Best Paper Award 2014

Best Paper Award

An Asymptotic Property of Energy Representation with Power Packet

Shinya Nawata, Ryo Takahashi, Takashi Hikihara

[Trans. Fundamentals.（JPN Edition), Vol. J97-A No.9, Sep. 2014]

Shinya Nawata

Ryo Takahashi

Takashi Hikihara

  Power packet is a unit of power transmission by pulses with information tags. The authors’ group has developed a power packet distribution system in the physical layer. The system is realized by power packets tagged directly onto their voltage waveforms. We have developed a router for power packets which transfers power packets according to the information attached to the packets. The developed router can transfer the packets using time-division multiplexing.
  In this paper, the theoretical characteristics of energy transmission with power packets are clarified, aiming at the integration of energy transmission and information transmission based on the empirically developed apparatuses. The power packet transmission is performed by using pairs of information tags and power pulses as the minimum units. This type of transmission also appears in Shannon’s information theory as the discrete transmission of messages represented by symbol sequences. Considering the pair of information tags and power pulses as a symbol, power packet transmission is given as a problem of simultaneous representation of message and energy using symbol sequences.
  The energy representation using the symbol sequences is an operation, which is unique to power packet transmission, for compensating the total amount of required energy during a finite term. This representation is formulated using a set of symbol sequences compensating the required energy, and the theoretical proof that there appears an asymptotic property in the representation of energy by symbol sequences was given in the paper. In addition, numerical simulation was performed to confirm the theorem in a finite-energy setting. The result shows a large variance in the set of symbol sequences if the accuracy of the energy request is high. The study on energy representation is expected to explain how to generate the required energy with power packets, which will lead to systematic design of the power packet distribution system.