Pre-coding method and pre-coding device

摘要

Disclosed is a precoding method comprising the steps of: generating a first coded block and a second coded block with use of a predetermined error correction block coding scheme; generating a first precoded signal z1 and a second precoded signal z2 by performing a precoding process, which corresponds to a matrix selected from among the N matrices F[i], on a first baseband signal s1 generated from the first coded block and a second baseband signal s2 generated from the second coded block, respectively; the first precoded signal z1 and the second precoded signal z2 satisfying (z1, z2)T=F[i](s1, s2)T; and changing both of or one of a power of the first precoded signal z1 and a power of the second precoded signal z2, such that an average power of the first precoded signal z1 is less than an average power of the second precoded signal z2.

主权项

1. A transmission method comprising:
selecting one precoding scheme from among N precoding schemes by hopping between the N precoding schemes, for each of a plurality of slots, the N precoding schemes being represented by N precoding matrices F[i] respectively, where i is an integer no less than 0 and no more than N−1, and N is an integer 3 or greater; applying a power change to a first modulated signal s1 and a second modulated signal s2; performing a precoding process according to the selected precoding scheme on the first modulated signal s1 and the second modulated signal s2 to which the power change has been applied, thereby generating a first transmission signal z1 and a second transmission signal z2; and transmitting the first transmission signal z1 and the second transmission signal z2 respectively from a first antenna and a second antenna at the same time at the same frequency, wherein the precoding matrices F[i] satisfyF⁡[i]=1α2+1⁢(ⅇjθ11⁡(i)α×ⅇj⁡(θ11⁡(i)+λ)α×ⅇjθ21⁡(i)ⅇj⁡(θ21⁡(i)+λ+π)) where λ=0 radians, and α=1,
θ11(i) and θ21(i) satisfy
ej(θ11(x)-θ21(x))≠ej(θ11(y)-θ21(y)) for ∀x,∀y(x≠y;x,y=0,1,2, . . . ,N−2,N−1), and the power change involves multiplication of the first modulated signal s1 by a weighting factor ua and multiplication of the second modulated signal s2 by a weighting factor ub that is different from the weighting factor ua.