US 7,460,787 B2Granted

Communication system with external synchronisation

AssigneeKoninklijke Philips Electronics N.V.

InventorsPaulus Henricus Antonius Damink, Sel Brian Colak, Maurice Herman Johan Draaijer, Maurice Leonardus Anna Stassen

Life of this patent

Estimating the term…

patentgrep

Loading patent…

Abstract

In an optical communication method, an accurate common clock signal (GPS) is provided to a sender (10) and a receiver (20). In the sender, the common clock signal is received, a first clock signal (CLK1) is generated on the basis of said common clock signal, a carrier wave with a predetermined carrier frequency (f) is generated using said clock signal as timing reference, the carrier wave is modulated with a data signal, and the modulated carrier wave is transmitted using a light beam (13). In the receiver, the common clock signal is received, a reference signal having the same frequency (f) as the carrier frequency is generated on the basis of said common clock signal, said optical beam (13) is received, a detection signal is derived from the optical beam, the receiver is tuned to the predetermined carrier frequency (f), and the data signal is derived from the detection signal.

Claims13

Dependent claims

Communication method, comprising the steps of:

providing an accurate common clock signal to a sender (10) and a receiver (20);
in the sender, receiving the common clock signal, generating a carrier wave with a predetermined carrier frequency (f) using said common clock signal as timing reference, modulating the carrier wave with a data signal, and transmitting the modulated carrier wave using an optical light beam (13);
in the receiver, receiving the common clock signal, receiving said optical beam (13), deriving a detection signal from the said optical beam, generating a reference signal having the same frequency (f) as the said carrier frequency using said common clock signal as timing reference, tuning to the predetermined carrier frequency (f), and deriving the data signal from the said detection signal;
wherein the step of tuning to the predetermined carrier frequency (f) comprises the steps of:
multiplying said detection signal with said reference signal, filtering the multiplied signal with a lowpass filter, and demodulating the filtered signal.

2 more elements

Dependencies are inferred from the claim text.