Patent ID: 9225406
Filing Date: 2015-12-29
Classification: H04B,H04L

Abstract:
1. A signal processing method comprising: acquiring a reception signal based on a plurality of precoded signals z1 and z2; demodulating the reception signal in accordance with a transmission scheme of the plurality of precoded signals z1 and z2; performing error-correction decoding on the demodulated signal; and acquiring audio data from the error-correction decoded signal, and externally outputting the audio data, wherein the plurality of precoded signals z1 and z2 are transmitted in the same frequency bandwidth at the same time, the plurality of precoded signals z1 and z2 are generated by (i) selecting one matrix from among N matrices F[i] by regularly hopping between the N matrices F[i] which are each selected at least once within a predetermined time period and (ii) multiplying the selected matrix by two baseband signals s1 and s2 that are represented by in-phase components and quadrature components, where N is an integer 1 or greater, and i is an integer from 0 to N−1, the N matrices F[i] are two-by-two matrices that satisfy a first condition, a second condition, and a third condition, the first condition is that x is an integer from 0 to N−1, y is an integer from 0 to N−1, and with respect to all x and all y satisfying x≠y, F[x]≠F[y] holds, the second condition is that x is an integer from 0 to N−1, y is an integer from 0 to N−1, and with respect to all x and all y satisfying x≠y, no real or complex number k holding F[x]=k×F[y] exists, the third condition is that the plurality of precoded signals z1 and z2, two baseband signals s1 and s2 and the N matrices F[i] satisfy Equation (1), where, β is a positive real number, and β≠1, θ λ indicates a phase rotation amount [radian], δ indicates a phase rotation amount [radian], and j is an imaginary unit.