Multi-antenna wireless communication method and multi-antenna wireless communication device

• US 8,605,658 B2
• Filed: 12/28/2009
• Issued: 12/10/2013
• Est. Priority Date: 01/07/2009
• Status: Active Grant

• Current Assignee: Iwatsu Electric Company Limited
• Original Assignee: Iwatsu Electric Company Limited
• Inventors: Fujimoto, Atsushi
• Primary Examiner(s): Vu, Huy D
• Assistant Examiner(s): Duffy, James P
• Application Number:
  US13/143,525
• Publication Number:
  US 20110268037A1
• Time in Patent Office: 1,443 Days
• Field of Search: 375/267
• US Class Current: 370/328
• CPC Class Codes: H04B 7/043 using best eigenmode, e.g. beam forming or beam steering
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0851 using training sequences or error signal minimizing error signal H04B7/0854

Abstract

The wireless communication devices A and B determine the optimal diversity combining weight information that optimizes a diversity reception state at each antenna group A₁, A₂, . . . , A_P through two-way training signal transfer between the wireless communication devices A and B. This optimal diversity combining weight information is set to each antenna of each antenna group A₁, A₂, . . . , A_P. Wireless communication units A′, B′ perform spacial mapping of signals from antenna group A₁, A₂, . . . , A_P using MIMO technology. Communication area can be enlarged by hierarchization MIMO using the optimal diversity combining weight information.

Claims

1. A multi-antenna wireless communication method in which wireless communication is performed with MIMO (Multiple Input Multiple Output) or SIMO (Single Input Multiple Output) technology using a plurality of radios in transmitting side or in receiving side or both and in which an antenna group comprising multiple antennas is used at every transmitting/receiving circuit and each antenna group performs wireless communication with MIMO technology, the multi-antenna wireless communication method comprising:

a first step of determining diversity combining information with respect to each signal of the antennas of each antenna group that optimizes a diversity reception state at each antenna group as a value optimum in each wireless communication device through two-way training signal transfer between the wireless communication devices that perform transmission and reception;

a second step of setting the value optimum of each diversity combining information with respect to each signal of the antennas of each antenna group determined by the first step for each wireless communication device; and

a third step of enabling each wireless communication device to perform beam forming and diversity combining for a time of data transmission/reception at each antenna group in a state in which the value optimum of each diversity combining information has been set by the second step;

wherein,

in the first step, in each diversity reception in one or a plurality of times two-way training signal transfer, diversity combining information that optimizes a diversity reception state at each antenna group is obtained based on training reception information showing a receiving state of a diversity-combining received signal at each antenna group, thereafter diversity combining information is updated by the resulting diversity combining information after diversity reception, thereafter the diversity combining information updated thereby is set, and a training signal is transmitted, thereby determining a set of vectors asymptotically approaching to a set of eigenvectors with respect to a maximum eigenvalue of a correlation matrix of a channel matrix in a transfer between antenna groups of a couple of wireless communication devices that perform transmission and reception as the value optimum of diversity combining information between antenna groups of the couple of wireless communication devices.

2. A multi-antenna wireless communication device used to perform the multi-antenna wireless communication method of claim 1, the multi-antenna wireless communication device comprising:

a diversity combining information generating unit for generating diversity combining information with respect to each signal of the antennas of each antenna group;

a diversity combining information setting unit that controls an amplitude and a phase of each signal of the antennas of each antenna group based on the diversity combining information generated by the diversity combining information generating unit; and

a signal distributing/synthesizing unit that performs beam forming transmission and diversity reception at each antenna group in combination with the diversity combining information setting unit;

wherein

the diversity combining information generating unit comprises;

a for-initial-acquisition diversity combining information generating unit for generating diversity combining information for initial acquisition with respect to each signal of the antenna of each antenna group and enabling drawing from an initial state to a value optimum of diversity combining information;

a for-training diversity combining information generating unit for sequentially changing and generating diversity combining information with respect to each signal of the antennas of each antenna group during diversity reception in two-way training signal transfer between an opposite wireless communication device disposed on an opposite side of a communication link and a wireless communication device corresponding to this opposite wireless communication device; and

a diversity combining information value optimum generating unit for determining diversity combining information that optimizes a receiving state of a diversity-combining received signal based on training reception information showing a receiving state of a training signal received in a diversity reception manner in a state in which each of diversity combining information generated by the training diversity combining information generating unit has been set and for generating a value optimum of diversity combining information used for beam forming and diversity combining for a time of data transmission/reception;

