The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
When using a high power amplifier(HPA) for high-speed communication, the nonlinear characteristics of the HPA cause power efficiency, bit error rate(BER) performance, and spectral efficiency to deteriorate. Since it is inevitable to use HPA to obtain sufficient transmission power for high-speed communication, it is necessary to compensate for nonlinearity of HPA by using a predistorter. In this paper,...
Modern control theories such as systems engineering approaches try to solve nonlinear system problems by revelation of causal relationship or co-relationship among the components; most of those approaches focus on control of sophisticatedly modeled white-boxed systems. We suggest an application of actor-critic reinforcement learning approach to control a nonlinear, complex and black-boxed system....
Accurate prediction of the future locations of the host vehicle as well as that of the surrounding objects is one of the key challenges in improving road traffic safety. The traditional approach for this task has been using physics-based motion models such as kinematic and dynamic models, the result of which is not reliable for long-term prediction. In this paper, we present simulation results demonstrating...
In this paper, we describe a method of frequency-hopping signal detection, which is one of the methods of spread spectrum, by time-frequency analysis. Since the frequency hopping signal is a non-stationary signal, the signal changes very quickly. Therefore, time-frequency resolution is very important for detecting such non-stationary signals. The method considered in this paper is a spectrogram and...
The millimeter wave bands will be used for 5G or IoT to overcome frequency insufficiency. This paper shows relations of received power, multipath delay spread and distance in urban low-rise environments at both 28 and 38 GHz. The wideband characteristics had been measured with a channel sounder, a directional antenna for transmitter, and an omni-directional antenna for receiver in Daejeon area.
In this paper, we consider a method to detect digital modulated symbols from compressively sampled measurements in digital communication system. We describe a method to build a dictionary matrix considering signal modulations, and propose a template matching based algorithm which is effective to recover the information symbols using the dictionary. We implement the algorithm as a GPGPU program, and...
Texture reconstruction is the last step of 3D reconstruction pipelines that makes 3D geometry models very impressive and beautiful. Once the 3D model is created through structure-from-motion, multi-view stereo and mesh reconstruction, real image based texture is mapped to the models. But it is not easy to generate high quality texture. There are many difficulties cause problems: the large number of...
In cognitive Radio Networks (CRNs), to utilize the available opportunities on the primary spectrum effectively; secondary transmitters should have a prior knowledge about the number of primary channels that are predicted to be available and hence the periods of time the secondary users can maintain the channel(s) to efficiently schedule their data while satisfying the constrains of the delivered application...
Safety and non-safety application services require a guarantee of network performance, mostly in terms of throughput and packet collision. The current radio propagation path loss models use mean additional attenuation sophisticated fading model and do not consider the obstacle caused due to obstacles of vehicles in LOS of transmitting and receiving vehicles. This affects the attenuation signal at...
As the communication systems have been increasingly complex, the problem of channel estimation for such complex communication systems has also emerged as an equally challenging task. To solve this problem, various schemes based on Least Mean Square (LMS) and its improved variants have been proposed. This paper presents an adaptive algorithm for channel estimation in non-Gaussian environment. The proposed...
In directional energy transmissions, a radio frequency (RF) energy source needs to monitor each sector to achieve higher RF energy transmission efficiency. However, since the distribution of harvesting nodes can be dynamically changed in mobile environments, it is difficult to obtain the exact numbers of harvesting nodes in all sectors within limited time. In such a situation, the operations of RF...
Recently, the development of wireless body area network (WBAN) is accelerated due to rapid development of wireless technology. In the WBAN environment, many WBANs coexist where communication ranges overlap with each other, resulting in the possibility of interference. Since many variety of applications exist in the WBAN environment, each prospective user may have different quality of service (QoS)...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.