Transmitter, transmission method in which a radio communication system comprising a receiver and those receiving a radio signal from a transmitter

The transmitter assigns 560Myuesu, a frame length of 600 .mu.s to the code "0" in the binary number, 600 .mu.s to the code "1" in the binary number, a built-in table (TBL1) for allocating frame length 560Myuesu ing. The transmitter refers to the table (TBL1), the code string of transmission information represented by binary "0" to "3" [0,0], [0,1], [1,0] , each code of [1,1] "0", assigned "1" in each of the two frame lengths 560μs, 600μs and 600 .mu.s, the 560Myuesu, transmits four radio signals having their assigned four-frame length sequence to.