wherein, in each diversity reception in one or a plurality of times two-way training signal transfer, diversity combining information that optimizes a diversity reception state is obtained based on training reception information showing a receiving state of a training signal received in a diversity reception manner in a state in which each diversity combining information generated by the diversity combining information generating unit has been set, thereafter diversity combining information is updated by the diversity combining information after diversity reception, thereafter the diversity combining information updated thereby is set, and a training signal is transmitted, thereby determining a set of vectors asymptotically approaching to a set of eigenvectors with respect to a maximum eigenvalue of a correlation matrix of a channel matrix in a transfer between antenna groups of a couple of wireless communication devices that perform transmission and reception as the value optimum of diversity combining information between antenna groups of the couple of wireless communication devices.

3. The multi-antenna wireless communication device according to claim 2, wherein

the training reception information is baseband reception IQ information of a diversity-combining received signal or both the baseband reception IQ information and reception level information.

4. The multi-antenna wireless communication device according to claim 2, wherein

the training reception information is correlation information between a diversity combining received signal and a predetermined information sequence or both the correlation information and reception level information.

5. The multi-antenna wireless communication device according to claim 2, wherein

if a value optimum of the diversity combining information has been set through an immediately previous two-way training signal transfer, the diversity combining information value optimum generating unit newly generates a value optimum of diversity combining information while using this value optimum of the diversity combining information as an initial value, and, if a value optimum of the diversity combining information has not been set, the diversity combining information value optimum generating unit newly generates a value optimum of a diversity combining information while using a random initial value.

6. The multi-antenna wireless communication device disposed on a side of a terminal according to claim 2, wherein

a first training signal is transmitted in an immediately previous two-way training signal transfer to perform beam forming and diversity combining in data transmission/reception to/from the wireless communication device disposed on a side of a base station.

7. The multi-antenna wireless communication device according to claim 2, wherein, in transmission of broadcast frames or multicast frames from the wireless communication device disposed on the side of the base station that performs wireless communication with a plurality of wireless communication devices, a same frame is transmitted a plurality of times by using a plurality of pieces of diversity combining information that differ from each other.

8. The multi-antenna wireless communication device according to claim 2, wherein, in transmission of broadcast frames or multicast frames from the wireless communication device disposed on the side of the base station that performs wireless communication with a plurality of wireless communication devices, each of the broadcast frames or each of the multicast frames is transmitted to each of the plurality of wireless communication devices by use of a value optimum of the diversity combining information obtained through a two-way training signal transfer.

9. The multi-antenna wireless communication device according to claim 2, wherein, in the wireless communication device disposed on a base station that performs wireless communication with a plurality of wireless communication device, a diversity combining information value optimum storing unit is provided for storing a value optimum of the diversity combining information obtained through a two-way training signal transfer, for each wireless communication device disposed on the side of the terminal that performs wireless communication with the base station, and, before data transmission/reception to and from a terminal-side wireless communication device disposed on a side of a terminal, a value optimum of the diversity combining information with respect to this terminal-side wireless communication device, that is held by the diversity combining information value optimum storing unit, is set by the diversity combining information setting unit.

10. The multi-antenna wireless communication device according to claim 2, wherein

the diversity combining information setting unit and the signal distributing/synthesizing unit operate in an RF band, and multi-antenna beam forming transmission and multi-antenna diversity reception are performed by use of a single transmission/reception system.

11. A multi-antenna wireless communication method in which wireless communication is performed with MIMO (Multiple Input Multiple Output) or SIMO (Single Input Multiple Output) technology using a plurality of radios in transmitting side or in receiving side or both and in which an antenna group comprising multiple antennas is used at every transmitting/receiving circuit and each antenna group performs wireless communication with MIMO technology, the multi-antenna wireless communication method comprising:

a first step of determining diversity combining information with respect to each signal of the antennas of each antenna group that optimizes a diversity reception state at each antenna group as a value optimum in each wireless communication device through one or a plurality of times two-way training signal transfer between the wireless communication devices that perform transmission and reception;

a second step of setting the value optimum of each diversity combining information with respect to each signal of the antennas of each antenna group determined by the first step for each wireless communication device; and

a third step of enabling each wireless communication device to perform beam forming and diversity combining for a time of data transmission/reception at each antenna group in a state in which the value optimum of each diversity combining information has been set by the second step;

wherein

the training signal is composed of a plurality of training sub-signals, and, in the first step, in diversity reception of the training sub-signals, one piece of diversity combining information with respect to each signal of the antennas of the antenna group of the wireless communication devices is sequentially changed, thereafter diversity combining information with respect to each signal of the antennas of the antenna group is updated by diversity combining information having a more excellent receiving state of a diversity-combining received signal before and after a sequential changing operation of the diversity combining information, thereafter the diversity combining information updated thereby is set, and a training signal is transmitted, thereby determining a set of vectors asymptotically approaching to a set of eigenvectors with respect to a maximum eigenvalue of a correlation matrix of a channel matrix in a transfer between antenna groups of a couple of wireless communication devices that perform transmission and reception as the value optimum of diversity combining information between antenna groups of the couple of wireless communication devices.

