Cesar Briso-Rodríguez

Universidad Politécnica de Madrid | UPM · iac

For unmanned aerial vehicle (UAV)-assisted integrated sensing and communication (ISAC) systems, a semantic-based channel state information (CSI) feedback scheme is proposed in this paper. Unlike traditional full CSI feedback, the proposed scheme minimizes feedback burden by utilizing predefined semantic databases at both the transmitter and receive...

With the deep integration between the unmanned aerial vehicle (UAV) and wireless communication, UAV-based air-to-ground (AG) propagation channels need more detailed descriptions and accurate models. In this paper, we aim to perform cluster-based characterization and modeling for AG channels. To our best knowledge, this is the first study that conce...

Unmanned aerial vehicles (UAVs) have attracted increasing interest in integrating them in next-generation wireless communication. It has reached a consensus that unmanned aerial system (UAS) plays an intensely crucial role in the emerging aerial networks. Concerning connected UAV, a multitude of communication scenarios are involved, such as interco...

In order to implement unmanned aerial vehicle (UAV)-based wireless communications, a better understanding of wireless channels and the corresponding channel characterizations are critical. In this paper, air-to-ground (AG) channel measurements are carried out at some candidate frequencies, i.e., 1 GHz, 4 GHz, 12 GHz, and 24 GHz. With measurement da...

High-speed trains are one of the most relevant scenarios for the fifth-generation (5G) mobile communications and the “smart rail mobility” vision, where a high-data-rate wireless connectivity with up to several GHz bandwidths will be required. This is a strong motivation for the exploration of millimeter wave (mmWave) band. In this article, we...

Powered by the Internet of Things (IoT), the cellular, vehicular, and other emerging networks such as space-air-ground integrated networks are expected to comprehensively evolve into the new era of the Internet of Everything (IoE) in which the propagation links between IoT devices or sensors become diversified. Thus, a general propagation channel m...

Wireless communication has been a fundamental part of railway operation, control, and service systems for decades. In the era of 5G and beyond, the railway communication system is evolving from critical signaling to support various functions to improve the convenience, efficiency, and safety of railway services. Millimeter-wave (mmWave) bands and r...

The purpose of this special issue is to provide the academic and industrial communities an excellent venue to present the vision, research, and dedicated efforts on the key emerging technologies for smart rail mobility. Rail transport networks are now reaching an important development stage worldwide. High-speed rail transports have achieved signif...

Passenger trains and especially metro trains have been identified as one of the key scenarios for 5G deployments. The wireless channel inside a train car is reported in the frequency range between 26.5 GHz and 40 GHz. These bands have received a lot of interest for high-density scenarios with a high-traffic demand, two of the most relevant aspects...

The next generation of mobile communications, 5G, will provide a wideband network based on microwave and millimeter-wave (mmW) communication radio links with the goal of fulfilling the strict and severe requirements of the future test cases. In particular, this paper research is focused on mmW bands in metropolitan railway tunnels. For that purpose...

Railway, subway, airplane, and other transportation systems have drawn an increasing interest on the use of wireless communications for critical and noncritical services to improve performance, reliability, and passengers experience. Smart transportation systems require the use of critical communications for operation and control, and wideband serv...

High-speed railways (HSRs) improve the quality of rail services, yield greater customer satisfaction, and help to create socioeconomically balanced societies [1]. This highly efficient transport mode creates significant challenges in terms of investment, technology, industry, and environment. To handle increasing traffic, ensure passenger safety, a...

In this work, an evaluation of the fourth generation (4G) waveform performance in underground tunnel scenarios has been carried out with the help of hardware testbeds. The equipment for the measurements has been deployed inside the carriage of an underground train, and the antenna elements were located both outside and inside the carriage. The expe...

Railway and telecommunication companies have showed a great interest in deploying broadband mobile wireless networks in high-speed trains with the aim of supporting both provisioning of passenger services and automatic train control and signaling. This motivates the study of broadband wireless communications between a base-station transmitter and a...

High-speed rail line consists of a variety of complex terrain structures. To ensure the stability of radio signal transmission, a detailed channel modeling for this special environment is essential and valuable. In this work, an evaluation of the performance of radio propagation in a high speed railway cutting scenario is conducted. The correspondi...

The fast development of high speed railway (HSR) promotes the evolution process of wireless communication system. An accurate time delay line (TDL) channel model in HSR environments is thus necessary. In this paper, the correlation property of multi-path components based on empirical measurements at 950 MHz with 33 MHz bandwidth are characterized i...

By summarizing extensive literature, this paper presents a panorama of the path loss exponent and shadow fading distribution in the main rail traffic scenarios. This panorama is very useful to gain a comprehensive understanding of the propagation. Moreover, with the aid of the table provided in this paper, designers can easily realize a fast networ...

High-speed railway (HSR) brings convenience to peoples’ lives and is generally considered as one of the most sustainable developments for ground transportation. One of the important parts of HSR construction is the signaling system, which is also called the “operation control system,” where wireless communications play a key role in the transmissio...

Orthogonal Frequency Division Multiplexing (OFDM) communications under highly time-selective channels are severely affected by Inter-Carrier Interference (ICI). Estimation and cancellation of ICI in OFDM systems has been thoroughly studied, but few empirical measurements of the performance of such techniques have been done. We present a wireless co...

The wave propagation in tunnels does not only depend on the carrier frequency and properties of the tunnel, but also differs along with the distance between transmitter (Tx) and receiver (Rx). This letter presents a complete structure and model for propagation in tunnels. Compared to existing models, the complete model unifies different academic vi...

