Bit Error Probability Research Articles

All-Optical format conversion from PAM4 to QPSK based on non-degenerate Phase-Sensitive amplification and pump assisted nonlinear optical loop mirror

An all-optical format conversion (AOFC) scheme from 4-ary pulse amplitude modulation (PAM4) to quadrature phase shift keying (QPSK) based on the non-degenerate phase-sensitive amplification (PSA) and the pump assisted nonlinear optical loop mirror (PA-NOLM) is proposed and numerically simulated for the first time. The input unipolar PAM4 signal with equal amplitude distance (UPAM4-A) is coupled with two input pump lights and injected into the symmetric interferometric fiber optic parameter amplifier (FOPA) to achieve the separation of the UPAM4-A and the new pump light generated at the signal frequency based on the non-degenerate PSA. When the filtered out UPAM4-A is coherent added with the new generated pump, the UPAM4-A signal to the biplolar PAM4 (BPAM4) signal. When the converted BPAM4 is sent into the PA-NOLM after adjusting its power, the BPAM4 signal could be converted into the QPSK signal. The error vector magnitude (EVM) and bit error ratio (BER) performance of the system are measured before and after AOFC with different input and receiver optical signal to noise ratio (OSNR). For the input UPAM4-A signal with an input OSNR of 27 dB, there is about 8.2 dB BER performance improvement in receiver OSNR for the final converted QPSK signal. Additionally, the proposed non-degenerate PSA configuration can be extended to realize the AOFC from one QPSK to two on–off keying (OOK) signals. The scheme can be applied in the optical gateway connecting the long-haul and the short-reach optical networks with suitable modulation formats.

Dual vector millimeter-wave signal generation based on optical carrier suppression modulation and direct detection with one photodetector.

We propose a novel, to the best of our knowledge, scheme for dual vector millimeter-wave (mm-wave) signal generation and transmission, based on optical carrier suppression (OCS) modulation, precoding, and direct detection by a single-ended photodiode (PD). At the transmitter side, two independent vector radio frequency (RF) signals with precoding, generated via digital signal processing (DSP), are used to drive an in-phase/quadrature (I/Q) modulator operating at the optical OCS modulation mode to simultaneously generate two independent frequency-doubling optical vector mm-wave signals, which can reduce the bandwidth requirement of transmitter's components and enhance spectral efficiency. With the aid of the single-ended PD and subsequent DSP at the receiver side, two independent frequency-doubling vector mm-wave signals can be separated and demodulated without data error. Based on our proposed scheme, we experimentally demonstrate the generation, transmission, and detection of 2-Gbaud 30-GHz quadrature-phase-shift-keying (QPSK) and 2-Gbaud 46-GHz QPSK signals over 10-km single-mode fiber-28 (SMF-28) and 1-m wireless transmission. The results indicate that the bit-error ratio (BER) of the dual vector mm-wave signals can each reach the hard-decision forward-error-correction (HD-FEC) threshold of 3.8 × 10-3.

Across-dimensional optical constellation de-aggregations from QAMs to PAMs in optical transparent networks

In this paper, an across-dimensional optical constellation de-aggregation scheme is proposed and verified. This de-aggregation scheme builds flexible optical connections between core and edge networks and fills the lack of the conversions between quadrature amplitude modulation (QAM) and pulse amplitude modulation (PAM) formats. 10G Baud quadrature phase shift keying/9QAM/16QAM-to-2×on off keying (OOK)/PAM3/PAM4 constellation de-aggregations are achieved. The enabled constellation manipulations contain polarization-assisted quadrature de-multiplexing and bi-directional vector moving. The key research status of QAM/PAM de-aggregations and adopted theoretical derivations are analyzed and expressed in detail. The signal spectrum, constellations, eye diagrams, transfer characteristics curves, error vector magnitudes and bit error ratios (BERs) during the de-aggregation process are calculated to measure the system performances. With the input optical signal-to-noise ratio (OSNR) of 10 dB/15 dB/20 dB, the de-aggregated OOK/PAM3/PAM4 signals show the receiver OSNR of 19.1 dB/21.9 dB/31.2 dB, respectively, at the BER of 10−3. The proposed scheme presents excellent format scalability and has potential applications in flexible all-optical connections, across-dimensional optical transmissions, and optical transparent networks.