12. A multi-antenna wireless communication device used to perform the multi-antenna wireless communication method of claim 11, the multi-antenna wireless communication device comprising:

a diversity combining information generating unit for generating diversity combining information with respect to each signal of the antennas of each antenna group;

a diversity combining information setting unit that controls an amplitude and a phase of each signal of the antennas of each antenna group based on the diversity combining information generated by the diversity combining information generating unit; and

a signal distributing/synthesizing unit that performs beam forming transmission and diversity reception at each antenna group in combination with the diversity combining information setting unit;

wherein

the diversity combining information generating unit comprises;

a for-initial-acquisition diversity combining information generating unit for generating diversity combining information for initial acquisition with respect to each signal of the antenna of each antenna group and enabling drawing from an initial state to a value optimum of diversity combining information;

a for-training diversity combining information generating unit for sequentially changing and generating diversity combining information with respect to each signal of the antennas of each antenna group during diversity reception in one or a plurality of times two-way training signal transfer between an opposite wireless communication device disposed on an opposite side of a communication link and a wireless communication device corresponding to this opposite wireless communication device;

a reception-state determining unit that determines a diversity reception state in each setting based on training reception information showing a receiving state of a training signal received in a diversity reception manner in a state in which each piece of diversity combining information generated by the diversity combining information generating unit has been set; and

a diversity combining information value optimum generating unit for determining diversity combining information that optimizes a diversity reception state determined by the reception-state determining unit as a value optimum of the diversity combining information and for generating a value optimum of diversity combining information used for beam forming and diversity combining at a time of data transmission/reception;

wherein

the training signal is composed of a plurality of training sub-signals, and, in diversity reception of the training sub-signals, one piece of diversity combining information with respect to each signal of the antennas of each antenna group of the wireless communication devices is sequentially changed, and thereafter diversity combining information with respect to each signal of the antennas of each antenna group is updated by diversity combining information having a more excellent receiving state of a diversity-combining received signal before and after a sequential changing operation of the diversity combining information, thereafter the diversity combining information updated thereby is set, and a training signal is transmitted, thereby determining a set of vectors asymptotically approaching to a set of eigenvectors with respect to a maximum eigenvalue of a correlation matrix of a channel matrix in a transfer between antenna groups of a couple of wireless communication devices that perform transmission and reception as the value optimum of diversity combining information between antenna groups of the couple of wireless communication devices.

13. The multi-antenna wireless communication device according to claim 12, wherein

the diversity combining information is 1-bit information, and the diversity combining information generating unit generates diversity combining information with respect to each signal of the antennas of each antenna group while sequentially subjecting the diversity combining information to phase inversion, and the reception-state determining unit makes a comparison between reception level information as the training reception information obtained before and after performing the phase inversion, and determines a diversity reception state at each antenna group from this comparison, and the diversity combining information value optimum generating unit generates a value optimum of the diversity combining information in the antennas of each antenna group based on the diversity reception state determined by the reception-state determining unit.

14. The multi-antenna wireless communication device according to claim 12, wherein

the reception-state determining unit determines a diversity reception state at each antenna group while using a diversity-combining received signal level or a gain of an AGC amplifier as an indicator.

