Wireless communication method, transmitter, receiver, and wireless communication system
A radio communication method according to an embodiment is a radio communication method for transmitting a signal from a transmitter to a receiver using a single carrier, in which the transmitter generates two or more training signals using a symmetric subcarrier at the time of training to perform an OFDM modulation, and shapes a spectrum of each of the OFDM-modulated training signals to be close to a single carrier spectrum, and in which the receiver adjusts the timing of two or more training signals, using a single carrier time domain correlation sequence at the time of training, estimates a channel response and an IQ imbalance from the two or more training signals whose timing is adjusted, compensates for the estimated IQ imbalance, and demodulates the compensated signal.
1 . A radio communication method for transmitting a signal from a transmitter to a receiver using a single carrier,
the transmitter
generating two or more training signals using a symmetric subcarrier at a time of training to perform an Orthogonal Frequency Division Multiplexing (OFDM) modulation, and
shaping a spectrum of each of the OFDM-modulated training signals to be close to a single carrier spectrum, and
the receiver
adjusting timing of the two or more training signals, using a single carrier time domain correlation sequence at the time of training,
estimating a channel response and an in-phase (I) and quadrature (Q) (IQ) imbalance from the two or more training signals whose timing is adjusted,
compensating for the estimated IQ imbalance, and
demodulating the compensated signal.
2 . The radio communication method of claim 1 , further comprising:
performing an inverse Fourier fast transformation on the two or more training signals.
3 . The radio communication method of claim 2 , further comprising:
copying the two or more training signals.
4 . The radio communication method of claim 2 , further comprising:
copying the two or more training signals and adding a guard interval.
5 . The radio communication method of claim 4 , further comprising:
performing digital to analog conversion of the two or more training signals.
6 . A receiver which receives a signal from a transmitter using a single carrier, comprising:
timing adjusting circuitry configured to adjust timing of two or more training signals using a single carrier time domain correlation sequence at the time of training;
estimating circuitry configured to estimate a channel response and an IQ imbalance from the two or more training signals whose timing is adjusted by the timing adjusting circuitry;
compensating circuitry configured to compensate for the IQ imbalance estimated by the estimating circuitry; and
demodulating circuitry configured to demodulate a signal compensated by the compensating circuitry.
7 . The receiver of claim 6 , further comprising:
noise estimating circuitry configured to estimate noise in a time domain.
8 . The receiver of claim 6 , further comprising:
equalization circuitry configured to perform frequency domain equalization.
9 . The receiver of claim 7 , further comprising:
equalization circuitry configured to perform frequency domain equalization using an output from the noise estimating circuitry.
10 . The receiver of claim 6 , wherein the demodulating circuitry performs a bit recovery.