Phase fluctuations-induced bit error ratio of deep-space optical communication systems during superior solar conjunction

Deep-space optical communication has garnered increasing attention for its high data transfer rate, wide bandwidth, and high transmission speed. However, coronal plasma turbulence severely degrades optical signals during superior solar conjunction. In this study, we introduce the models for plasma density and generalized non-Kolmogorov turbulence power spectrum. Based on these models, we derive the variance of the phase fluctuations with the assistance of the Rytov theory in the weak turbulence regime involving various variables, such as turbulence outer scale, spectral index, relative fluctuation factor, and wavelength. Subsequently, we evaluate the bit error ratio (BER) performance of the deep-space optical communication system, considering phase fluctuations and intensity scintillations, under binary phase shift keying modulation. Numerical calculations reveal that small heliocentric distance, large relative fluctuation factor and spectral index, could induce severe phase fluctuations and high BER. Fortunately, the effects of the plasma irregularities on the BER performance can be mitigated by short optical wavelength under large outer scale.

Reed–Muller Codes on BMS Channels Achieve Vanishing Bit-Error Probability for all Rates Below Capacity

This paper considers the performance of Reed-Muller (RM) codes transmitted over binary memoryless symmetric (BMS) channels under bitwise maximum-a-posteriori (bit-MAP) decoding. Its main result is that, for a fixed BMS channel, the family of binary RM codes can achieve a vanishing bit-error probability at rates approaching the channel capacity. This partially resolves a long-standing open problem that connects information theory and error-correcting codes. In contrast with the earlier result for the binary erasure channel, the new proof does not rely on hypercontractivity. Instead, it combines a nesting property of RM codes with new information inequalities relating the generalized extrinsic information transfer function and the extrinsic minimum mean-squared error.

Performance analysis of FSO communications over a generalized turbulence fading channel with pointing error

SummaryQuantitatively assessing the performance of free space optical (FSO) communication systems requires an accurate description of turbulence induced fading. However, it is well known that common irradiance distributions inaccurately model intensity tail regions. Recently, a general fading model as the product of arbitrary number of Gamma with inverse Gamma was proposed and shown to accurately predict measurements, besides containing many well‐known models as special cases. This paper is concerned with analyzing the effect of discrepancies among different fading distributions on optical system performance in terms of bit error rates and capacity. Based on the general fading model a unified analysis of the channel structure effects on FSO communications in the presence of turbulence and pointing error is presented. The outage probability is investigated for both homodyne and direct detection schemes. Closed form expressions for the average probability of bit error for intensity modulation, phase shift keying and polarization shift keying, single‐input‐single‐output systems are given and verified by Monte‐Carlo simulations. Spatial diversity is also studied through single‐input‐multiple‐output systems. Also, the ergodic capacity is derived. Comparisons between the proposed distributions and other widely used distributions are carried out and show significant differences among existing fading models. This suggests possible improvements in the spectral efficiency and error performance design of optical wireless communication systems.

Polar coded cooperative with Plotkin construction and quasi‐uniform puncturing based on MIMO antennas in half duplex wireless relay network

AbstractRecently, polar code has attracted the attention of many scholars and has been developed as a code technology in coded‐cooperative communication. We propose a polar code scheme based on Plotkin structure and quasi‐uniform punching (PC‐QUP). Then we apply the PC‐QUP to coded‐cooperative scenario and built to a new coded‐cooperative scheme, which is called PCC‐QUP scheme. The coded‐cooperative scheme based on polar code is studied on the aspects of codeword construction and performance optimization. Further, we apply the proposed schemes to space–time block coding (STBC) to explore the performance of the scheme. Monte Carlo simulation results show that the proposed cooperative PCC‐QUP‐STBC scheme can obtain a lower bit error ratio (BER) than its corresponding noncooperative scheme.

