Mikio Hasegawa

Tokyo University of Science | TUS · Department of Electrical Engineering

Ongoing research endeavors are exploring the potential of artificial intelligence to enhance the efficiency of wireless communication systems. Nevertheless, complex computational mechanisms, such as those inherent in neural networks, are not optimally suited for applications where the reduction of computational intricacy is of paramount importance....

A Piggyback network, which is a store-carry-forward network organized by working mobilities of delivery trucks and serving robots, realizes a large-scale data distribution platform. However, when the working mobilities participate in the Piggyback network, the data carrying and forwarding tasks influence their original tasks, resulting in additiona...

The effectiveness of laser chaos decision-makers in facilitating ultrafast decision-making makes it possible for a real-time process of channel allocation scheme for the non-orthogonal multiple access (NOMA) technology in the next generation of wireless communications. However, managing the increasing number of users is challenging as the complexit...

Cognitive radio networks' evolution hinges significantly on the use of automatic modulation classification (AMC). However, existing research reveals limitations in attaining high AMC accuracy due to ineffective feature extraction from signals. To counter this, we propose a vision-centric approach employing diverse kernel sizes to augment signal ext...

Long-Range (LoRa) devices have been deployed in many Internet of Things (IoT) applications due to their ability to communicate over long distances with low power consumption. The scalability and communication performance of the LoRa systems are highly dependent on the spreading factor (SF) and channel allocations. In particular, it is important to...

The design of Media Access Control (MAC) protocols for the IoT has become important owing to the rapid growth in the number of IoT devices. To realize efficient and large-scale wireless networks, autonomous distributed time division multiple access (TDMA) has been studied in previous research. We previously proposed a distributed TDMA suitable for...

Non-terrestrial networks, composed of ground, air, and satellite communications, are considered one of the key components for the Beyond 5G/6G, and optical satellite communication is a fundamental technology to enable high-capacity communications. It is affected by interruptions of optical communications due to clouds on the communication link. A s...

LoRaWAN, one of Low-Power-Wide-Area (LPWA), has been deployed in many IoT applications due to its ability to communicate over long distances and low power consumption. However, the scalability and communication performance of LoRaWAN is highly dependent on Spreading Factor (SF) and Channel (CH) allocation. In particular, it is important to configur...

The evolving Internet of Things (IoT) promisingly improves the quality of life and transforms many industries. However, the IoT application challenges the wireless networks since the resource-constrained IoT devices typically need to send data to the cloud or edge server. Therefore, it is necessary to introduce an intermediate device between IoT de...

Asynchronous Pulse Code Multiple Access (APCMA) is a pulse-based communication system for massive IoT. It enables high-density communication because it can decode messages with a high probability even if they collide. We evaluate the performance of APCMA with Chirp Spread Spectrum-modulated pulses (CSS-APCMA) by comparing it with On-Off Keying APCM...

Fully pairing all elements of a set while attempting to maximize the total benefit is a combinatorically difficult problem. Such pairing problems naturally appear in various situations in science, technology, economics, and other fields. In our previous study, we proposed an efficient method to infer the underlying compatibilities among the entitie...

The Piggyback Network has been proposed as one of the technologies to enable Beyond 5G society. The Piggyback Network provides a high-speed data transfer system with frequency radio, such as millimeter-wave (mmW) links and Store-Carry-Forward (SCF) based communication among multiple autonomous mobilities. Communicating with mmW enables high-speed a...

Non-orthogonal multiple access (NOMA) technique is important for achieving a high data rate in next-generation wireless communications. A key challenge to fully utilizing the effectiveness of the NOMA technique is the optimization of the resource allocation (RA), e.g., channel and power. However, this RA optimization problem is NP-hard, and obtaini...

With the increasing requirements for location-based services for Internet of things (IoT) applications, ultrawideband (UWB) technology provides accurate indoor positioning capabilities. However, indoor environments contain various obstacles leading to significant signal propagation effects. This results in errors in the time-of-arrival-based UWB po...

Non-orthogonal multiple access (NOMA) technique is important for achieving a high data rate in next-generation wireless communications. A key challenge to fully utilizing the effectiveness of the NOMA technique is the optimization of the resource allocation (RA), e.g., channel and power. However, this RA optimization problem is NP-hard, and obtaini...

Fully pairing all elements of a set while attempting to maximize the total benefit is a combinatorically difficult problem. Such pairing problems naturally appear in various situations in science, technology, economics, and other fields. In our previous study, we proposed an efficient method to infer the underlying compatibilities among the entitie...

Photonic accelerators have been intensively studied to provide enhanced information processing capability to benefit from the unique attributes of physical processes. Recently, it has been reported that chaotically oscillating ultrafast time series from a laser, called laser chaos, provides the ability to solve multi-armed bandit (MAB) problems or...