15. A multi-antenna wireless communication method in which wireless communication is performed with MIMO (Multiple Input Multiple Output) or SIMO (Single Input Multiple Output) technology using a plurality of radios in transmitting side or in receiving side or both and in which an antenna group comprising multiple antennas is used at every transmitting/receiving circuit and each antenna group performs wireless communication with MIMO technology, the multi-antenna wireless communication method comprising:

a first step of determining diversity combining information with respect to each signal of the antennas of each antenna group that optimizes a diversity reception state at each antenna group as a value optimum in each wireless communication device through one or a plurality of times two-way training signal transfer between the wireless communication devices that perform transmission and reception;

a second step of setting the value optimum of each diversity combining information with respect to each signal of the antennas of each antenna group determined by the first step for each wireless communication device; and

a third step of enabling each wireless communication device to perform beam forming and diversity combining for a time of data transmission/reception at each antenna group in a state in which the value optimum of each diversity combining information has been set by the second step;

wherein

the training signal is composed of a plurality of training sub-signals, and,

in the first step, in diversity reception of the plurality of training sub-signals, diversity combining information with respect to each signal of the antennas of the antenna group of the wireless communication devices is sequentially changed, thereafter diversity combining information that optimizes a receiving state of a diversity-combining received signal at each antenna group is determined based on training reception information showing a receiving state corresponding to each of the diversity combining information, thereafter diversity combining information with respect to each signal of the antennas of each antenna group is updated by the resulting diversity combining information after diversity reception, thereafter the diversity combining information updated thereby is set, and a training signal is transmitted, thereby determining a set of vectors asymptotically approaching to a set of eigenvectors with respect to a maximum eigenvalue of a correlation matrix of a channel matrix in a transfer between antenna groups of a couple of wireless communication devices that perform transmission and reception as the value optimum of diversity combining information between antenna groups of the couple of wireless communication devices.

16. A multi-antenna wireless communication device used to perform the multi-antenna wireless communication method of claim 15, the multi-antenna wireless communication device comprising:

a diversity combining information generating unit for generating diversity combining information with respect to each signal of the antennas of each antenna group;

a diversity combining information setting unit that controls an amplitude and a phase of each signal of the antennas of each antenna group based on the diversity combining information generated by the diversity combining information generating unit; and

a signal distributing/synthesizing unit that performs beam forming transmission and diversity reception at each antenna group in combination with the diversity combining information setting unit;

wherein

the diversity combining information generating unit comprises;

a for-initial-acquisition diversity combining information generating unit for generating diversity combining information for initial acquisition with respect to each signal of the antenna of each antenna group and enabling drawing from an initial state to a value optimum of diversity combining information;

a for-training diversity combining information generating unit for sequentially changing and generating diversity combining information with respect to each signal of the antennas of each antenna group during diversity reception in one or a plurality of times two-way training signal transfer between an opposite wireless communication device disposed on an opposite side of a communication link and a wireless communication device corresponding to this opposite wireless communication device;

a training receiving state holding unit that holds training reception information showing a receiving state of a training signal received in a diversity reception manner in a state in which diversity combining information generated by the diversity combining information generating unit has been set; and

a diversity combining information value optimum generating unit for determining diversity combining information that optimizes a diversity reception state based on the training reception information held by the training receiving state holding unit as a value optimum of the diversity combining information and for generating a value optimum of diversity combining information used for beam forming and diversity combining at a time of data transmission/reception;

wherein

the training signal is composed of a plurality of training sub-signals, and, in diversity reception of the training sub-signals, diversity combining information with respect to each signal of the antennas of each antenna group of the wireless communication devices is sequentially changed, thereafter training reception information corresponding to each piece of diversity combining information is stored in the training reception information holding unit, thereafter diversity combining information that optimizes a receiving state of a diversity-combining received signal is determined based on information held in the training reception information holding unit, thereafter diversity combining information is updated by the diversity combining information, thereafter the diversity combining information updated thereby is set, and a training signal is transmitted, thereby determining a set of vectors asymptotically approaching to a set of eigenvectors with respect to a maximum eigenvalue of a correlation matrix of a channel matrix in a transfer between antenna groups of a couple of wireless communication devices that perform transmission and reception as the value optimum of diversity combining information between antenna groups of the couple of wireless communication devices.

17. The multi-antenna wireless communication device according to claim 16, wherein

the diversity combining information is n-bit information (n is a natural number of 2 or greater), and the diversity combining information generating unit generates diversity combining information with respect to each signal of the antennas of each antenna group while sequentially subjecting the diversity combining information to phase inversion, and the training receiving state holding unit holds baseband reception IQ information or both the baseband reception IQ information and reception level information as the training reception information showing receiving state obtained before and after performing the phase inversion, and the diversity combining information value optimum generating unit generates a value optimum of the diversity combining information in the antennas of each antenna group based on the training reception information held by the training receiving state holding unit.

18. The multi-antenna wireless communication device according to claim 16, wherein

the training signal contains a plurality of frames or symbols as the training sub-signals, and

the diversity combining information value optimum generating unit determines a diversity reception state while using an amplitude of a baseband IQ signal or an IF signal of each frame or each symbol at each antenna group as an indicator.