The propagation situations inside tunnels vary with the distance between transmitter and receiver, as well as the relative size of the users. This paper presents a novel hybrid propagation model covering three propagation mechanisms with two types of users. In the first case, the users are relatively small in size compared with the tunnel. The enti...

Accurate characterization of the radio channel in tunnels is of great importance for new signaling and train control communications systems. To model this environment, measurements have been taken at 2.4 GHz in a real environment in Madrid subway. The measurements were carried out with four base station transmitters installed in a 2-km tunnel and u...

There is no unanimous consensus yet on the propagation mechanism before the break point inside tunnels. Some deem that the propagation mechanism follows the free space model, others argue that it should be described by the multimode waveguide model. Firstly, this paper analyzes the propagation loss in two mechanisms. Then, by conjunctively using th...

A high performance wireless network is essential for for the railway communication and control systems. Research on the fading characteristics in railway environment is of great importance for the design of the railway wireless network. In this paper, measurements are taken in railway terrain cuttings area using track side base stations of the GSM-...

The delay caused by the reflected ray in broadband communication has a great influence on the communications in subway tunnel. This paper presents measurements taken in subway tunnels at 2.4 GHz, with 5 MHz bandwidth. According to propagation characteristics of tunnel, the measurements were carried out with a frequency domain channel sounding techn...

Communications Based Train Control Systems require high quality radio data communications for train signaling and control. Actually most of these systems use 2.4GHz band with proprietary radio transceivers and leaky feeder as distribution system. All them demand a high QoS radio network to improve the efficiency of railway networks. We present narr...

This paper focuses on one vital aspect in propagation characteristics inside subway tunnels: near shadowing phenomenon in a practical environment. In order to characterize this effect, an accurate measurement has been made at 2.4 GHz in a real environment in Madrid subway. By analyzing the numerical results in this measurement, the characteristic o...

In this paper, outage probability caused by multiple interferers in Nakagami-m fading channels is studied. A novel method is proposed to derive the exact and closed form expressions of outage probability in the presence of multiple Nakagami independent cochannel interference. Unlike some previous conclusions, the method proposed in this paper is no...

This paper focuses on three vital aspects in propagation characteristics inside tunnels: break point; near zone and far zone in a practical environment. Firstly, all the distinguishing features of radio channel in the areas before and after break point at different angles such as modal theory, ray-tracing theory, statistics and propagation model ha...

Transmission interference is a key performance indicator of railway digital mobile communication system(RDMCS), whose performance will become worse in high-speed railway. The factors that influence the transmission interference of RDMCS are analyzed. Based on the relationship between speed and transmission interference, the scheme based on distribu...

Modern heterodyne ultra low noise receivers used for radio astronomy have evolved to provide very wide instantaneous bandwidth. Some of the configurations used in present cryogenic front-ends, such as sideband separating mixers and balanced amplifiers, require 90?? hybrids as a part of the intermediate frequency (IF) circuitry. A very common choice...

This paper covers some of the work carried out in the planning of the global system for mobile communication for railway (GSM-R) of the tunnels on the new high-speed trains in Spain. Solutions based on distributed antenna systems have been tested by installing several 900-MHz transmitters inside and outside of a 4000-m tunnel and measuring the prop...

Broadband portable communications equipment demands frequency synthesizers with low phase noise, Hz resolution, fast tuning, low size and low power consumption. This paper describes the development of a high performance synthesizer for a portable transceiver able to cover wide-band width fast tuning (17μs), Hz resolution, low phase noise (-100 dBc...

A novel systematic and consistent method for two-branch channelized active bandpass filter design is presented. The design technique is obtained starting from a rigorous and detailed theoretical analysis of this type of filter, undeveloped to date. In the proposed method, the values of key design parameters are established directly from the initial...

The Ray and the Waveguide Theories are used in order to establish a good basis for studying the propagation of radio waves inside a tunnel. This can be regarded as an oversized hollow rectangular waveguide with a breakpoint that splits the study in two different zones, the near field region and the far field region. The losses in propagation are du...

In this paper channelized active filter structures are presented as a good solution to achieve highly selective responses. These structures allow to obtain filters with unconditional stability, high gain and small dimensions. Furthermore, a new and systematic method for two-branch channelized filter design is also proposed. Theoretic results are va...

This paper presents a complete land mobile channel simulation system composed by a hardware channel emulator, control program for hardware control and channel modeling and graphical representation software. The complete system is a powerful tool for the study and research of mobile communications

This article presents results on LMDS channel modeling of a wide-band measurement campaign conducted in the urban environment (Madrid-Spain). The objective of this work is to classify propagation channel impairments according to simple environmental parameters rather than to specific path profiles or vague descriptions

A blend of high-quality hardware and control software is needed in modern instrumentation to accurately emulate the characteristics of mobile communications channels.

Research on radio-wave propagation in tunnels has important aplications for systems communicactions in railways networks. In this paper we will propose a modal method to model the radio propagation channels in rectangular tunnels. This model agrees with models based on ray-tracing when the tunnel is ideal, and depends on the frequency, the antenna...

This paper shows a method for SMATV networks characterization witch it is possible to make a prediction about their behavior in all bandwidth. This method is based on the network simulation starting from the measurement and getting of S parameters of the specific devices of the mechanisms that integrate it. Simulations had been contrasts with measu...