Patent ID: 6538558
Filing Date: 2003-03-25
Classification: H04B,H04W

Abstract:
A communication system comprising:a transmitter for transmitting a transmission code containing at least a first identification code uniquely assigned to said transmitter; and a receiver for receiving the transmission code, the receiver comprising: a memory for storing a second identification code; a signal processing unit for comparing a received first identification code with the second identification code stored in said memory, and for transmitting a control signal to a part to be controlled if the first and second identification codes are identical to each other; and a mode controller for switching an operation mode of said signal processing unit from a normal mode, in which said control signal to said part is transmitted when the first and second identification codes are identical, to a control signal disable mode, in which said control signal to said part is not transmitted when the first and second identification codes are identical, wherein said transmission code includes a variable code, and said memory has a variable code storage area for storing said variable code wherein, when said first identification code and said second identification code are identical to each other, said signal processing unit compares the variable code in said transmission code with the variable code stored in said variable code storage area and delivers said control signal to said part to be controlled when a match is obtained between the variable codes within a predetermined range, wherein said processing unit updates the variable code in said variable code storage area with the received variable code at the same time as the delivery of said control signal, whereby the comparison between the variable codes and the update of the variable code of said transmission code and the update of the variable code stored in said variable code storage area is performed even in said control signal disable mode.