FreshPatents.com Logo
stats FreshPatents Stats
3 views for this patent on FreshPatents.com
2010: 3 views
Updated: March 31 2014
newTOP 200 Companies filing patents this week


    Free Services  

  • MONITOR KEYWORDS
  • Enter keywords & we'll notify you when a new patent matches your request (weekly update).

  • ORGANIZER
  • Save & organize patents so you can view them later.

  • RSS rss
  • Create custom RSS feeds. Track keywords without receiving email.

  • ARCHIVE
  • View the last few months of your Keyword emails.

  • COMPANY DIRECTORY
  • Patents sorted by company.

AdPromo(14K)

Follow us on Twitter
twitter icon@FreshPatents

Wireless communication system and transmission device

last patentdownload pdfimage previewnext patent


Title: Wireless communication system and transmission device.
Abstract: The present invention relates to a wireless communication system to properly switch over a transmission method of radio signals corresponding to a configuration of a receiver. The wireless communication system according to the present invention includes a transmitting device having a plurality of antennas and capable of transmitting radio signals different from each other from these antennas, and a receiving device having at least one antenna and receiving the radio signals transmitted from the transmitting device. The receiving device comprises an information transmitting unit transmitting, to the transmitting device, configuration information about a configuration of the receiving device, and the transmitting device includes a transmitting unit transmitting the radio signals by a transmission method corresponding to the configuration information received from the receiving device. ...


USPTO Applicaton #: #20090325514 - Class: 455101 (USPTO) - 12/31/09 - Class 455 
Telecommunications > Transmitter >Diversity

view organizer monitor keywords


The Patent Description & Claims data below is from USPTO Patent Application 20090325514, Wireless communication system and transmission device.

last patentpdficondownload pdfimage previewnext patent

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No. 11/128,285, filed on May 13, 2005, now pending, the entire disclosures of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Present Invention

The invention relates to a wireless communication system including a transmitting device having a plurality of antennas and capable of transmitting different radio signals from the respective antennas, and to the transmitting device.

2. Description of the Related Art

MIMO (Multi Input and Multi Output) communication system is given as a communication system capable of improving a transmission rate (transmission capacity) as a total by transmitting different pieces of data by use of same frequency band (and further the same spread code) from a plurality of antennas in parallel. The MIMO communication system is that plural pieces of data are transmitted from a plurality of transmitting antennas in parallel, and the signals synthesized while passing through a variety of communication paths are received by a plurality of receiving antennas. FIG. 7 is a diagram showing an outline of the MIMO communication system. FIG. 7 shows, in the MIMO communication system configured by i-pieces of transmitting antennas 500 and j-pieces of receiving antennas 510, how plural pieces of data (x1-xi) are transmitted to the receiving antennas 510 from the transmitting antennas 500, and the respective antennas obtain signals y1-yj synthesized with these pieces of data (x1-xi).

Note that when the transmission signal from each antenna is designated by a transmission vector x, the receipt signal received by each antenna is designated by a receipt vector y, a state of a radio path is expressed as a channel matrix H, and a noise vector is designated by n, there is established a relationship such as y=Hx+n.

In the MIMO communications as shown in FIG. 7, a receiving-side device receiving the signals transmitted from the plurality of antennas and then synthesized, utilizes a method called MLD (Maximum Likelihood Detection) defined as a maximum likelihood decoding method in order to acquire an excellent radio characteristic. By this method, the receiving-side device detects a necessary piece of data by separating the synthesized signals. The MLD is a method of detecting a data pattern by judging, with respect to combinations of all the transmission data patterns that can be transmitted by the transmitting side, if transmitted in such a manner, how much a possibly-acquired receipt signal gets approximate to the actual receipt signal (a degree of maximum likelihood) (see FIG. 8). In the MLD, however, in the case of transmitting the signals from, for example, four pieces of transmitting antennas by 16 QAM (Quadrature Amplitude Modulation) defined as a digital modulation method of transmitting 4-bit data with one symbol, there is a necessity of obtaining the likelihood of data patterns numbered as tremendously as 65536 (=164). In this case, it follows that the receiving-side device detects the data pattern exhibiting the maximum likelihood from within this tremendous number of data patterns. Thus, the MIMO communication system requires an enormous throughput for the data detection.

A method for solving this problem involves employing Pre-Rake, etc. shown in FIG. 9(B) in the transmitting-side device. The method typified by Pre-Rake is a method for reducing the receiving-side processes by the signal processing on the transmitting side. For instance, FIG. 9 shows wireless communications based on normal CDMA (Code Division Multiple Access) (FIG. 9(A)) and CDMA-based wireless communications using Pre-Rake (FIG. 9(B)). In the normal CDMA-based wireless communications shown in FIG. 9(A), the receiving side detects the data by the signal processing (channel compensation) based on the transmission path information. On the other hand, in the case of employing Pre-Rake shown in FIG. 9(B), the signal processing is previously executed based on the transmission path information of the signal before transmitting the signals.

In the Pre-Rake method, for example, in the case of a transmission environment (an environment where a path 1 and a path 2 shown in FIG. 10(A) exit) as shown in FIG. 10(A), though normally the receiving side makes channel compensation corresponding to the transmission environment, the transmitting side executes a channel compensation process equivalent to that on the receiving side.

