| 摘要 |
The transmission of telecommunication signals according to the method is by use of a power amplifier (40) designed to amplify simultaneously several signals modulating different carriers with frequencies (f1,f2,f3) and comprises the input of modulated carriers to power-estimating devices (22,24,26) and the clamping of the composition of carriers signal upstream of the amplifier (40), which is associated with a digital pre-distortion organ (36) for linearizing the amplifier. The threshold of clamping depends on the sum of powers (P1+P2+P3) of signals to be transmitted, and at least one parameter (I,U) of functioning of the amplifier depends on the sum of powers so to maintain an optimal output of the amplifier and/or to minimize the difference between the saturation power and the average power of utilization. <??>The parameters of functioning of the amplifier (40) are supply voltage (U) and the polarization current (I). The clamping threshold is determined by a variable-gain element (38) associated with a clamping organ (32) providing a constant radius of clamping. The modification of gain caused by the modification of the clamping radius is compensated by a modification of gain in opposite sense so that the product of two gains is substantially equal to unity. The parameters of functioning of the amplifier (40) are varied at a sufficiently low rate so to allow the updating of the parameters of linearization of the amplifier. The point of functioning of the amplifier is fixed so that the maximum admissable power is slightly higher than the power necessary for the transmission of supplementary power on a rapid request. The margin of supplementary power is about 10%. The signals are transmitted in the Code Division Multiple Access (CDMA) mode for each carrier, and the power is evaluated on the length of at least one symbol during each time interval The symbol utilized for the estimation is longer than the time interval. The estimation is effected at the rate of coding bits. The carriers are situated in adjacent bands. The application of the method is to a base station of a telecommunication system, or to a terminal of the telecommunication system. |
