Method for transmitting data by means of a carrier current
View Patent ↗The invention relates to a method for transmitting data over a carrier current using a frequency band. According to said method: the frequency band is divided into N sub-bands, N being a whole number higher than, or equal to, two; an OFDM (Orthogonal Frequency Division Multiplexing) technique is carried out on each of said sub-bands; and calculations are carried out based on each sub-band. The inventive method is characterised in that the calculations based on each sub-band are independent from the calculations based on the other sub-bands, and said sub-bands are dynamically activated and allocated. The invention also relates to modulation and demodulation devices for carrying out said method.
1. A method for transmitting data on a carrier current using a frequency band, the method comprising:
subdividing said frequency band into N sub-bands, where N is an integer greater than or equal to two;
implementing an Orthogonal Frequency Division Multiplexing (OFDM) technique on each of said sub-bands, said sub-bands being activated and allocated in dynamic manner; and
performing calculation operations on each of the sub-bands;
wherein the calculations performed on each of the sub-bands are independent of the calculations performed on the other sub-bands;
wherein said subdividing of said frequency band comprises using a bank of filters suitable for subdividing said frequency band into N sub-bands;
wherein said performing of calculation operations comprises synchronization that is carried out independently starting from each these sub-bands; and
wherein said synchronization includes performing a Fourier transform of a first time sample to produce a first frequency sample, calculating a first angle of rotation for a first pilot carrier, calculating a second angle of rotation for a second pilot carrier, deducing a third angle of rotation for a middle carrier of the first frequency sample, and providing the third angle of rotation for a second time sample prior to performing a Fourier transform of the second sample, the second time sample being subsequent to the first time sample.
2. A method for transmitting data on a carrier current according to claim 1 , characterized in that the filters of said bank have filtered sub-bands that overlap.
3. A method for transmitting data on a carrier current according to claim 2 , characterized in that the frequencies present in said overlaps are not used.
4. A method for transmitting data on a carrier current according to claim 1 , characterized in that the number N of sub-bands is equal to 7.
5. A method for transmitting data on a carrier current according to claim 1 , characterized in that the OFDM symbols have a size equal to 256 carriers.
6. A method for transmitting data on a carrier current according to claim 1 characterized in that the sub-bands are activated and allocated in dynamic manner by a non-transitory computer readable medium encoded with computer executable instructions.
7. A method for transmitting data on a carrier current according to claim 1 , characterized in that the sub-bands are activated and allocated in dynamic manner by hardware means.
8. Modulation and demodulation equipment for implementing the method according to claim 1 , comprising filtering means, fast Fourier transform (FFT) calculation means, analog-to-digital converter (ADC) means, amplifier means, means for activating and allocating the sub-bands, and means for synchronization.