For instance, a weighting synthesis (Rake creating) unit as shown in FIG. 10(B) multiplies the transmission signal by a weighting coefficient of each transmission environment. With this operation, the receiving-side signal processing can be reduced.

A technology disclosed in the document (“Examinations about Configuration of Transmitter/Receiver of MTMT Array System Using Weight Batchwise Control at Base Station”, written by Hoshida, B-5-54, General Meeting of Electronic Information Communication Institution in 2002) is proposed as a method of increasing a channel capacity by executing this type of signal processing employing the transmission path information on the transmitting side in the MIMO communication system.

That is, in the MIMO communication system, there are proposed a method of using an MLD receiver requiring an enormous throughput for acquiring an excellent radio characteristic and a method of employing a simple receiver requiring merely a low throughput by executing the signal processing that previously takes account of the transmission path on the transmitting side.

A base station performing the MIMO communications, however, has a case of desiring to separately use the MLD receiver and the simple receiver. In this case, there is none of a method of making the above methods coexistent with each other.

SUMMARY

OF THE INVENTION

It is an object of the present invention to provide a wireless communication system capable of properly switching over a transmission method of a radio signal corresponding to a configuration of a receiver.

The present invention adopts the following configurations in order to solve the above-mentioned problems. Namely, the present invention is about a wireless communication system comprising a transmitting device having a plurality of antennas and capable of transmitting radio signals different from each other from the plurality of antennas, and a receiving device having at least one of antennas and receiving the radio signals transmitted from the transmitting device. In the present invention, the receiving device includes an information transmitting unit transmitting, to the transmitting device, configuration information about a configuration of the receiving device, and the transmitting device includes a transmitting unit transmitting the radio signals by a transmission method corresponding to the configuration information received from the receiving device.

In the present invention, the transmitting device is notified of the configuration information of the receiving device, and the transmitting device transmits the radio signals by a transmission method based on the notified configuration information.

Therefore, according to the present invention, the transmission method executed by the transmitting device can be changed corresponding to the configuration of the receiving device.

Further, in the present invention, the configuration information contains a piece of number-of-antenna information held by the receiving device, and the transmitting unit determines the transmission method on the basis of the number-of antenna information contained in the configuration information.

Hence, according to the present invention, the transmission method executed by the transmitting device can be changed corresponding to the number-of-antenna information of the receiving device.

Moreover, in the present invention, the receiving device further includes an extraction unit extracting, from the received radio signals, transmission characteristic information containing transmission path information corresponding to an environment where the radio signals are transmitted, the information transmitting unit transmits the configuration information and the transmission characteristic information, the transmitting device further includes a detection unit detecting the transmission path information from the transmission characteristic information received from the receiving device, and a transforming unit transforming the transmission signals on the basis of the detected transmission path information and the number-of-antenna information contained in the configuration information, and the transmitting unit transmits the radio signals corresponding to the transformed transmission signals.

In the present invention, the receiving device notifies the transmitting device of the transmission characteristic information and the configuration information of the receiving device. Then, the transmitting device detects the transmission path information from the notified transmission characteristic information. Further, the transmitting device transforms the transmission signals based on the detected transmission path information and the number-of-antenna information of the receiving device so that the receiving device can receive only the radio signals corresponding to the number-of-antenna information, and transmits the transformed signals.

Therefore, according to the present invention, it is possible to determine the transmission method corresponding to the number-of-antenna information of the receiving device having none of a high-level demodulating function by taking account of both of the number-of-antenna information of the receiving device and the transmission path information.

Note the present invention may be a program for actualizing any one of the functions described above. Moreover, the present invention may also be a readable-by-computer storage medium stored with such a program.



Download full PDF for full patent description/claims.

Advertise on FreshPatents.com - Rates & Info


You can also Monitor Keywords and Search for tracking patents relating to this Wireless communication system and transmission device patent application.
###
monitor keywords



Keyword Monitor How KEYWORD MONITOR works... a FREE service from FreshPatents
1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored.
3. Each week you receive an email with patent applications related to your keywords.  
Start now! - Receive info on patent apps like Wireless communication system and transmission device or other areas of interest.
###


Previous Patent Application:
Wireless communication apparatus and wireless communication method
Next Patent Application:
Beamforming and/or mimo rf front-end
Industry Class:
Telecommunications
Thank you for viewing the Wireless communication system and transmission device patent info.
- - - Apple patents, Boeing patents, Google patents, IBM patents, Jabil patents, Coca Cola patents, Motorola patents

Results in 0.60855 seconds


Other interesting Freshpatents.com categories:
Tyco , Unilever , 3m -g2-0.2405
     SHARE
  
           

FreshNews promo


stats Patent Info
Application #
US 20090325514 A1
Publish Date
12/31/2009
Document #
12556092
File Date
09/09/2009
USPTO Class
455101
Other USPTO Classes
International Class
04B7/02
Drawings
14


Antenna
Radio
Receiver


Follow us on Twitter
twitter icon@FreshPatents