IP Library › Granted Patent US 9,363,124
Granted Patent B2
US 9,363,124 · App. 14/845,132 · Granted Jun 7, 2016

Transmission and reception signal processor and method

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Quick Facts
Patent No.
US 9,363,124
App. No.
14/845,132
Granted
Jun 7, 2016
Kind
B2
Abstract

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.

Claims (60)

1. A transmission apparatus 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 transmitters that transmit either a combination of the first OFDM modulation signal and the second OFDM modulation signal, from respective different antennas, in an identical frequency band, or the third OFDM modulation signal, from a plurality of antennas, in an identical frequency band.

2. The transmission apparatus 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 apparatus according to claim 1 , wherein the first, second and third symbols for demodulation are pilot symbols.

4. The transmission apparatus according to claim 1 , wherein the first, second and third symbols for demodulation are preambles.

5. The transmission apparatus according to claim 1 , wherein the first, second and third symbols for demodulation are symbols to estimate a transmission path fluctuation.

6. The transmission apparatus according to claim 1 , wherein the first, second and third symbols for demodulation are symbols to estimate frequency offset.

7. The transmission apparatus 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 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) transmitting either a combination of the first OFDM modulation signal and the second OFDM modulation signal, from respective different antennas, in an identical frequency band, or the third OFDM modulation signal, from a plurality of antennas, in an identical frequency band.

9. A reception apparatus comprising:

a plurality of receivers that receive a plurality of orthogonal frequency division multiplexing (OFDM) modulation signals;

a plurality of OFDM demodulators that transform the plurality of 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,

wherein the plurality of OFDM modulation signals include either a combination of a first OFDM modulation signal and a second OFDM modulation signal, transmitted from respective different antennas, in an identical frequency band, or a third OFDM modulation signal, transmitted from a plurality of antennas, in an identical frequency band,

(i) the first OFDM modulation signal 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) the second OFDM modulation signal 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) the third OFDM modulation signal 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 apparatus according to claim 9 , wherein the first, second and third symbols for demodulation are pilot symbols.

11. The reception apparatus according to claim 9 , wherein the first, second and third symbols for demodulation are preambles.

12. The reception apparatus according to claim 9 , wherein the first, second and third symbols for demodulation are symbols to estimate a transmission path fluctuation.

13. The reception apparatus according to claim 9 , wherein the first, second and third symbols for demodulation are symbols to estimate frequency offset.

14. The reception apparatus 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 method comprising:

receiving a plurality of orthogonal frequency division multiplexing (OFDM) modulation signals by a plurality of receivers;

transforming the plurality of 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,

wherein the plurality of OFDM modulation signals include either a combination of a first OFDM modulation signal and a second OFDM modulation signal, transmitted from respective different antennas, in an identical frequency band, or a third OFDM modulation signal, transmitted from a plurality of antennas, in an identical frequency band,

(i) the first OFDM modulation signal 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) the second OFDM modulation signal 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) the third OFDM modulation signal 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.