In piezoelectric energy harvesting systems, energy harvesting circuits are the interface between piezoelectric devices and electrical loads. The conventional view of this interface is based on the concept of impedance matching. In fact, in the power supply circuit can also apply as an electrical boundary conditions, such as voltage and charge, to piezoelectric devices for each energy conversion cycle. The major drawback of piezoelectric power harvesting have low-power relationships in systems within (in the range of μW to mW), then system also have significantly reduced any potential losses in circuits that make up the EH system, whereas other condition into careful selection of circuits and components can enhanced the energy harvesting performance and electricity consumption. In the study of energy harvesting systems, it is an energy harvesting system approach that using active and passive electronic circuit to control voltage and or charge on piezoelectric devices as proposed and review to mechanical inputs for optimized energy conversion. Several factors in the practical limitation of active and passive energy consumption, due to device limitations and the power efficiency of electronic circuits, will be introduced and have played an important role into to enhance optimum and increase efficiency of energy harvesting system.

Visible light communication (VLC) technology offers unregulated, unlicensed and huge bandwidth to meet the growing demand in future indoor communication system. One of the major challenge in VLC system is in improving transmission speed with optimize the bandwidth capacity. The method to improve spectral usage is using advanced modulation formats such as orthogonal frequency division multiplexing (OFDM). In this work, a new approach for modulation technique based on multiband OFDM has been developed which capable to improve the spectral efficiency and optimize the data rate. A proposed technique is then adapted in OCDMA-VLC environment to analyse the reliability of the proposed scheme in high capacity network. Different selection of parameter values such as bit rates, number of bands and effective received power will have different effect on the system performance. Numerical result shown that the catenated-OFDM outperforms conventional OFDM by five times spectral efficiency improvement and eight times spectral efficiency improvement at their five and eight number of bands respectively. It is also shown that the proposed catenated-OFDM design is working well even at very high bit rate of 15 Gbps. Moreover, there are enhancement in receiver sensitivity with 7.3 dB power penalty compared to previous work.

In this paper, an electronic instrument was developed that can detect electrical energy without using the conventional probes. The proposed system can detect th

VLC (or visible light communication) has grown in popularity in recent years. For next-generation communication system upgrades, dependable data transmission is essential. As the number of VLC system users increases, so does the need for consistent, rapid, and minimally delayed data delivery. However, as more consumers demanded higher speeds, transmission errors also increased. The error correction code minimizes the overall system's data error to mitigate this effect. This study examines a design architecture for a visible light communication (VLC) transmission system that incorporates forward error correction code to improve error performances, suggesting its suitability as access points in 5G technology. The simulation uses version 17 of the Opti system. The proposed architecture employs the Reed Solomon code, a well-known forward error correction (FEC) channel encoding, to safeguard the baseband signal throughout its transmission over an optical channel containing all visible background sounds. An optical filter and equalizer purify an incoming optical signal by eliminating harmonic components introduced by the VLC channel and restoring signal balance. The data transmission has utilized a forward error-correcting channel encoding of RS code with a nonreturn to zero. The simulation modelled the white, spectral, red, yellow, green, and blue light to present various background sounds accessible via the VLC channel. The simulation results indicate that the system model obtains a typical level of zero-bit errors.