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Assuming the bidding on balancing market of photovoltaic (PV) system, critical issues are adequate determination of amount of bid and decision making on whether to make a bid or not. This study proposes a rule‐based scheme handling this problem regarding the trade‐off between opportunity loss and penalty event where the actually generated power becomes less than the bid. The amount of bid is adjusted by utilizing trend information of PV output error, and the execution of bidding is decided based on probability of exclusion from the market calculated using queueing theory. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Discussed here are real-valued signal analysis and wireless baseband transmission, a system for transmitting baseband signals directly from an antenna, and transmission characteristics under a multipath environment. The field of wireless transmission generally handles band signals in which information rides on a carrier wave, and therefore signal analysis is not the direct analysis of real high-frequency signals (real-valued signals) and is performed with a system expressed using complex numbers, called an equivalent baseband system. However, wireless baseband transmission is based on a transmission system which does not use carrier waves and cannot be handled with an equivalent baseband system. Consequently, it is necessary to have a system of real-valued signal analysis for handling baseband signals, which are real-valued signals, without additional processing. The BER (bit error rate) was used as the standard for evaluating transmission characteristics under a multipath environment of wireless baseband transmission using measured channel characteristics with that algorithm. With a computer, the BER characteristics were found by varying the reflection coefficient, number of delay symbols, the ratio of direct wave power and reflected wave power, and the number of reflected waves. As a result, it was clear that the dominant factor in a multipath environment is the ratio of direct wave power and reflected wave power. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(10): 9–22, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20347 [ABSTRACT FROM AUTHOR]

Orthogonal frequency division multiplex (OFDM) modulation systems can completely prevent intersymbol interference due to multipath propagation by providing a guard interval which is longer than the maximum delay hereafter we call “delay spreading.” In an environment in which the delay spreading exceeds the guard interval, on the other hand, intersymbol interference occurs. This study considers a MIMO-OFDM system in which a MIMO configuration with high diversity gain is introduced into the OFDM modulation scheme, and discusses the transmission characteristics of maximal ratio combining transmission (single-stream transmission). It is shown that the MIMO-OFDM system is less affected by intersymbol interference due to the delay, even if the delay spread exceeds the guard interval, and that good performance is achieved. It is also shown that the channel response which is required in real-time control can be estimated with sufficient accuracy. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 88(12): 29–39, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20209 [ABSTRACT FROM AUTHOR]

In this paper, a typical mobile communication environment is assumed and the eigenvalue distributions of the correlation matrix of a MIMO channel with the spatial correlation of the multipath taken into account are studied by simulation. Based on this study, a simple method is proposed for accurately deriving the probability distribu- tion of the largest eigenvalue of the correlation matrix. The proposed approximation equation is compared with simu- lation results and good agreement is obtained. In order to understand the information transmission capability of MIMO in a multipath fading environment with spatial correlation, the proposed equation is used for studying the effect of the spatial correlation on channel capacity. Finally, the digital transmission characteristics (relationship be- tween the BER and the CNR) with correlation taken into account are obtained. [ABSTRACT FROM AUTHOR]

This paper describes a method that realizes wide-band beamforming efficiently. In the proposed method, the band-division processing is applied where the signal received from the array sensor is divided into the low- and high-frequency components and the fan-filter with the wedge-shaped transition region and an adequate order is applied to each of the divided bands. The mid-point of the bend is defined as the stopband edge of the lower band filter for dividing the band so that one-half low- speed processing is applied to the lower band and the lower-band fan filter is realized by a lower order. The upper-band fan filter is designed efficiently by including the high-pass filter for the band division. A design example is presented, and it is shown that both the computational complexity and the number of sensors are considerably reduced compared to the case of the direct design. In other words, it is shown that the band division is effective. [ABSTRACT FROM AUTHOR]