scholarly journals Low-Complexity Channel Codes for Reliable Molecular Communication via Diffusion

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 41
Author(s):  
Sofia Figueiredo ◽  
Nuno Souto ◽  
Francisco Cercas
Keyword(s):  
Channel Coding ◽  
Communication Systems ◽  
Communication Channel ◽  
Low Complexity ◽  
Proof Of Concept ◽  
Test Bed ◽  
Experimental Proof ◽  
Channel Codes ◽  
Processing Power ◽  
Very High

It is envisioned that healthcare systems of the future will be revolutionized with the development and integration of body-centric networks into future generations of communication systems, giving rise to the so-called “Internet of Bio-nano things”. Molecular communications (MC) emerge as the most promising way of transmitting information for in-body communications. One of the biggest challenges is how to minimize the effects of environmental noise and reduce the inter-symbol interference (ISI) which in an MC via diffusion scenario can be very high. To address this problem, channel coding is one of the most promising techniques. In this paper, we study the effects of different channel codes integrated into MC systems. We provide a study of Tomlinson, Cercas, Hughes (TCH) codes as a new attractive approach for the MC environment due to the codeword properties which enable simplified detection. Simulation results show that TCH codes are more effective for these scenarios when compared to other existing alternatives, without introducing too much complexity or processing power into the system. Furthermore, an experimental proof-of-concept macroscale test bed is described, which uses pH as the information carrier, and which demonstrates that the proposed TCH codes can improve the reliability in this type of communication channel.

scholarly journals Low complexity Turbo synchronization without initial carrier synchronization

2010 ◽  
Vol 8 ◽  
pp. 123-128 ◽  
Author(s):  
U. Wasenmüller ◽  
C. Gimmler ◽  
N. Wehn
Keyword(s):  
Turbo Codes ◽  
Channel Coding ◽  
Communication Systems ◽  
Low Complexity ◽  
Wireless Data ◽  
Carrier Synchronization ◽  
Wireless Data Transmission ◽  
Xilinx Fpga ◽  
Digital Communication Systems ◽  
Turbo Synchronization

Abstract. Wireless data transmission results in frequency and phase offsets of the signal in the receiver. In addition the received symbols are corrupted by noise. Therefore synchronization and channel coding are vital parts of each receiver in digital communication systems. By combining the phase and frequency synchronization with an advanced iterative channel decoder (inner loop) like turbo codes in an iterative way (outer loop), the communications performance can be increased. This principal is referred to as turbo synchronization. For turbo synchronization an initial estimate of phase and frequency offset is required. In this paper we study the case, where the initial carrier synchronization is omitted and an approach with trial frequencies is chosen. We present novel techniques to minimize the number of trial frequencies to be processed. The communications performance and effort of our method is demonstrated. Furthermore the implementation complexity of the whole system is shown on a Xilinx FPGA.

scholarly journals Performance and Complexity Evaluation of Iterative Receiver for Coded MIMO-OFDM Systems

2016 ◽  
Vol 2016 ◽  
pp. 1-22 ◽  
Author(s):  
Rida El Chall ◽  
Fabienne Nouvel ◽  
Maryline Hélard ◽  
Ming Liu
Keyword(s):  
Channel Coding ◽  
Communication Systems ◽  
Forward Error Correction ◽  
Multiple Input Multiple Output ◽  
Low Complexity ◽  
Ofdm Systems ◽  
Mimo Detection ◽  
Iterative Receiver ◽  
Ldpc Decoder ◽  
Trade Offs

Multiple-input multiple-output (MIMO) technology in combination with channel coding technique is a promising solution for reliable high data rate transmission in future wireless communication systems. However, these technologies pose significant challenges for the design of an iterative receiver. In this paper, an efficient receiver combining soft-input soft-output (SISO) detection based on low-complexity K-Best (LC-K-Best) decoder with various forward error correction codes, namely, LTE turbo decoder and LDPC decoder, is investigated. We first investigate the convergence behaviors of the iterative MIMO receivers to determine the required inner and outer iterations. Consequently, the performance of LC-K-Best based receiver is evaluated in various LTE channel environments and compared with other MIMO detection schemes. Moreover, the computational complexity of the iterative receiver with different channel coding techniques is evaluated and compared with different modulation orders and coding rates. Simulation results show that LC-K-Best based receiver achieves satisfactory performance-complexity trade-offs.

Efficient Receiver Implementation for Mobile Applications

2009 ◽  
pp. 271-298
Author(s):  
Costas Chaikalis ◽  
Felip Riera-Palou
Keyword(s):  
Communication Systems ◽  
Low Complexity ◽  
Wireless Communication Systems ◽  
Channel Decoding ◽  
High Data ◽  
Data Rates ◽  
Channel Effects ◽  
Environment Simulation ◽  
Very High

Modern and future wireless communication systems such as UMTS and beyond 3G systems (B3G) are expected to support very high data rates to/from mobile users. This poses important challenges on the handset design as they should be able to attain an acceptable operating bit error rate (BER) while employing a limited set of resources (i.e. low complexity, low power) and often, with tight processing delay constraints. In this chapter we study how channel decoding and equalisation, two widely used mechanisms to combat the deleterious channel effects, can be made adaptable in accordance to the instantaneous operating environment. Simulation results are given demonstrating how receiver reconfigurability is a promising method to achieve complexity/delay efficient receivers while maintaining prescribed quality of service (QoS) constraints.

scholarly journals Low-complexity beam-domain channel estimation and power allocation in hybrid architecture massive MIMO systems

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Xiao Chen ◽  
Zaichen Zhang ◽  
Liang Wu ◽  
Jian Dang
Keyword(s):  
Channel Estimation ◽  
Power Allocation ◽  
Spectral Efficiency ◽  
Communication Systems ◽  
Mimo Systems ◽  
Beam Steering ◽  
Estimation Method ◽  
Low Complexity ◽  
Estimation Accuracy ◽  
Hybrid Architecture

