A remote control unit has an infrared transmitter which includes a coding device for correlating a coded series pulse train to each of a plurality of channels. The unit also includes at least one infrared receiver having a decoding device for decoding the coded series pulse trains received from the trasmitter....http://www.google.co.uk/patents/US4267606?utm_source=gb-gplus-sharePatent US4267606 - Wireless, multi-channel remote control unit for toys
