Originalities of HD-PLC
1) Adopting highly frequency efficient "Wavelet-OFDM" *1) modulation method
HD-PLC uses a high frequency efficient Wavelet-OFDM modulation method. The theoretical maximum data transmission rate is up to 210Mbps. It has deep filter characteristics with flexible notch-filter features without using any external circuits (see fig.1).
The programmable notch filter enables the prevention of HD-PLC interference with other radio frequency transmissions such as amateur radio.
- *1) Wavelet OFDM method
Wavelet OFDM is a highly frequency efficient broad-band data transmission technology, which orthogonalizes sub-carriers by using the wavelet transform.Wavelet OFDM minimizes side-lobe level due to the orthogonalities in both frequency and time domains.
fig.1:Wavelet-OFDM of "Wavelet-OFDM" and conventional "FFT OFDM"
Wavelet OFDM has the deep filter property and realizes flexible notch filter without using external circuits.
2) The New Channel estimation technology
On the power line, the complex transmission line noise is estimated by the channel estimation technology.
This works to maximize data rate and stability.
The estimation technology allows for maximum amount of data to reach each sub-carrier, depending on the S/N ratio, and to maximize the data transmission rate.
Noise on the power-line comprises factors such as: long term fluctuation from home appliances and short term fluctuations from devices such as the AC adapters for mobile phones. The estimation method learns the line characteristics and empirically maximizes the transmission rate.
3) Powerful encryption method and easy set-up
HD-PLC must be functional with conventional home appliances. Our foremost goal is to achieve a secured plug-and-play scheme without requiring a PC or running any software.
The HD-PLC network authentication and the powerful encryption technology (AES 128 bit) *2) can be set up by pushing button and can be completed in 5 seconds.
- *2) AES: Next generation encryption method selected by NIST(: National Institute of Standards and Technology), a federal agency within the U.S. Department of Commerce.
4) Convenient function in order to measure transmission rate.
With this function, users can easily retrieve the communication status of the outlets. When plugging in a terminal unit (which is registered with a master unit) into an outlet and pushing the SETUP button, users can view the data transmission rate on the LED display of the terminal unit.