Transmission and reception signal processor and method
View Patent ↗A transmission apparatus includes a plurality of orthogonal frequency division multiplexing (OFDM) modulation signal generators, which generate a first OFDM modulation signal and a second OFDM modulation signal. The transmission apparatus also includes a transmitter that transmits the first OFDM modulation signal from a first antenna and the second OFDM modulation signal from a second antenna, in an identical frequency band. A reception apparatus is provided, which includes a plurality of antennas that receive a plurality of OFDM modulation signals; a plurality of OFDM demodulators that transform the plurality of OFDM modulation signals to a plurality of reception signals using Fourier transform; an estimator that outputs a distortion estimation signal using one or more symbols for demodulation included in the plurality of reception signals; and a demodulator that compensates for distortion of the reception signals using the distortion estimation signal and demodulates a data symbol included in the reception signals.
1. A transmission signal processor comprising:
(a) a plurality of orthogonal frequency division multiplexing (OFDM) modulation signal generators that:
(i) generate a first OFDM modulation signal by:
inserting a first symbol for demodulation in a first plurality of subcarriers at a first time and in a second plurality of sub-carriers at a second time; and
inserting a symbol, having both an in-phase (I) component and a quadrature-phase (Q) component in an I-Q plane of zero, in the second plurality of sub-carriers at the first time and in the first plurality of sub-carriers at the second time;
(ii) generate a second OFDM modulation signal by:
inserting a symbol, having both an in-phase (I) component and a quadrature-phase (Q) component in the I-Q plane of zero, in the first plurality of subcarriers at the first time and in the second plurality of sub-carriers at the second time; and
inserting a second symbol for demodulation in the second plurality of sub-carriers at the first time and in the first plurality of sub-carriers at the second time; and
(iii) generate a third OFDM modulation signal by:
inserting a third symbol for demodulation in the first plurality of sub-carriers and the second plurality of sub-carriers at a third time; and
(b) a plurality of output terminals that output either a combination of the first OFDM modulation signal and the second OFDM modulation signal or the third OFDM modulation signal, as one or more transmission signals, to a plurality of antennas, in an identical frequency band.
2. The transmission signal processor according to claim 1 , wherein the first OFDM modulation signal, the second OFDM modulation signal and the third OFDM modulation signal are comprised of data symbols.
3. The transmission signal processor according to claim 1 , wherein the first, second and third symbols for demodulation are pilot symbols.
4. The transmission signal processor according to claim 1 , wherein the first, second and third symbols for demodulation are preambles.
5. The transmission signal processor according to claim 1 , wherein the first, second and third symbols for demodulation are symbols to estimate a transmission path fluctuation.
6. The transmission signal processor according to claim 1 , wherein the first, second and third symbols for demodulation are symbols to estimate frequency offset.
7. The transmission signal processor according to claim 1 , wherein the first, second and third symbols for demodulation are comprised of phase shift keying (PSK) modulation symbols.
8. A transmission signal processing method comprising:
(a) generating a first orthogonal frequency division multiplexing (OFDM) modulation signal, utilizing a first OFDM modulation signal generator, by:
inserting a first symbol for demodulation in a first plurality of sub-carriers at a first time and in a second plurality of sub-carriers at a second time; and
inserting a symbol, having both an in-phase (I) component and a quadrature-phase (Q) component in an I-Q plane of zero, in the second plurality of sub-carriers at the first time and in the first plurality of sub-carriers at the second time; and
(b) generating a second OFDM modulation signal, utilizing a second OFDM modulation signal generator, by:
inserting a symbol, having both an in-phase (I) component and a quadrature-phase (Q) component in the I-Q plane of zero, in the first plurality of subcarriers at the first time and in the second plurality of sub-carriers at the second time; and
inserting a second symbol for demodulation in the second plurality of subcarriers at the first and in the first plurality of sub-carriers at the second time; and
(c) generating a third OFDM modulation signal, utilizing the first OFDM modulation signal generator, by:
inserting a third symbol for demodulation in the first plurality of sub-carriers and the second plurality of subcarriers at a third time; and
(d) outputting either a combination of the first OFDM modulation signal and the second OFDM modulation signal or the third OFDM modulation signal, as one or more transmission signals, to a plurality of antennas, in an identical frequency band, utilizing one or more output terminals.
