Transmitter apparatus, receiver apparatus, and radio communication system

• US 7,565,114 B2
• Filed: 07/16/2004
• Issued: 07/21/2009
• Est. Priority Date: 07/16/2003
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Ito, Takumi, Yoshida, Shousei
• Primary Examiner(s): Anderson; Matthew D
• Assistant Examiner(s): Aminzay; Shaima Q
• Application Number:
  US10/564,552
• Publication Number:
  US 20060166625A1
• Time in Patent Office: 1,831 Days
• Field of Search: 455/69, 455/63.1, 455/450, 455/562.1, 455/13.4, 455101-104, 455/114.2, 4551151-1153, 4551271-1275, 370/329, 370/334, 375/260, 375/267, 375/295, 375/299, 375/316
• US Class Current: 455/69
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04

Abstract

An SINR estimating unit of a receiver apparatus measures first and second demodulated signals to calculate SINR (ratio of signal power to sum of interference power and noise power) for each signal sequence. A transmission parameter deciding unit decides, based on the SINR, a transmission parameter used by a transmitter apparatus for controlling the transmission for each signal sequence, and then feeds the decided transmission parameter back to the transmitter apparatus. First and second mapping units of the transmitter apparatus controls, based on the transmission parameters as fed back, the modulation level for each signal sequence.

Claims

1. A receiver apparatus for receiving, by a plurality of receiver antennas, transmission signals transmitted from a transmitter apparatus by a plurality of transmitter antennas in a parallel manner and for estimating a channel matrix for causing the transmission signals to be related to received signals to demodulate the received signals based upon said channel matrix;

the receiver apparatus comprising;

calculation means for calculating a physical amount so as to estimate a radio line quality with respect to each of signal series based upon only said channel matrix;

determination means for evaluating the radio line quality based upon the physical amount calculated by said calculation means so as to determine a transmission parameter in a next transmission operation by said transmitter apparatus with respect to each of the signal series;

transmission means for transmitting the transmission parameter determined by said determination means to said transmitter apparatus; and

detection means for detecting a change in the transmission parameter from the received signals with respect to each of the signal series,

wherein the transmission parameter is a modulation level in mapping.

2. A receiver apparatus as claimed in claim 1 wherein,

said physical amount is a signal-to-noise ratio (SNR) of said demodulated signals.

3. A receiver apparatus as claimed in claim 1 wherein,

said physical amount corresponds to a sum of signal-to-noise ratios (SNRs) of signals which are detected by said plurality of receiver antennas when it is assumed that said plurality of transmitter antennas separately transmit signals.

4. A receiver apparatus as claimed in claim 3 wherein,

said physical amount corresponds to a sum of one, or a plurality of said SNRs having larger values.

5. A receiver apparatus as claimed in claim 1, wherein said estimates the channel matrix using a pilot signal output by said transmitter apparatus, and wherein no information obtained by demodulating the received signals is utilized by said calculation means in calculating the physical amount.

6. A radio communication system comprising a transmitter apparatus for transmitting transmission signals by a plurality of transmitter antennas in a parallel manner;

and a receiver apparatus for receiving said transmission signals by a plurality of receiver antennas, a for estimating a channel matrix for causing the transmission signals to be related to received signals to demodulate the received signals based upon said channel matrix;

wherein

said receiver apparatus comprises;

calculation means for calculating a physical amount so as to estimate a radio line quality with respect to each of signal series based upon only said channel matrix;

determination means for evaluating the radio line quality based upon the physical amount calculated by said calculation means so as to determine a transmission parameter in a next transmission operation by said transmitter apparatus with respect to each of the signal series;

transmission means for transmitting the transmission parameter determined by said determination means to said transmitter apparatus; and

detection means for detecting a change in the transmission parameter from the received signals with respect to each of the signal series; and

wherein,

said transmitter apparatus comprises;

reception means for receiving said transmission parameter transmitted by said determining means; and

means for controlling the transmission operation with respect to each of the signal series based upon said transmission parameter received by said reception means,

wherein the transmission parameter is a modulation level in mapping.

7. A radio communication system as claimed in claim 6 wherein,

said physical amount is a signal-to-noise ratio (SNR) of said demodulated signals.

