Radio communication device and radio communication method

• US 6,493,397 B1
• Filed: 06/18/1999
• Issued: 12/10/2002
• Est. Priority Date: 10/20/1997
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Hiramatsu, Katsuhiko, Takahashi, Hideyuki
• Primary Examiner(s): VO, DON NGUYEN
• Application Number:
  US09/319,941
• Time in Patent Office: 1,271 Days
• Field of Search: 375/267, 375/285, 375/347, 375/344, 375/371, 375/346
• US Class Current: 375/285
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 2027/0032 at baseband and passband
• CPC Class Codes: H04L 2027/0055 single phase
• CPC Class Codes: H04L 2027/0057 quadrature phase
• CPC Class Codes: H04L 2027/0065 Frequency error detectors H04L2027/0067 takes precedence
• CPC Class Codes: H04L 2027/0093 Intermittant signals
• CPC Class Codes: H04L 27/2332 using a non-coherent carrier

Abstract

A compensator eliminates frequency offset contained in digital-converted signals output from A/D converters. A weighting coefficient calculator, a complex multiplier and an adder eliminate an interference component from a signal from which frequency offset is eliminated. A differential coherent detector demodulates a signal from which the interference component is eliminated. A decoder decodes the demodulated signal, while a frequency offset estimator estimates frequency offset using the demodulated signal and a known symbol.

Claims

1. A radio communication apparatus comprising:

a compensation device that compensates frequency offset of each of signals received at a plurality of antennas;

an interference component suppression device that suppresses an interference component of an output signal from the compensation device;

a differential coherent detection device that performs deferential coherent detection of an output signal from the interference component suppression device to output a demodulated signal;

a decoding device that decodes said demodulated signal to capture desired data; and

a frequency offset estimation device that estimates frequency offset using said demodulated signal.

2. The radio communication apparatus according to claim 1, wherein the compensation device controls a digital-converted signal using the frequency offset estimation result.

3. The radio communication apparatus according to claim 2, wherein the compensation device temporarily stores the digital-converted signal at a buffer, and compensates the frequency offset on a signal of a current slot stored in the buffer using a frequency offset amount of the current slot estimated by the frequency offset estimation device.

4. The radio communication apparatus according to claim 1, wherein the interference component suppression device comprising:

a weighting coefficient calculation device that calculates an optimal weighting coefficient for each of output signals from the compensation device based on a known symbol;

a complex multiplication device that multiplies each of said output signals from the compensation device by the optimal weighting coefficient; and

an adding device that adds an output signal from the complex multiplication device.

5. The radio communication apparatus according to claim 4, wherein the weighting coefficient calculation device stores the calculated optimal weighting coefficient, and the complex multiplication device multiplies a signal of a current slot output from the compensation device by a weighting coefficient stored at a buffer.

6. The radio communication apparatus according to claim 5, further comprising a decision device that decides sizes of errors of a demodulated signal of the current slot and a demodulated signal stored at a buffer and outputs a demodulated signal having smaller error to the decoding device.

7. The radio communication apparatus according to claim 1, wherein the compensation device controls a received analog signal using the frequency offset estimation result.

8. The radio communication apparatus according to claim 1, wherein the compensation device controls a received analog signal using the frequency offset estimation result to roughly compensate the frequency offset, and controls a digital-converted signal to finely compensate the frequency offset.

9. A communication terminal apparatus capturing desired data from a received signal using a radio communication apparatus according to claim 1.

10. A base station apparatus capturing desired data from a received signal using a radio communication apparatus according to claim 1.

11. A radio communication method comprising:

compensating frequency offset of each of signals received at a plurality of antennas;

suppressing an interference component of a signal in which the frequency offset is compensated;

performing deferential coherent detection of a signal in which the interference component is suppressed to demodulate the signal; and

decoding the demodulated signal to capture desired data, while estimating frequency offset using said demodulated signal.

12. The radio communication method according to claim 11, further comprising controlling a digital-converted signal using the frequency offset estimation result.

13. The radio communication method according to claim 12, further comprising temporarily storing a digital-converted signal of each of signals received at a plurality of antennas at a buffer, while estimating frequency offset using the digital-converted signal;

and

compensating the frequency offset of a signal of a current slot stored at the buffer using the estimated frequency offset amount of the current slot.

14. The radio communication method according to claim 11, further comprising:

calculating an optimal weighting coefficient for each of compensated signals based on a known symbol;

multiplying each of said compensated signals by the optimal weighting coefficient to suppress an interference component; and

adding each signal.

15. The radio communication method according to claim 14, further comprising:

storing the calculated optimal weighting coefficient at a buffer; and

multiplying the compensated signal of a current slot by a weighting coefficient stored at the buffer.

16. The radio communication apparatus according to claim 15, further comprising:

deciding sizes of errors of a demodulated signal of the current slot and a demodulated signal stored at the buffer to decode a demodulated signal having smaller error.

17. The radio communication method according to claim 11, further comprising controlling a received analog signal using the frequency offset estimation result.

18. The radio communication method according to claim 11, further comprising:

controlling a received analog signal using the frequency offset estimation result to roughly compensate the frequency offset; and

controlling a digital-converted signal to finely compensate the frequency offset.