Performance Analysis of 6TiSCH Networks Using Discrete Events Simulator

The Internet of Things (IoT) empowers small devices to sense, react, and communicate, with applications ranging from smart ordinary household objects to complex industrial processes. To provide access to an increasing number of IoT devices, particularly in long-distance communication scenarios, a robust low-power wide area network (LPWAN) protocol becomes essential. A widely adopted protocol for this purpose is 6TiSCH, which builds upon the IEEE 802.15.4 standard. It introduces time-slotted channel hopping (TSCH) mode as a new medium access control (MAC) layer operating mode, in conjunction with IEEE 802.15.4g, which also defines both MAC and physical layer (PHY) layers and provides IPv6 connectivity for LPWAN. Notably, 6TiSCH has gained adoption in significant standards such as Wireless Intelligent Ubiquitous Networks (Wi-SUN). This study evaluates the scalability of 6TiSCH, with a focus on key parameters such as queue size, the maximum number of single-hop retries, and the slotframe length. Computational simulations were performed using an open-source simulator and obtained the following results: increasing the transmission queue size, along with adjusting the number of retries and slotframe length, leads to a reduction in the packet error rate (PER). Notably, the impact of the number of retries is particularly pronounced. Furthermore, the effect on latency varies based on the specific combination of these parameters as the network scales.

Age of Information for Partial Earliest Relay Aided Short Packet Status Update With Energy Harvesting

This paper focuses on the timely delivery of status updates for a multi-relay assisted energy harvesting (EH) Internet of Things system with short packet communications (SPC), where an EH-powered source transmits status updates to a destination with the aid of multiple EH-powered relays. To improve the energy efficiency and information freshness, an earliest-ℓ partial relay selection scheme is proposed, in which the earliest ℓ relays that successfully receive the status update from the source will be selected to forward the status update to the destination, and the selection combining (SC) and maximal-ratio combining (MRC) schemes are used at the destination. Firstly, we investigate the update packet delivery schemes of source-relay (S-R) and relay-destination (R-D) links, and present the packet error probabilities under the SC and MRC schemes based on SPC theory. Secondly, after characterizing the full charge time durations of both the source and relay, we investigate the statistical description of the number of the packet transmission attempts from the source to relay as well as the one from the relay to destination by using order statistics. With the analysis of the evolution of the instantaneous age of information (AoI), the expression for average AoI is derived. Finally, we investigate the average AoI minimization, which is formulated as a coupled triplet problem of the packet lengths at the source and relays and the value of ℓ. To overcome the coupling, we present the convexity approximation of the average AoI as well as the concise proof. Then, an efficient gradient-based two-step optimal search algorithm is proposed to solve the optimization problem, which searches the local optimal packet lengths for S-R and R-D links by iteratively updating the value of ℓ until the global optimal objective parameters are found. Numerical analyses give the effect of the key parameters on the average AoI, and the comparison demonstrates that the proposed gradient-based method converges quickly than the conventional greedy search method.

Improved Performance of 5G Based Software Defined Networks

With the growth of processed data for wireless networks and the establishment of new applications and services, mobile operators keep searching for solutions to deal with the issues raised by nextgeneration networks (NGN). The fifth generation (5G) mobile networks, for example, should enhance their performance without consuming a lot of energy. For these reasons, software-defined networks (SDN) appear to be the promising technology that will make achieving the architectural agility required for the upcoming 5G mobile networks easier. SDN is a clever solution for providing innovation and enforcing the primary drivers in 5G mobile networks, such as flexibility, dependability, service-oriented management, and cost reduction through the control and management of the 5G core network. In this paper, the integration of SDN and multiple controllers with the 5G core network is investigated to determine how these two technologies can affect mobile IP network performance. An energy model suitable for the proposed network architecture has been developed. A widely used Diamond network is being considered for the core network. Open-Flow controllers were used to improve the routing performance by considering load balancing of IP traffic. According to such a model, reduced energy consumption is experienced with SDN. The addition of an SDN controller results in a 11% reduction in consumed energy. The results also show that the use of SDN and multi-controller with NGN can improve the performance further. Using SDN reduced the average delay of the network by 14%. A great reduction in packet error rate (PER) is also achieved when SDN is used.

