Patent ID: 7257608
Filing Date: 2007-08-14
Classification: G06F,G06N

Abstract:
1. A computer system outputting a sequence of pseudo noise codes for code division multiple access communication comprising: (a) a first storage which stores vector x of dimension at least 1; (b) a first calculator which calculates vector x′=f(x) which utilizes a first rational vector map f to which the vector x stored in said first storage is input; (c) a second storage which stores vector y of dimension at least 1; (d) a second calculator which calculates vector y′=g(x, y) which utilizes a second rational vector map g to which the vector x stored in said first storage and the vector y of dimension at least 1 stored in said second storage are input; (e) an output which outputs to a transmitter and a receiver, vector z′ which is association of the vector x′ resulting from said first calculator and the vector y′ resulting from said second calculator, as a pseudo noise code for code division multiple access communication; (f) a first update which updates said first storage by storing the vector x′ resulting from said first calculator; and (g) a second update which updates said second storage by storing the vector y′ resulting from said second calculator, where the rational vector map is a map which converts vector of dimension at least 1 having rational number components into another vector of dimension at least 1 having rational number components, and wherein said transmitter obtains said vector z′ from said output, multiplies a transmission signal sequentially by the elements of the vector z′ to perform direct-spectrum spreading, and transmits the direct-spectrum spreaded signal to said receiver, and said receiver obtains said vector z′ from said output, receives a transmitted signal from said transmitter, multiplies the received signal sequentially by inverse number of the elements of the vector z′ to perform direct-spectrum inverse spreading, and obtains the transmission signal from said transmitter.