Wireless communication system, wireless communication method, and receiver
A wireless communication system according to an embodiment is a wireless communication system, in which a transmission device transmits the training signal to a reception device such that a plurality of signal points having different amplitudes on a constellation is included, and the reception device includes: an estimation unit that estimates the signal points included in the training signal of a case where it is assumed that, an input-output characteristic in a non-linear region of an amplifier is also linear; an equalization unit that performs initial equalization on a received signal; a correction unit that corrects a signal subjected to initial equalization by the equalization unit on the basis of the signal points estimated by the estimation unit; a likelihood calculation unit that calculates, with respect to a constellation before the amplifier amplifies a signal, a likelihood of a signal corrected by the correction unit.
1 . A wireless communication system in which a reception device demodulates a signal on the basis of a training signal transmitted by a transmission device that performs single-carrier multi-level modulation,
wherein
the transmission device
transmits the training signal to the reception device such that a plurality of signal points having different amplitudes on a constellation is included, and
the reception device includes:
an estimation circuitry configured to estimate the signal points included in the training signal in a case where on the basis of characteristic information indicating an input-output characteristic including a non-linear region of an amplifier that is provided in the transmission device to amplify a signal to be transmitted, the input-output characteristic in the non-linear region of the amplifier is also linear;
an equalization circuitry configured to perform initial equalization on a received signal;
a correction circuitry configured to correct the received signal subjected to the initial equalization by the equalization circuitry on the basis of the signal points estimated by the estimation circuitry;
a likelihood calculation circuitry configured to calculate, with respect to a constellation before the amplifier amplifies the signal to be transmitted, a likelihood of the received signal corrected by the correction circuitry; and
a demodulation circuitry configured to demodulate the signal on the basis of the likelihood calculated by the likelihood calculation circuitry.
2 . The wireless communication system according to claim 1 , wherein
the reception device
receives the characteristic information from the transmission device.
3 . The wireless communication system according to claim 1 , wherein
the training signal includes
the plurality of signal points having different amplitudes on the constellation before the amplifier amplifies the signal to be transmitted.
4 . The wireless communication system according to claim 1 , wherein
the training signal
includes one signal point selected for each of regions on a predetermined constellation including the plurality of signal points.
5 . A wireless communication method in which a reception device demodulates a signal on the basis of a training signal transmitted by a transmission device that performs single-carrier multi-level modulation,
the wireless communication method comprising:
transmitting, by the transmission device, the training signal to the reception device such that a plurality of signal points having different amplitudes on a constellation is included;
estimating, by the reception device, the signal points included in the training signal in a case where on the basis of characteristic information indicating an input-output characteristic including a non-linear region of an amplifier that is provided in the transmission device amplifying a signal to be transmitted, the input-output characteristic in the non-linear region of the amplifier is also linear;
performing, by the reception device, initial equalization on a received signal;
correcting, by the reception device, the received signal subjected to the initial equalization on the basis of the signal points estimated;
calculating, by the reception device, with respect to a constellation before the amplifier amplifies the signal to be transmitted, a likelihood of the received signal corrected; and
demodulating, by the reception device, the signal on the basis of the likelihood calculated.
6 . A reception device that demodulates a signal on the basis of a training signal transmitted by a transmission device that performs single-carrier multi-level modulation,
the reception device comprising:
an estimation circuitry configured to estimate a plurality of signal points included in the training signal transmitted by the transmission device such that the plurality of signal points having different amplitudes on a constellation is included in a case where, on the basis of characteristic information indicating an input-output characteristic including a non-linear region of an amplifier that is provided in the transmission device to amplify a signal to be transmitted, the input-output characteristic in the non-linear region of the amplifier is also linear;
an equalization circuitry configured to perform initial equalization on a received signal;
a correction circuitry configured to correct the received signal subjected to the initial equalization by the equalization circuitry on the basis of the signal points estimated by the estimation circuitry;
a likelihood calculation circuitry configured to calculate, with respect to a constellation before the amplifier amplifies the signal to be transmitted, a likelihood of the received signal corrected by the correction circuitry; and
a demodulation circuitry configured to demodulate the signal on the basis of the likelihood calculated by the likelihood calculation circuitry.
7 . The reception device according to claim 6 , wherein
the estimation circuitry
estimates the signal points on the basis of the characteristic information transmitted by the transmission device.
8 . The reception device according to claim 6 , wherein
the training signal includes
the plurality of signal points having different amplitudes on the constellation before the amplifier amplifies the signal to be transmitted.