position of the ex-vivo antenna. These findings can help in the system design for the future of the implantable devices design to be placed inside the human body. © 2020 IEEE.Öğe Mathematical modeling of ultra wideband in vivo radio channel(Ieee-Inst Electrical Electronics Engineers Inc, 2018) İlyas, Muhammad; Uçan, Osman Nuri; Bayat, Oğuz; Yang, Xiaodong; Abbasi, Qammer H.This paper proposes a novel mathematical model for an in vivo radio channel at ultra-wideband frequencies (3.1-10.6 GHz), which can be used as a reference model for in vivo channel response without performing intensive experiments or simulations. The statistics of error prediction between experimental and proposed model is RMSE = 5.29, which show the high accuracy of the proposed model. Also, the proposed model was applied to the blind data, and the statistics of error prediction is RMSE = 7.76, which also shows a reasonable accuracy of the model. This model will save the time and cost on simulations and experiments, and will help in designing an accurate link budget calculation for a future enhanced system for ultra-wideband body-centric wireless systems.Öğe Performance enhancement of safety message communication via designing dynamic power control mechanisms in vehicular ad hoc networks(Wiley, 2021) Alabbas, Amjed Razzaq; Hassnawi, Layth A.; Ilyas, Muhammad; Pervaiz, Haris; Abbasi, Qammer H.; Bayat, OğuzIn vehicular ad hoc networks (VANETs), transmission power is a key factor in several performance measures, such as throughput, delay, and energy efficiency. Vehicle mobility in VANETs creates a highly dynamic topology that leads to a nontrivial task of maintaining connectivity due to rapid topology changes. Therefore, using fixed transmission power adversely affects VANET connectivity and leads to network performance degradation. New cross-layer power control algorithms called (BL-TPC 802.11MAC and DTPC 802.11 MAC) are designed, modeled, and evaluated in this paper. The designed algorithms can be deployed in smart cities, highway, and urban city roads. The designed algorithms improve VANET performance by adapting transmission power dynamically to improve network connectivity. The power adaptation is based on inspecting some network parameters, such as node density, network load, and media access control (MAC) queue state, and then deciding on the required power level. Obtained results indicate that the designed power control algorithm outperforms the traditional 802.11p MAC considering the number of received safety messages, network connectivity, network throughput, and the number of dropped safety messages. Consequently, improving network performance means enhancing the safety of vehicle drivers in smart cities, highway, and urban city.Öğe Ultra wideband in vivo channel modelling with respect to ex vivo antenna location(Ieee, 2019) İlyas, Muhammad; Bayat, Oğuz; İmran, Muhammad Ali; Abbasi, Qammer H.This article presents mathematical channel modeling for in-vivo communication in terms of the change in the position of the ex-vivo antenna at ultra wideband frequencies. It is shown that the location dependent characteristics are not only dependent on the in-vivo devices placed inside the human body but also the position of ex-vivo devices can impact the channel. Results are calculated using the mathematical model and curve fitting technique by calculation of the Root Mean Square Error (RMSE). The statistics of error prediction among the measured data and the proposed model is RMSE = 14.46 for the right lateral and RMSE = 11.63 for the left lateral respectively. These results will help system designer in accurate link budget calculation for designing enhance implantable devices.
