Abstract: A transmitter, receiver, and communication system that utilize a pseudo-random number sequence (PRNS) output unit that provides a PRNS of length N. The PRNS output unit generates the PRNS responsive to a number (s) of prescribed positive integers (qx), a prescribed real impulse constant (r), and a prescribed non-zero real constant (C), where 1<x<s. The PRNS output unit includes an input acceptance section that accepts the number (s) of real number sequence initial values (Yx), and the number (s) of integer parameters (px); and a calculation section that uses the prescribed real impulse constant (r), the prescribed non-zero real constant (C), the real number sequence initial values (Yx), the integer parameters (px), and the prescribed positive integers (qx) to calculate a recurrence formula that is used to generate a PRNS (z′[y]) of length N, and that outputs the PRNS (z′[y]), where 1<y<N.

Abstract: A reciprocating optical modulation system includes a device that modulates light of a predetermined frequency by an integer multiple n to produce a group of nth order sidebands thereof; a device that modulates the nth order sidebands to produce (n+1)th order sidebands; and a device that selects at least part of the (n+1)th order sidebands.