| 摘要 |
The application relates to a generating method and device, receiving method and device for a dual-frequency constant envelope multiplexed signal with four spreading signals. According to the method, the four baseband spreading signals s1(t), s2(t), s3(t), s4(t) can be modulated to a frequency f1 and a frequency f2 respectively, so as to generate the constant envelope multiplexed signal on a radio carrier frequency fp=(f1+f2)/2, where the signals s1(t) and s2(t) are modulated on the frequency f1 with carrier phases orthogonal to each other, the signals s3(t) and s4(t) are modulated on the frequency f2 with carrier phases orthogonal to each other, f1>f2. The method comprises: determining a power ratio allocated to the four baseband spreading signals s1(t), s2(t), s3(t), s4(t) in the constant envelope multiplexed signal; storing an additional phase lookup table, wherein the table includes additional phases of an in-phase baseband component I(t) and a quadrature-phase baseband component Q(t) of the constant envelope multiplexed signal; obtaining an additional phase θ of a segment of the current time by looking up the additional phase lookup table; and generating an in-phase baseband component I(t) and a quadrature-phase baseband component Q(t) of the constant envelope multiplexed signal, and generating the constant envelope multiplexed signal SRF(t) based on the obtained additional phase θ. |
| 主权项 |
1. A method for generating a dual-frequency constant envelope multiplexed signal with four spreading signals, in which the four baseband spreading signals s1(t), s2(t), s3(t), s4(t) are modulated to a frequency f1 and a frequency f2 respectively, so as to generate the constant envelope multiplexed signal on a radio carrier frequency fp=(f1+f2)/2, where the signals s1(t) and s2(t) are modulated on the frequency f1 with carrier phases orthogonal to each other, and the signals s3(t) and s4(t) are modulated on the frequency f2 with carrier phases orthogonal to each other, f1>f2, wherein the method further comprises:
determining a power ratio allocated to the four baseband spreading signals s1(t), s2(t), s3(t), s4(t) in the constant envelope multiplexed signal; storing an additional phase lookup table, wherein the table includes additional phases of an in-phase baseband component I(t) and a quadrature-phase baseband component Q(t) of the constant envelope multiplexed signal, and the table is configured by dividing a subcarrier period Ts of the baseband spreading signal into multiple segments and by determining, at each segment of the multiple segments, an additional phase θ for a state among 16 states of value combination of the four baseband spreading signals s1(t), s2(t), s3(t), s4(t) in the constant envelope multiplexed signal, based on the determined power ratio of the four baseband spreading signals s1(t), s2(t), s3(t), s4(t); obtaining, according to a segment of the subcarrier period of the baseband spreading signal and to a state of the value combination of the four baseband spreading signals s1(t), s2(t), s3(t) and s4(t) corresponding to the current time, an additional phase θ of a segment of the current time by looking up the additional phase lookup table; generating an in-phase baseband component I(t) and a quadrature-phase baseband component Q(t) of the constant envelope multiplexed signal, and generating the constant envelope multiplexed signal SRF(t) based on the obtained additional phase θ, where
SRF(t)=I(t)cos(2πfpt)−Q(t)sin(2πfpt),I(t)=A cos(θ),Q(t)=A sin(θ),fp=(f1+f2)/2,Ts=1/fs,fs=(f1−f2)/2, where A is the amplitude of the constant envelope multiplexed signal SRF(t). |