9. A reception signal processor comprising:
a plurality of input terminals that receive one or more orthogonal frequency division multiplexing (OFDM) modulation signals;
a plurality of OFDM demodulators that transform the one or more OFDM modulation signals to one or more reception signals using Fourier transform;
an estimator that outputs a distortion estimation signal using at least one of symbols for demodulation included in the one or more reception signals; and
a demodulator that compensates a distortion of at least one of the one or more reception signals using the distortion estimation signal and that demodulates a data symbol included in the at least one reception signal,
(i) wherein a first OFDM modulation signal of the one or more OFDM modulation signals includes:
a first symbol for demodulation inserted in a first plurality of sub-carriers at a first time and in a second plurality of sub-carriers at a second time; and
a symbol, having both an in-phase (I) component and a quadrature-phase (Q) component in an I-Q plane of zero, inserted in the second plurality of sub-carriers at the first time and in the first plurality of sub-carriers at the second time;
(ii) a second OFDM modulation signal of the one or more OFDM modulation signals includes:
a symbol, having both an in-phase (I) component and a quadrature-phase (Q) component in the I-Q plane of zero, inserted in the first plurality of sub-carriers at the first time and in the second plurality of sub-carriers at the second time; and
a second symbol for demodulation inserted in the second plurality of sub-carriers at the first time and in the first plurality of sub-carriers at the second time; and
(iii) a third OFDM modulation signal of the one or more OFDM modulation signals includes:
a third symbol for demodulation inserted in the first plurality of sub-carriers and the second plurality of sub-carriers at a third time.
10. The reception signal processor according to claim 9 , wherein the first, second and third symbols for demodulation are pilot symbols.
11. The reception signal processor according to claim 9 , wherein the first, second and third symbols for demodulation are preambles.
12. The reception signal processor according to claim 9 , wherein the first, second and third symbols for demodulation are symbols to estimate a transmission path fluctuation.
13. The reception signal processor according to claim 9 , wherein the first, second and third symbols for demodulation are symbols to estimate frequency offset.
14. The reception signal processor according to claim 9 , wherein the first, second and third symbols for demodulation are comprised of phase shift keying (PSK) modulation symbols.
15. A reception signal processing method comprising:
receiving one or more orthogonal frequency division multiplexing (OFDM) modulation signals by a plurality of input terminals;
transforming the one or more OFDM modulation signals to one or more reception signals using Fourier transform;
outputting a distortion estimation signal using at least one of symbols for demodulation included in the one or more reception signals; and
compensating a distortion of at least one of the one or more reception signals using the distortion estimation signal and demodulating a data symbol included in the at least one reception signal,
(i) wherein a first OFDM modulation signal of the one or more OFDM modulation signals includes:
a first symbol for demodulation inserted in a first plurality of sub-carriers at a first time and in a second plurality of sub-carriers at a second time; and
a symbol, having both an in-phase (I) component and a quadrature-phase (Q) component in an I-Q plane of zero, inserted in the second plurality of sub-carriers at the first time and in the first plurality of sub-carriers at the second time;
(ii) a second OFDM modulation signal of the one or more OFDM modulation signals includes:
a symbol, having both an in-phase (I) component and a quadrature-phase (Q) component in the I-Q plane of zero, inserted in the first plurality of sub-carriers at the first time and in the second plurality of sub-carriers at the second time; and
a second symbol for demodulation inserted in the second plurality of sub-carriers at the first time and in the first plurality of sub-carriers at the second time; and
(iii) a third OFDM modulation signal of the one or more OFDM modulation signals includes:
a third symbol for demodulation inserted in the first plurality of sub-carriers and the second plurality of sub-carriers at a third time.