Device and method for sending signal through multi-carrier mode

Abstract

A transmitter is used which transmits transport symbols by use of the multicarrier system. The transmitter has a means for adjusting the phase rotation amount of each of N data symbols; a means for subjecting the data symbol as phase adjusted to an inverse Fourier transform process to generate a transport symbol; and a phase calculating means for deciding the phase rotation amount by use of a complex neural network. The phase calculating means has N neurons that derive, from N complex input signals to which temporarily decided phase rotations have been applied, a single complex output signal as subjected to the inverse Fourier transform process and that provides the complex output signal as a next complex input signal; and a condition updating means that updates the phase rotation amount in accordance with the value of a target function calculated from the complex output signal. In this way, appropriate weights can be applied to the signal components for each of subcarriers transmitted by use of the multicarrier system, thereby sufficiently suppressing the ratio of peak power to average power (PAPR) of the transport signal.

Description

technical field [0001] The present invention relates to the technical field of multi-carrier communication methods such as Orthogonal Frequency Division Multiplexing (OFDM: Orthogonal Frequency Division Multiplexing), and more particularly to a device and method for transmitting and receiving signals with suppressed peak power. Background technique [0002] OFDM and OFDMA (Orthogonal Frequency Division Multiple Access: Orthogonal Frequency Division Multiple Access) have been used in terrestrial digital TV broadcasting and microwave access global interoperability (WiMAX: Worldwide Interoperability for MicrowaveAccess), and are also planned to be used in 3.9 / communication method of the 4th generation mobile phone system. A signal transmitted by the OFDM (A) method is generated by combining a plurality of subcarriers, so when the phases of the plurality of subcarriers match, extremely high peak power is generated. When the peak power is high, correspondingly more transmissio...

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Problems solved by technology

Therefore, there always remains the possibility that the peak power does not reach a true minimum, and especially with a small number of subcarriers, the peak power may not be adequately suppressed

[0036] The second problem is that since the phase inversion is accompanied by a large change from positive to negative, or from negative to positive, the objective function is generated before and after the state update of the repetitive optimization algorithm It is difficult to guarantee the continuity, stability and reliability of the calculation due to the sharp change of the value

[0037] The third problem is the computational complexity

However, since the neural network used in the above method is a real number type, this method introduces two real number variables, the real part and the imaginary part, for a polar coordinate type complex number of one variable, and a complex repetitive algorithm must be executed.

[0038] In addition, this method uses a complex objective function (polynomial with state update), so as the number of symbols (number of sub-channels) increases, the calculation formula becomes extremely complex, and the calculation speed is slow, so it cannot be said to be an effective method

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