The number of IoT devices is predicted to reach 125 billion by 2023. The growth of IoT devices will intensify the collisions between devices, degrading communication performance. Selecting appropriate transmission parameters, such as channel and spreading factor (SF), can effectively reduce the collisions between long-range (LoRa) devices. However,...

In recent times, the number of Internet of Things devices has increased considerably. Numerous Internet of Things devices generate enormous traffic, thereby causing network congestion and packet loss. To address network congestion in massive Internet of Things systems, an efficient channel allocation method is necessary. Although some channel alloc...

Generating paired sequences with maximal compatibility from a given set is one of the most important challenges in various applications, including information and communication technologies. However, the number of possible pairings explodes in a double factorial order as a function of the number of entities, manifesting the difficulties of finding...

In next-generation wireless communication systems, non-orthogonal multiple access (NOMA) has been recognized as essential technology for improving the spectrum efficiency. NOMA allows multiple users transmit data using the same resource block simultaneously with proper user pairing. Most of the pairing schemes, however, require prior information, s...

To realize massive IoT environments, we proposed Asynchronous Pulse Code Multiple Access (APCMA). APCMA encodes information as intervals between pulses. The sparse signal of APCMA allows a large number of devices to share the limited radio resources. In this paper, we evaluate APCMA with a variety of setting and find that code division of two and d...

Photonic accelerators have been intensively studied to provide enhanced information processing capability to benefit from the unique attributes of physical processes. Recently, it has been reported that chaotically oscillating ultrafast time series from a laser, called laser chaos, provides the ability to solve multi-armed bandit (MAB) problems or...

Generating paired sequences with maximal compatibility from a given set is one of the most important challenges in various applications, including information and communication technologies. However, the number of possible pairings explodes in a double factorial order as a function of the number of entities, manifesting the difficulties of finding...

While the Internet of Things (IoT) is usually envisioned to support powerful functionality, like in self-driving cars, there is also increasing interest in simpler IoT applications that can be employed on massive scales at high densities, like in data gathering at meetings with large audiences. The latter vision requires low-cost devices consuming...

Non-Orthogonal Multiple Access is one of the most important technologies in 5G and Beyond 5G wireless communications, which improve system performance by power domain multiplexing. In realizing Non-Orthogonal Multiple Access, the pairing of multiple users is necessary where efficient principles are highly demanded in dynamically changing electromag...

Laser chaos decision-maker has been demonstrated to enable ultrahigh-speed decision-making in solving multi-armed bandit (MAB) problems in the GHz order. In addition to recent intensive studies of photonic information processing devices and systems, the pursuit of novel applications is important, which is also demanded from future technologies, inc...

High-bandwidth irregular oscillations caused by optical time-delayed feedback subjected to the laser cavity, known as laser chaos, have been investigated for various engineering applications. Recently, a fast decision-making algorithm for a multi-arm bandit problem by utilizing laser chaos time series has been demonstrated. Furthermore, the arms or...

In recent years, the demand for new applications using various Internet of Things (IoT) devices has led to an increase in the number of devices connected to wireless networks. However, owing to the limitation of available frequency resources for IoT devices, the degradation of the communication quality caused by channel congestion is a practical pr...

Since the beginning of the COVID-19 pandemic, the demand for unmanned aerial vehicles (UAVs) has surged owing to an increasing requirement of remote, noncontact, and technologically advanced interactions. However, with the increased demand for drones across a wide range of fields, their malicious use has also increased. Therefore, an anti-UAV syste...

We propose a simple channel-allocation method based on tug-of-war (TOW) dynamics, combined with the time scheduling based on nonlinear oscillator synchronization to efficiently use of the space (channel) and time resources in wireless communications. This study demonstrates that synchronization groups, where each node selects a different channel, a...

Recent localization methods for wireless networks cannot be applied to dynamic networks with unknown topology. To solve this problem, we propose a localization method based on partial correlation analysis in this paper. We evaluate our proposed localization method in terms of accuracy, which shows that our proposed method can achieve high accuracy...

We propose a simple channel-allocation method based on tug-of-war (TOW) dynamics, combined with the time scheduling based on nonlinear oscillator synchronization to efficiently use of the space (channel) and time resources in wireless communications. This study demonstrates that synchronization groups, where each node selects a different channel, a...

For the realization of an Internet of Things (IoT) with high densities of devices it is necessary that wireless communication protocols are developed that offer (1) low energy consumption, (2) simplicity of encoding and decoding, (3) an asynchronous mode of communication, and (4) an effective but simple method to deal with interference between tran...

This letter reports on an ultra-fast and accurate channel assignment approach using a coherent Ising machine (CIM) for dense wireless LAN (WLAN) systems. CIM is a laser-based high-speed hardware approach for solving Ising problems using optoelectronic features. We formulate the total-throughput maximization problem for large-scale centralized WLAN...