A Novel Fuzzy Based Beluga Whale Optimization for Enhancing Link Stability and Optimal Route discovery in MANET

The networking field plays a major role and developed significantly over the past decades. The identification of best route in Mobile Ad hoc Networks (MANETs) is a complex problem in the multipath routing method. Besides, multipath discovery is regarded as the other difficult task for improving the existence of the network. Through optimal route discovery, the routing protocol considers several parameters like link failures, topological variations, obstacles, and extended power. In this paper, based on optimal route discovery, a novel Fuzzy Beluga Whale Optimization (FBWO) is proposed for presenting effective routing and enhanced link stability. The Beluga Whale Optimization (BWO) algorithm determines multiple routes in the network for communicating data packets to their destination. However, the discovered routes may be susceptible to link failures due to the complete energy exhaustion of nodes during continuous data transmission. Therefore, the stability of links is assured by evaluating link stability indicators namely probabilistic link reliable time, link expiration time, residual battery power, link received signal strength, and link packet error rate. Moreover, optimal routes in the network are established using a fuzzy rule system by adopting fuzzy rules. Thus, the proposed FBWO approach maximizes the overall performance of the network by establishing optimal routes to broadcast packets along with enhanced link stability and signal strength. The experimental results manifest the FBWO model and achieve superior accuracy in terms of all measures than other existing methods.

Hybrid Quantum Key Distribution Protocol with Chaotic System for Securing Data Transmission

This research proposes a combination of Quantum Key Distribution (QKD) based on the BB84 protocol with Improved Logistic Map (ILM) to improve data transmission security. This method integrates quantum key formation from BB84 with ILM encryption. This combination creates an additional layer of security, where by default, the operation on BB84 is only XOR-substitution, with the addition of ILM creating a permutation operation on quantum keys. Experiments are measured with several quantum measurements such as Quantum Bit Error Rate (QBER), Polarization Error Rate (PER), Quantum Fidelity (QF), Eavesdropping Detection (ED), and Entanglement-based detection (EDB), as well as classical cryptographic analysis such as Bit Error Ratio (BER), Entropy, Histogram Analysis, and Normalized Pixel Change Rate (NPCR) and Unified Average Changing Intensity (UACI). As a result, the proposed method obtained satisfactory results, especially perfect QF and BER, and EBD, which reached 0.999.

Emission rate optimization in diffusion-based molecular communication among mobile bacteria

In quorum sensing (QS), bacteria exchange information by using molecular signals to work together. In this paper, we study diffusion-based molecular communication with the QS mechanism between the transmitter node and receiver node which are composed of a population of mobile bacteria in a cluster, respectively. The expression of average bit error probability (BEP) at a receiver bacterium is derived. Furthermore, we use the projected gradient descent (PGD) algorithm to solve the optimization problem whose objective is to minimize the average BEP under emission rate constraints which require that the emission rate of each transmitter bacterium has lower and upper bounds. Finally, the numerical results show the PGD algorithm has good convergence behaviors and it is more efficient in finding the optimal emission rate with fewer iterations than genetic algorithm. The obtained results are expected to provide guidance in designing QS-based molecular communication system with lower average BEP.

Diffusion-assisted quantum noise stream cipher for physical layer security in UFMC

Universal filtered multicarrier (UFMC) is a promising multicarrier technologies due to its ability to suppress inter symbol interference, increase frequency band utilization and provide flexible adaptation. However, it is vulnerable to illegal eavesdropping in the point-to-multipoint access transmission. Quantum noise stream cipher (QNSC), a classical physical layer encryption scheme, is inherent matched with the UFMC system. However, its security mainly depends on the length of the basis states, which is limited by the performance of commercial high-speed digital-to-analog converters (DACs). In this work, we propose a diffusion-assisted quantum noise stream cipher (DA-QNSC) scheme to enhance the security. Here, we introduce artificial noise generated by hyperchaotic system to pseudo expand the distribution of quantum noise, which will make it more difficult for eavesdroppers to crack plaintext information violently. We experimentally demonstrate the encrypted 16/4096-QAM, 16/16384-QAM, 16/65536-QAM DA-QNSC signals over 30-km standard single mode fiber (SSMF) transmission. Compared to the conventional QNSC systems, the proposed method achieves a 3.6 times improvement in the security with the same DAC resolution and has negligible impact on bit error ratio (BER) performance. For the 16/65536-QAM signal, the number of masked symbols (NMS) are increased from 910 to 3270.

