TRANSMISSION METHOD, TRANSMITTER, AND RECEIVER FOR MULTI ANTENNA WIRELESS COMMUNICATION SYSTEM

• US 20080037680A1
• Filed: 08/14/2007
• Published: 02/14/2008
• Est. Priority Date: 08/14/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: SAKATA, Ren, Akita, Koji
• Granted Patent: US 8,116,398 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/06 at the transmitting station
• CPC Class Codes: H04B 7/0613 using simultaneous transmission H04B7/0686 takes precedence
• CPC Class Codes: H04B 7/0671 using different delays between antennas
• CPC Class Codes: H04B 7/0684 using different training sequences per antenna
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only

Abstract

A transmitter includes first generator to generate pilot source signal by modulating pilot sequence, second generator to generate data source signal with time length longer than that of pilot source signal by modulating data sequence, first cyclic shifter to perform cyclic shift of first shift amount to pilot source signal to generate first pilot signal, second cyclic shifter to performs cyclic shift of second shift amount to data source signal to generate first data signal, third cyclic shifter to perform cyclic shift of third shift amount to pilot source signal to generate second pilot signal, fourth cyclic shifter to perform cyclic shift of fourth shift amount to data source signal to generate second data signal, first transmit antenna to transmit first pilot signal and first data signal, and second transmit antenna to transmit second pilot signal and second data signal.

Claims

1. Transmission method comprising:

generating a pilot source signal by modulating a pilot sequence;

generating a data source signal with a time length longer than that of the pilot source signal by modulating a data sequence;

performing a cyclic shift of a first sift amount to the pilot source signal to generate a first pilot signal;

performing a cyclic shift of a second sift amount to the data source signal to generate a first data signal;

performing a cyclic shift of a third sift amount to the pilot source signal to generate a second pilot signal;

performing a cyclic shift of a fourth shift amount to the data source signal to generate s second data signal;

transmitting the first pilot signal and the first data signal from a first transmit antenna; and

transmitting the second pilot signal and the second data signal from a second transmit antenna.

2. The method according to claim 1, wherein a difference between the second shift amount and the fourth shift amount is a half of the time length of the data source signal.

3. A transmitter comprising:

a first generator which generates a pilot source signal by modulating a pilot sequence;

a second generator which generates a data source signal with a time length longer than that of the pilot source signal by modulating a data sequence;

a first cyclic shifter which performs a cyclic shift of a first shift amount to the pilot source signal to generate a first pilot signal;

a second cyclic shifter which performs a cyclic shift of a second shift amount to the data source signal to generate a first data signal;

a third cyclic shifter which performs a cyclic shift of a third shift amount to the pilot source signal to generate a second pilot signal;

a fourth cyclic shifter which performs a cyclic shift of a fourth shift amount to the data source signal to generate a second data signal;

a first transmit antenna which transmits the first pilot signal and the first data signal; and

a second transmit antenna which transmits the second pilot signal and the second data signal.

4. The transmitter according to claim 3, wherein a difference between the second shift amount and the fourth shift amount is a half of the time length of the data source signal.

9. A receiver comprising:

a receive antenna which receives a signal including the first pilot signal, the first data signal, the second pilot signal and the second data signal transmitted from the transmitter according to claim 3 to obtain a received signal;

a correlator which performs correlation calculation between a received pilot signal with the first pilot signal and the second pilot signal mixed therein and a pilot source signal to obtain a first impulse response in a first channel between the first transmit antenna and the receive antenna and a second impulse response in a second channel between the second transmit antenna and the receive antenna;

a first delay unit which performs a delay equal to a difference between the second sift amount and the first sift amount in response to the first impulse response to obtain an impulse response for first compensation;

a second delay unit which performs a delay equal to a difference between the fourth sift amount and the third sift amount in response to the second impulse response to obtain an impulse response for second compensation; and

a compensator which compensates distortion in a received data signal in which the first data signal and the second data signal are mixed using summing the first impulse response and the second impulse response.

10. The receiver according to claim 9, wherein the correlator includes a matched filter having a sequence in which the pilot source signal is repeated twice and which is used as a tap coefficient.

5. A transmission method comprising:

generating a pilot source signal by modulating a pilot sequence;

generating a data source signal longer than the that of the pilot source signal in time length by modulating a data sequence;

generating a first pilot signal from the pilot source signal;

generating a first data signal from the data source signal;

performing a cyclic shift of a first shift amount to the pilot source signal to generate a second pilot signal;

performing a cyclic shift of a second shift amount differing from the first shift amount to the data source signal to generate a second data signal,

transmitting the first pilot signal and the first data signal from the first transmit antenna; and

transmitting the second pilot signal and the second data signal from a second transmit antenna.

6. The transmission method according to claim 5, wherein the second shift amount is a half of the time length of the data source signal.

7. A transmitter comprising:

a first generator which generates a pilot source signal by modulating a pilot sequence;

a second generator which generates a data source signal longer than the pilot source signal in time length by modulating a data sequence;

a third generator which generates a first pilot signal from the pilot source signal;

a fourth generator which generates a first data signal from the data source signal;

a first cyclic shifter which performs a cyclic shift of a first shift amount to the pilot source signal to generate a second pilot signal;

a second cyclic shifter which performs a cyclic shift of a second shift amount differing from the first shift amount to the data source signal to generate a second data signal;

a first transmit antenna which transmits the first pilot signal and the first data source signal; and

a second transmit antenna which transmits the second pilot signal and the second data signal.

8. The transmitter according to claim 7, wherein the second shift amount is a half of the time length of the data source signal.

11. The receiver comprising:

a receive antenna which receives a signal including the first pilot signal, the first data signal, the second pilot signal and the second data signal transmitted from the transmitter according to claim 7 to obtain a received signal;

a correlator which performs correlation calculation between a received pilot signal with the first and the second pilot signals mixed therein and a pilot source signal to obtain a first impulse response in a first channel between the first transmit antenna and the receive antenna and a second impulse response in a second channel between the second transmit antenna and the receive antenna;

a first delay unit which performs a delay equal to a difference between the second sift amount and the first sift amount in response to the second impulse response to obtain an compensation impulse response; and

a compensator which compensates distortion in a received data signal in which the first data signal and the second data signal are mixed using summing the first impulse response and the compensation impulse response.

12. The receiver according to claim 11, wherein the correlator includes a matched filter having a sequence in which the pilot source signal is repeated twice and which is used as a tap coefficient.