For Massive IoT systems, various Low Power Wide Area (LPWA) systems have been developed and deployed, i.e., LoRa, SigFox, etc. In this paper, to avoid destructive collisions when multiple IoT LoRa signals simultaneously received in the same channel, we propose a Successive Interference Cancellation (SIC) based collision avoidance mechanism by acces...

The laser chaos decision maker has been demonstrated to enable ultra-high-speed solutions of multiarmed bandit problems or decision-making in the GHz order. However, the underlying mechanisms are not well understood. In this paper, we analyze the chaotic dynamics inherent in experimentally observed laser chaos time series via surrogate data and fur...

By exploiting ultrafast and irregular time series generated by lasers with delayed feedback, we have previously demonstrated a scalable algorithm to solve multi-armed bandit (MAB) problems utilizing the time-division multiplexing of laser chaos time series. Although the algorithm detects the arm with the highest reward expectation, the correct reco...

It is necessary to develop an efficient channel selection method with low power consumption to achieve high communication quality for distributed massive IoT system. To this end, Ma et al. [1] proposed an autonomous distributed channel selection method based on the Tug-of-War (ToW) dynamics. The ToW-based method can achieve equivalent performance t...

An Internet of Things (IoT) employing resource-restricted (e.g., battery-limited) IoT devices at high densities will require an effective multiplexing protocol that can be implemented with low energy consumption, while being able to effectively avoid collisions between the transmissions from multiple IoT devices. Asynchronous Pulse-Code Multiple Ac...

Data-driven and feedback cycle-based approaches are necessary to optimize the performance of modern complex wireless communication systems. Machine learning technologies can provide solutions for these requirements. This study shows a comprehensive framework of optimizing wireless communication systems and proposes two optimal decision schemes that...

Asynchronous Pulse-Code Multiple Access (APCMA) has been proposed as a brain-inspired communication protocol based on pulse-like signals (Peper et al, The Brain & Networks, 2018). Encoding data as intervals between pulses, APCMA allows multiple transmitters to transmit pulse trains at arbitrary times. While this typically causes collisions in conve...

Recently, new optimization machines based on non-silicon physical systems, such as quantum annealing machines, have been developed, and their commercialization has been started. These machines solve the problems by searching the state of the Ising spins, which minimizes the Ising Hamiltonian. Such a property of minimization of the Ising Hamiltonian...

By exploiting ultrafast and irregular time series generated by lasers with delayed feedback, we have previously demonstrated a scalable algorithm to solve multi-armed bandit (MAB) problems utilizing the time-division multiplexing of laser chaos time series. Although the algorithm detects the arm with the highest reward expectation, the correct reco...

Dynamic channel selection is among the most important wireless communication elements in dynamically changing electromagnetic environments wherein, a user can experience improved communication quality by choosing a better channel. Multi-armed bandit (MAB) algorithms are a promising approach that resolve the trade-off between channel exploration and...

Mobile wireless communication demand has increased rapidly in recent years, and advanced mobile devices such as smartphones have been widely deployed. Those devices are generally capable of connecting various wireless networks such as cellular networks and wireless LANs. Due to the software and hardware constraint of mobile devices, it is necessary...

A power packet dispatching system and power packet routers with the power storages have been developed. The system is expected to reduce the number of wires, to provide energy on demand and to be applied to various system working with battery such as electric vehicles, robots and so on. In the previous studies, when a router receives a power packet...

Dynamic channel selection is among the most important wireless communication elements in dynamically changing electromagnetic environments wherein a user can experience improved communication quality by choosing a better channel. Multi-armed bandit (MAB) algorithms are a promising approach by which the difficult tradeoff between exploration to sear...

Massive IoT including the large number of resource-constrained IoT devices has gained great attention. IoT devices generate enormous traffic, which causes network congestion. To manage network congestion, multi-channel-based algorithms are proposed. However, most of the existing multi-channel algorithms require strict synchronization, an extra over...

Cognitive radio technologies have been developed to utilize the limited spectrum resources and optimize the behavior of the radio system, along with the variable radio status, by intelligent learning. The optimization can be achieved through clarifying the relationship among certain variables and target performance indices. However, today's wireles...

Brain-like communication based on spikes has potential advantages in terms of energy consumption, but it is unclear what type of encoding of information allows good robustness to errors. This paper shows how to construct Error Correcting Codes that are particularly applicable to spike-based signals. We adopt an encoding based on Inter-Spike Interva...

Reinforcement learning involves decision-making in dynamic and uncertain environments and constitutes a crucial element of artificial intelligence. In our previous work, we experimentally demonstrated that the ultrafast chaotic oscillatory dynamics of lasers can be used to efficiently solve the two-armed bandit problem, which requires decision-maki...