Fragmentation of data packets in wireless sensor network with variable temperature and channel conditions

This study formalizes and solves the problem of minimizing the energy dissipated by a node in order to successfully transmit the initial data amount during one round of communication over a wireless channel affected by Rice fading under varying temperature conditions. In this work, the models for the temperature dependence of the parameters in an incoherent frequency shift key (FSK) demodulator are presented and investigated for the first time, taking into account both the frequency separation and the synchronization type of the clock generator. The studied orthogonality coefficients of FSK signals represent internal parameters in the proposed model of the incoherent Rice wireless channel. This model allows the analytical relationship between the bit error probability (BEP) and node heating temperature, signal fading depth in the channel (Rician K-factor), and signal-to-noise ratio (SNR) to be established.Since it is necessary to retransmit the entire data packet when an erroneous bit is detected in a communication system that uses an automatic repeat request, at high BEP values, it is recommended to fragment packets in order to improve the energy efficiency of the nodes. By using the developed models for calculating energy losses during the communication round, it was determined that optimal fragmentation options (OFO) for data packets can be identified within specific ranges of temperature and Rician K-factor, which includes the overhead costs for packeting and retransmission. As a result, OFO matrices of packets in the "temperature – K-factor" (t0–K) coordinate system were obtained for minimizing the energy loss of nodes at different SNR values. In our example of using TI CC2500 node transceivers for 90-day monitoring of corn vegetation, the t0K-Frag algorithm reduced node energy losses by a factor of K = 3.3 compared to the case of transmitting an unfragmented packet of initial length.

BEP evaluation of 5G LDPC codes in a pre-amplified optical PPM receiver

We present results for the performance of a pre-amplified optical pulse-position modulation (PPM) receiver that utilizes the low-density parity-check (LDPC) correction codes of the 5G standard. The code construction is suitable for correcting burst errors that are introduced by PPM. Simulation results show that the LDPC codes can provide a very significant real gain, provided that the code rate is chosen appropriately. We find that the code rates that minimize the bit-error-probabilities (BEPs) of the system range between 2/3 and 22/26, with higher code rates being required in receivers that operate under increased optical noise. It is also shown that a comparable real gain is obtained for both the sum–product and min-sum decoders, while the power penalty of the latter one is only limited to 0.2 dB, when the aforementioned code rates are utilized.

Помехоустойчивость многопользовательских систем MIMO при неидеальной оценке канала и других искажениях

The technology of multi-antenna MIMO (Multiple Input Multiple Output) systems is actively used in modern wireless communication systems. MIMO can enhance the performance of wireless data transmission systems, but their effectiveness depends on the transmission conditions. Ideal conditions are represented as a channel with a large number of possible signal propagation paths and an error-free estimation of its parameters. The estimation error significantly affects the performance of the beamforming algorithms used to mitigate inter-user interference in multi-user MIMO (MU-MIMO) systems. Spatial correlation of the channel results in a decrease in the number of independent information transmission streams. These factors can significantly reduce the performance of multi- antenna systems. For this reason, operating MIMO communication systems under non-ideal conditions is a topical issue. The paper examines the performance of various beamforming algorithms in such conditions. It describes the communication systems with MIMO, beamforming algorithms, and distorting effects. The paper includes a developed simulation model of the communication channel with MU-MIMO accounting for a variety of distorting factors. The results demonstrate the bit-error probability dependences for different simulation scenarios.

The Environmental Impacts of Radio Frequency and Power Line Communication for Advanced Metering Infrastructures in Smart Grids.