Abstract In this journal, we investigate the beam-domain channel estimation and power allocation in hybrid architecture massive multiple-input and multiple-output (MIMO) communication systems. First, we propose a low-complexity channel estimation method, which utilizes the beam steering vectors achieved from the direction-of-arrival (DOA) estimation and beam gains estimated by low-overhead pilots. Based on the estimated beam information, a purely analog precoding strategy is also designed. Then, the optimal power allocation among multiple beams is derived to maximize spectral efficiency. Finally, simulation results show that the proposed schemes can achieve high channel estimation accuracy and spectral efficiency.

scholarly journals Directed Data-Processing Inequalities for Systems with Feedback

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 533
Author(s):  
Milan S. Derpich ◽  
Jan Østergaard
Keyword(s):  
Mutual Information ◽  
Data Processing ◽  
Channel Coding ◽  
Communication Channel ◽  
Closed Loop ◽  
Transmission Rate ◽  
Information Rate ◽  
Random Input ◽  
Directed Information ◽  
Stochastic Mapping

We present novel data-processing inequalities relating the mutual information and the directed information in systems with feedback. The internal deterministic blocks within such systems are restricted only to be causal mappings, but are allowed to be non-linear and time varying, and randomized by their own external random input, can yield any stochastic mapping. These randomized blocks can for example represent source encoders, decoders, or even communication channels. Moreover, the involved signals can be arbitrarily distributed. Our first main result relates mutual and directed information and can be interpreted as a law of conservation of information flow. Our second main result is a pair of data-processing inequalities (one the conditional version of the other) between nested pairs of random sequences entirely within the closed loop. Our third main result introduces and characterizes the notion of in-the-loop (ITL) transmission rate for channel coding scenarios in which the messages are internal to the loop. Interestingly, in this case the conventional notions of transmission rate associated with the entropy of the messages and of channel capacity based on maximizing the mutual information between the messages and the output turn out to be inadequate. Instead, as we show, the ITL transmission rate is the unique notion of rate for which a channel code attains zero error probability if and only if such an ITL rate does not exceed the corresponding directed information rate from messages to decoded messages. We apply our data-processing inequalities to show that the supremum of achievable (in the usual channel coding sense) ITL transmission rates is upper bounded by the supremum of the directed information rate across the communication channel. Moreover, we present an example in which this upper bound is attained. Finally, we further illustrate the applicability of our results by discussing how they make possible the generalization of two fundamental inequalities known in networked control literature.

scholarly journals Car2Car Communication Using a Modulated Backscatter and Automotive FMCW Radar

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3656
Author(s):  
Antonio Lazaro ◽  
Marc Lazaro ◽  
Ramon Villarino ◽  
David Girbau ◽  
Pedro de Paco
Keyword(s):  
Power Supply ◽  
Communication Systems ◽  
Microwave Frequency ◽  
Proof Of Concept ◽  
Driver Assistance ◽  
Switching Rate ◽  
Fmcw Radar ◽  
Time Signals ◽  
Video Sensors ◽  
24 Ghz

This work proposes the use of a modulated tag for direct communication between two vehicles using as a carrier the wave emitted by an FMCW radar installed in the vehicle for advanced driver assistance. The system allows for real-time signals detection and classification, such as stop signal, turn signals and emergency lights, adding redundancy to computer video sensors and without incorporating additional communication systems. A proof-of-concept tag has been designed at the microwave frequency of 24 GHz, consisting of an amplifier connected between receiving and transmitting antennas. The modulation is performed by switching the power supply of the amplifier. The tag is installed on the rear of the car and it answers when it is illuminated by the radar by modulating the backscattered field. The information is encoded in the modulation switching rate used. Simulated and experimental results are given showing the feasibility of the proposed solution.

Joint low-complexity equalization and CFO estimation and compensation for UWA-OFDM communication systems

2020 ◽  
Vol 33 (3) ◽  
pp. e3972 ◽  
Author(s):  
Khaled Ramadan ◽  
Khalil F. Ramadan ◽  
Ahmed S. Fiky ◽  
Hasna Alam ◽  
Moawad I. Dessouky ◽  
...  
Keyword(s):  
Communication Systems ◽  
Low Complexity

FULL-RATE AND LOW-COMPLEXITY SPACE-TIME BLOCK CODING CONCATENATED WITH CHANNEL CODES

2007 ◽  
Vol 06 (01) ◽  
pp. 5-14 ◽  
Author(s):  
XIANGBIN YU ◽  
GUANGGUO BI
Keyword(s):  
Channel Coding ◽  
Turbo Code ◽  
Multiple Antennas ◽  
Low Complexity ◽  
Space Time ◽  
System Throughput ◽  
Time Block ◽  
Coding Schemes ◽  
Full Diversity ◽  
Full Rate

Space-time block (STB) coding has been an effective transmit diversity technique for combating fading recently. In this paper, a full-rate and low-complexity STB coding scheme with complex orthogonal design for multiple antennas is proposed, and turbo code is employed as channel coding to improve the proposed code scheme performance further. Compared with full-diversity multiple antennas STB coding schemes, the proposed scheme can implement full data rate, partial diversity and a smaller complexity, and has more spatial redundancy information. Moreover, using the proposed scheme can form efficient spatial interleaving, thus performance loss due to partial diversity is effectively compensated by the concatenation of turbo coding. Simulation results show that on the condition of the same system throughput and concatenation of turbo code, the proposed scheme has lower bit error rate (BER) than those low-rate and full-diversity multiple antennas STB coding schemes.

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