Patent ID: 7164722

Claim:
A radio communications system for communicating information using an impulse signal sequence including impulses having a predetermined impulse period, comprising: a transmitter for generating said impulse signal sequence using a spread signal obtained by spreading an information bit to be transmitted, for generating an amplitude-controlled impulse signal sequence by controlling respective amplitudes of impulses of said impulse signal sequence in accordance with a predefined pattern, and for transmitting said amplitude-controlled impulse signal sequence; and a receiver for generating a correlated output signal from said amplitude-controlled impulse signal sequence transmitted by said transmitter and for controlling the amplitude of said correlated output signal in accordance with said predefined pattern, each of the impulses of said impulse signal sequence has a pulse width of approximately 1 nanosecond or less such that an occupied bandwidth is on the order of approximately 1 gigahertz or more, and the amplitude-controlled impulse signal sequence comprises a first plurality of impulses having a first amplitude and a second plurality of impulses having a second amplitude different from the first amplitude, in which at least one of the impulses included in the first plurality of impulses is separated from another impulse included in the first plurality of impulses by at least one impulse included in the second plurality of impulses.