Patent ID: 8539520

Claim:
An apparatus for generating reference signatures, the apparatus comprising: a first multiplexor to multiplex first signals received from a plurality of media sources at respective first intervals of time to generate a first multiplexed signal; a first reference signature generator to generate a first reference multiplex of reference signatures from the first multiplexed signal; a first demultiplexor to demultiplex the first reference multiplex to generate first reference signatures representative of media provided by the plurality of media sources during the respective first intervals of time; a second multiplexor to multiplex second signals received from the plurality of media sources at respective second intervals of time to generate a second multiplexed signal; a second reference signature generator to generate a second reference multiplex of reference signatures from the second multiplexed signal; and a second demultiplexor to demultiplex the second reference multiplex to generate second reference signatures representative of the media provided by the plurality of media sources during the respective second intervals of time, the respective second intervals of time being offset relative to the respective first intervals of time.