The wide spread of mobile communication devices has increased the opportunities to use wireless communication technologies, irrespective of one's geographical location. However communication quality deteriorates due to factors such as competition for scarce radio resources and interference among nearby devices. Cognitive radio technologies have bee...

arXiv:1803.09425 https://arxiv.org/abs/1803.09425

Recently, various mobile communication systems have been widely deployed, and mobile traffic is increasing. However, the bandwidth available for mobile communications is limited, hence the scarcity of radio resources in mobile communications is a serious problem. As an approach to solve this problem, cognitive wireless communication models have bee...

An optimization method based on energy minimization of the Ising Hamiltonian has been proposed in recent research (S. Utsunomiya et al., Optics Express 19, 2011). Large-scale implementation of such a high-speed optimization method has also been proposed. (T. Inagaki et al., Science, 234, 2016). This paper introduces the quantum neural networks, tha...

Software defined networking (SDN) is a network architecture with a programmable control plane (e.g., controllers) and simple data plane (e.g., forwarders). One of the popular SDN protocols/standards is OpenFlow, for which researchers have recently proposed some quality-of-service (QoS) supports. However, the proposals for rate allocation have some...

A power packet dispatching system is proposed to realize the function of power on demand. This system distributes electrical power in quantized form, which is called power processing. This system has extensibility and flexibility. Here, we propose to use the power packet dispatching system as the next generation power distribution system in self-es...

The previous researches on the chaotic CDMA have theo-retically derived the chaotic sequences having the minimum asynchronou cross-correlation. To minimize the asynchronous cross-correlation, auto correlation of each sequence have to be C(τ) ≈ C x r , r = τ2+√3 dumped oscillation with increase of the lag There are several methods t generate such se...

To understand information processing in the brain, it is important to clarify the neural network topology. We have already proposed the method of estimating neural network topology only from observed multiple spike sequences by quantifying distance between spike sequences. To quantify distance between spike sequences, the spike time metric was used...

In our research, we propose a novel synchronization scheme based on noise-induced synchronization. We introduce natural environmental noise as an additive input noise to uncoupled nonlinear oscillators. The natural environmental noises in neighboring areas are cross-correlated, and we have already shown that limit-cycle oscillators can be synchroni...

This paper presents an energy-efficient resource allocation scheme in ad hoc networks. First, we formulate the problem, that maximizes the tradeoff between energy efficiency and spectral efficiency, subject to constraints on power budget and quality-of-service. Next, we adopt a successive convex approximation (SCA) approach to cast the NP-hard nonc...

Interference management is one of the most critical issues in underlaying device-to-device (D2D) communication due to the coexistence of D2D pairs and cellular users that operate under the same spectrum. In this paper, we provide the interference management algorithm to maximize the performance of the D2D communication while satisfying the quality-...

In the conventional spread spectrum communication systems, the spreading codes generated by linear shift registers have been used. On the other hand, in previous researches on chip-asynchronous CDMA (code division multiple access) systems, effectiveness of the spreading codes generated by the chaotic dynamical systems have been shown by numerical s...

In order to enable the benefits of device-to-device (D2D) communications underlay cellular networks, two fundamental problems need to be addressed: 1) how to control the interference to guarantee the quality-of-service (QoS) of cellular user and 2) how to allocate transmit powers among D2D pairs to maximize the data rate. In this letter, we propose...

Cognitive radio technology improves efficiency of radio resource usage and quality of services in congested mobile networks, by reconfiguring the wireless connection settings according to the optimum decisions, which are made based on the collected context information. This paper focuses on the optimization algorithms for the decision-making to opt...

In recent years, practical research related to distributed power generation and networked distribution grids has been increasing. This research uses a relatively abstract model for the cost reduction in the Digital Grid Power Network. In the Digital Grid, the traditional wide-area synchronous grid is divided into smaller segmented grids which are c...

We propose a method for controlling synchronization patterns of limit-cycle oscillators by common noisy inputs, i.e., by utilizing noise-induced synchronization. Various synchronization patterns, including fully synchronized and clustered states, can be realized by using linear filters that generate appropriate common noisy signals from given noise...

The phases of nonlinear limit-cycle oscillators can be synchronized by adding identical noise sequence to each of them, which is called noise-induced synchronization. In our previous researches, we have shown that the nonlinear oscillators synchronize even by adding natural environmental noise or fluctuations. Because the natural fluctuations, such...

Cognitive radio technology improves radio resource usage by reconfiguring the wireless connection settings according to the optimum decisions, which are made on the basis of the collected context information. This paper focuses on optimization algorithms for decision making to optimize radio resource usage in heterogeneous cognitive wireless networ...