In the neighborhood area network (NAN), the advanced metering infrastructure (AMI) enables a bidirectional connection between the smart meter (SM) and the data concentrator (DC). Sensors, such as smart meter nodes or environmental sensor nodes, play a crucial role in measuring and transmitting data to central units for advanced monitoring, management, and analysis of energy consumption. Wired and wireless communication technologies are used to implement the AMI-NAN. This paper delves into a novel approach for optimizing the choice of communication medium, air for radio frequency (RF) or power lines for power line communication (PLC), between the SM and DC in the context of the AMI-NAN. The authors methodically select the specific technologies, RF and NB-PLC (narrowband power line communication), and meticulously characterize their attributes. Then, a comparative analysis spanning rural, urban, and industrial settings is conducted to evaluate the proposed method. The overall reliability performance of the AMI-NAN system requires a packet error rate (PER) lower than 10%. To this end, an efficient approach is introduced to assess and enhance the reliability of NB-PLC and RF for AMI-NAN applications. Simulation results demonstrate that wireless communication is the optimal choice for the rural scenario, especially for a signal-to-noise ratio (SNR) lower than 25 dB. However, in urban environments characterized by higher SNR values and moderately dense networks, NB-PLC gains prominence. In denser networks, it outperforms wireless communication, exhibiting a remarkable 10 dB gain for a bit error rate (BER) of 10-3. Moreover, in industrial zones characterized by intricate network topologies and non-linear loads, the power line channel emerges as the optimal choice for data transmission.

Linear/Non-Linear Energy Harvesting Models via Multi-Antenna Relay Cooperation in V2V Communications

Vehicle-to-vehicle (V2V) communications is a part of next-generation wireless networks to create smart cities with the connectivity of intelligent transportation systems. Besides, green communications is considered in V2V communication systems for energy sustainability and carbon neutrality. In this scope, radio-frequency (RF) energy harvesting (EH) provides a battery-free energy source as a solution for the future of V2V communications. Herein, the employment of RF-EH in V2V communications is considered where the bit error probability (BEP) of a dual-hop decode-and-forward relaying system is obtained depending on the utilization of antennas at the relay. The multiple antenna power-constraint relay harvests its power by applying dedicated antenna (DA)/power splitting (PS) EH modes and linear (L)/nonlinear (NL) EH models. Moreover, the links between nodes are exposed to double-Rayleigh fading. Finally, the performance of different system parameters is compared using theoretical derivations of BEP. The results provide a comprehensive analysis of the proposed system considering PS/DA-EH modes and L/NL-EH models, as well as deterministic/uniformly distributed placement of nodes. It is observed that PS-EH outperforms DA-EH assuming a placement of an equal number of antennas and distances. Moreover, optimal performance of PS/DA-EH is achieved by allocating more power and increasing the number of antennas for EH, respectively.

Integrated Optical Sensing and Communication (IOSAC) System Based on Hybrid‐Waveguide Structures

AbstractAdvanced silicon photonic technologies enable integrated optical sensing and communication (IOSAC) in real time for the emerging application requirements of simultaneous sensing and communication for next‐generation networks. Herein, an IOSAC system is proposed and demonstrated on the silicon nitride (Si3N4) photonics platform. The IOSAC devices leveraging microring resonators excel in real‐time monitoring of analyte fluctuations and efficiently transmit this data to the terminal, positioning them as viable alternatives to bulk optics in applications that demand both high precision and speed. By directly integrating Si3N4 ring resonators with optical communication networks, simultaneous sensing and optical communication are demonstrated by an optical signal transmission experimental system using especially filtering amplified spontaneous emission spectra. The refractive index (RI) sensing ring with a sensitivity of 172 nm RIU−1, a figure of merit (FOM) of 1220, and a detection limit (DL) of 8.2 × 10−6 RIU is demonstrated. Simultaneously, the 1.25 Gbps optical on‐off‐keying (OOK) signal is transmitted at the concentration of different NaCl solutions, indicating the bit‐error‐ratio (BER) decreases with the increase in concentration. The novel IOSAC technology shows the potential to realize high‐performance simultaneous biosensing and communication in real time and further accelerate the development of IoT and 6G networks.