8. A radio communication system as claimed in claim 6 wherein,

said physical amount corresponds to a sum of signal-to-noise ratios (SNRs) of signals which are detected by said plurality of receiver antennas when it is assumed that said plurality of transmitter antennas separately transmit signals.

9. A radio communication system as claimed in claim 8 wherein,

said physical amount corresponds to a sum of one, or a plurality of said SNRs having larger values.

10. A radio communication system as claimed in claim 6, wherein said estimates the channel matrix using a pilot signal output by said transmitter apparatus, and wherein no information obtained by demodulating the received signals is utilized by said calculation means in calculating the physical amount.

11. A transmitter apparatus for transmitting data by a plurality of transmitter antennas in a parallel manner to a receiver apparatus for receiving by a plurality of receiver antennas, said transmitter apparatus being used in a radio communication system in which a channel matrix for causing the signal transmitted by said transmitter apparatus to be related to said signal detected by said receiver apparatus becomes identical to a channel matrix for causing the signal transmitted by said receiver apparatus to be related to said signal detected by said transmitter apparatus;

wherein,

said transmitter apparatus comprises;

estimation means for estimating said channel matrix;

calculation means for calculating a physical amount so as to estimate a radio line quality with respect to each of signal series based upon only said channel matrix;

determination means for evaluating the radio line quality based upon the physical amount calculated by said calculation means so as to determine a transmission parameter in a next transmission operation with respect to each of the signal series based upon the transmission parameter determined by said determination means,

wherein the transmission parameter is a modulation level in mapping.

12. A transmitter apparatus as claimed in claim 11 wherein,

said physical amount corresponds to a signal-to-noise ratio (SNR) of demodulated signals of said receiver apparatus.

13. A transmitter apparatus as claimed in claim 11 wherein,

said physical amount corresponds to a sum of signal-to-noise ratios (SNRs) of signals which are detected by said plurality of receiver antennas when it is assumed that said plurality of transmitter antennas separately transmit signals.

14. A transmitter apparatus as claimed in claim 13 wherein,

said physical amount corresponds to a sum of one, or a plurality of said SNRs having larger values.

15. A transmitter apparatus as claimed in claim 11, wherein said estimates the channel matrix using a pilot signal output by said transmitter apparatus, and wherein no information obtained by demodulating the received signals is utilized by said calculation means in calculating the physical amount.

16. A radio communication system comprising a transmitter apparatus for transmitting transmission signals by a plurality of transmitter antennas in a parallel manner;

and a receiver apparatus for receiving said transmission signals by a plurality of receiver antennas, a channel matrix for causing the signal transmitted by said transmitter apparatus to be related to said signal detected by said receiver apparatus becomes identical to a channel matrix for causing the signal transmitted by said receiver apparatus to be related to said signal detected by said transmitter apparatus;

wherein,

said transmitter apparatus comprises;

estimation means for estimating said channel matrix;

calculation means for calculating a physical amount so as to estimate a radio line quality with respect to each of signal series based upon only said channel matrix;

determination means for evaluating the radio line quality based upon the physical amount calculated by said calculation means so as to determine a transmission parameter in a next transmission operation with respect to each of signal series; and

means for controlling the transmission operation with respect to each of the signal series based upon the transmission parameter determined by said determination means; and

wherein,

said receiver apparatus comprises;

means for detecting a change in said transmission parameter from the signals received from said transmitter apparatus with respect to each of signal series,

wherein the transmission parameter is a modulation level in mapping.

17. A radio communication system as claimed in claim 16 wherein,

said physical amount corresponds to a signal-to-noise ratio (SNR) of demodulated signals of said receiver apparatus.

18. A radio communication system as claimed in claim 16 wherein,

said physical amount corresponds to a sum of signal-to-noise ratios (SNRs) of signals which are detected by said plurality of receiver antennas when it is assumed that said plurality of transmitter antennas separately transmit signals.

19. A radio communication system as claimed in claim 18 wherein,

said physical amount corresponds to a sum of one, or a plurality of said SNRs having larger values.

20. A radio communication system as claimed in claim 16, wherein said estimates the channel matrix using a pilot signal output by said transmitter apparatus, and wherein no information obtained by demodulating the received signals is utilized by said calculation means in calculating the physical amount.