Patent ID: 9356696
Filing Date: 2016-05-31
CPC Classification: H04B,H05B

Claim Text:
1. A light driver for driving at least one light source arranged to emit coded light based on a control signal, the light driver comprising: a receiver arranged to receive a sequence u=[u1, . . . , uk, . . . , uK] of source symbols uk representing an information sequence of an information source; a processing unit arranged to determine, from the sequence of source symbols, a sequence z=[z1, . . . , zk, . . . , zK] of channel symbols zk forming the control signal; a transmitter arranged to provide the at least one light source with the control signal thereby driving the at least one light source; wherein the processing unit is arranged to determine the sequence of channel symbols z by mapping each source symbol uk at time k to a composite channel symbol zk=(zk,1, zk,2) comprising at least one first channel symbol zk,1, one of which is identical to uk, and at least one second channel symbol zk,2 having a value chosen from a set M, wherein the value of zk,2 is determined according to a weighting function having the source symbol uk and at least one future and/or past source symbol ui, i≠k as input arguments, the weighting function comprising at least two non-zero weighting factors, the mapping resulting in that the power spectral density at frequency zero of the sequence z of channel symbols is equal to zero, and wherein the control signal thereby enables no visible flicker to be present in coded light emitted by the at least one light source.