19. A multi-antenna wireless communication method in which wireless communication is performed with MIMO (Multiple Input Multiple Output) or SIMO (Single Input Multiple Output) technology using a plurality of radios in transmitting side or in receiving side or both and in which an antenna group comprising multiple antennas is used at every transmitting/receiving circuit and each antenna group performs wireless communication with MIMO technology, the multi-antenna wireless communication method comprising:

a first step of determining diversity combining information with respect to each signal of the antennas of each antenna group that optimizes a diversity reception state at each antenna group as a value optimum in each wireless communication device through one or a plurality of times two-way training signal transfer between the wireless communication devices that perform transmission and reception;

a second step of setting the value optimum of each diversity combining information with respect to each signal of the antennas of each antenna group determined by the first step for each wireless communication device; and

a third step of enabling each wireless communication device to perform beam forming and diversity combining for a time of data transmission/reception at each antenna group in a state in which the value optimum of each diversity combining information has been set by the second step;

wherein

the training signal is composed of a plurality of training sub-signals, and, in the first step, in diversity reception of the plurality of training sub-signals, diversity combining information with respect to each signal of the antennas of the antenna group of the wireless communication devices is sequentially changed, thereafter diversity combining complex weight information that optimizes a receiving state of a diversity-combining received signal at each antenna group is determined based on training reception information showing a receiving state corresponding to each of the diversity combining information, thereafter diversity combining information with respect to each signal of the antennas of each antenna group is updated by the resulting diversity combining complex weight information after diversity reception, thereafter the diversity combining information updated thereby is set, and a training signal is transmitted, thereby determining a set of vectors asymptotically approaching to a set of eigenvectors with respect to a maximum eigenvalue of a correlation matrix of a channel matrix in a transfer between antenna groups of a couple of wireless communication devices that perform transmission and reception as the value optimum of diversity combining information between antenna groups of the couple of wireless communication devices.

20. A multi-antenna wireless communication device used to perform the multi-antenna wireless communication method of claim 19, the multi-antenna wireless communication device comprising:

a diversity combining information generating unit for generating diversity combining information with respect to each signal of the antennas of each antenna group;

a diversity combining information setting unit that controls an amplitude and a phase of each signal of the antennas of each antenna group based on the diversity combining information generated by the diversity combining information generating unit; and

a signal distributing/synthesizing unit that performs beam forming transmission and diversity reception at each antenna group in combination with the diversity combining information setting unit;

wherein

the diversity combining information generating unit comprises;

a for-initial-acquisition diversity combining information generating unit for generating diversity combining information for initial acquisition with respect to each signal of the antenna of each antenna group and enabling drawing from an initial state to a value optimum of diversity combining information;

a for-training diversity combining information generating unit for sequentially changing and generating diversity combining information with respect to each signal of the antennas of each antenna group during diversity reception in one or a plurality of times two-way training signal transfer between an opposite wireless communication device disposed on an opposite side of a communication link and a wireless communication device corresponding to this opposite wireless communication device;

a training reception information holding unit for holding training reception information showing a receiving state of a training signal received in a diversity reception manner in a state in which each piece of diversity combining information generated by the diversity combining information generating unit has been set; and

a diversity combining information value optimum generating unit for determining diversity combining complex weight information that optimizes a receiving state of a diversity-combining received signal at each antenna group based on training reception information held by the training reception information holding unit as a value optimum of diversity combining information and for generating a value optimum of diversity combining information used for beam forming and diversity combining at each antenna group for a time of data transmission/reception;

wherein

the training signal is composed of a plurality of training sub-signals,

in each diversity reception in a plurality of times two-way training signal transfer, diversity combining information with respect to each signal of the antennas of each antenna group of the wireless communication devices are sequentially changed, thereafter training reception information corresponding to each diversity combining information is stored in the training reception information holding unit, thereafter diversity combining complex weight information that optimizes a receiving state of a diversity-combining received signal is determined based on information held by the training reception information holding unit, thereafter diversity combining information is updated by diversity combining complex weight information after each diversity reception, thereafter the diversity combining information updated thereby is set, and a training signal is transmitted, thereby determining a set of vectors asymptotically approaching to a set of eigenvectors with respect to a maximum eigenvalue of a correlation matrix of a channel matrix in a transfer between antenna groups of a couple of wireless communication devices that perform transmission and reception as the value optimum of diversity combining information between antenna groups of the couple of wireless communication devices.