Distributed base station, communication system, and signal transmission method thereof

• US 20070093273A1
• Filed: 10/12/2006
• Published: 04/26/2007
• Est. Priority Date: 10/18/2005
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Cai, Liyu
• Granted Patent: US 8,248,993 B2
• Time in Patent Office: Days
• US Class Current: 455/562.1
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/068 using space frequency diversity space-frequency coding H04L1/0606

Abstract

The present invention discloses a distributed base station serving mobile stations, which comprises multiple antenna-RF processing units and a central processing unit remotely connected with said multiple antenna-RF processing units. Each of the antenna-RF processing units has an antenna array formed by multiple antennas. Said central processing unit comprises: an MIMO coding unit for MIMO coding of data of each of the mobile stations so that data of each of the mobile stations generates multi-path data symbols; a beam-forming unit for multiplying each path data symbol of the multi-path data symbols of each of the mobile stations by a weighted coefficient vector corresponding to this path data symbol, to obtain beam-forming data of each path data symbol of each of the mobile stations; and an overlapping unit for, with respect to each antenna in said antenna-RF processing units, overlapping beam-forming data of the respective mobile stations for this antenna and feeding the overlapped beam-forming data to this antenna for transmission. The present invention further discloses a communication system having the above distributed base station and the corresponding signal transmission method.

Claims

1. A distributed base station (20) serving mobile stations, which comprises multiple antenna-RF processing units (21, 22, 23) and a central processing unit (24) remotely connected with said multiple antenna-RF processing units, each of the antenna-RF processing units having an antenna array formed by multiple antennas, said central processing unit comprising:

an MIMO coding unit (241) for MIMO coding of data of each of the mobile stations so that data of each of the mobile stations generates multi-path data symbols;

a beam-forming unit (242) for multiplying each path data symbol of the multi-path data symbols of each of the mobile stations by a weighted coefficient vector corresponding to this path data symbol, to obtain beam-forming data of each path data symbol of each of the mobile stations; and

an overlapping unit (243) for, with respect to each antenna in said antenna-RF processing units, overlapping beam-forming data of the respective mobile stations for this antenna and feeding the overlapped beam-forming data to this antenna for transmission.

2. The distributed base station (20) according to claim 1, wherein the number of the multi-path data symbols generated by said MIMO coding unit (241) is the same as the number of beams received by each of the mobile stations during signal reception.

3. The distributed base station (20) according to claim 1, wherein beam-forming data of each path data symbol of said mobile station forms beams, which point to said mobile stations, on all antennas of the corresponding antenna-RF processing unit.

4. The distributed base station (20) according to claim 1, wherein a weighted coefficient vector of each of the mobile stations on each antenna of each of the antenna-RF processing unit is calculated using channel measurement and feedback information of the mobile stations and based on a criterion for reducing interference on other mobile stations.

5. The distributed base station (20) according to claim 1, wherein said MIMO coding unit (241) performs coding using Space Time Block Code, Space Frequency Block Code or Spatial Reuse.

6. A communication system (30) comprising a distributed base station (20) according to claim 1 and multiple mobile stations (MT1, MT2 and MT3), wherein beams which said distributed base station (20) directionally transmits to each of the mobile stations via its antennas constitute an MIMO transmission system together with antennas of the corresponding mobile station.

7. A method of signal transmission between a distributed base station and mobile stations, wherein said distributed base station (20) comprises multiple antenna-RF processing units (21, 22, 23) and a central processing unit (24) remotely connected with said multiple antenna-RF processing units, the method comprising the following steps:

an MIMO coding step for MIMO coding of data of said base station for each of the mobile stations to divide data of each of the mobile stations into multi-path data symbols;

a beam-forming data obtaining step for multiplying each path data symbol of the multi-path data symbols of each of the mobile stations by a weighted coefficient vector corresponding to this path data symbol to obtain beam-forming data of each path data symbol of each of the mobile stations; and

an overlapping step for, with respect to each antenna in said antenna-RF processing units, overlapping beam-forming data of the respective mobile stations for this antenna and feeding the overlapped beam-forming data to this antenna for transmission.

8. The method of signal transmission according to claim 7, wherein the number of the multi-path data symbols generated in said MIMO coding step is the same as the number of beams received by each of the mobile stations during signal reception.

9. The method of signal transmission according to claim 7, wherein beam-forming data of each path data symbol of said mobile station forms beams, which point to said mobile stations, on all antennas of the corresponding antenna-RF processing unit.

10. The method of signal transmission according to claim 7, wherein a weighted coefficient vector of each of the mobile stations on each antenna of each of the antenna-RF processing unit is calculated using channel measurement and feedback information of the mobile stations and based on a criterion for reducing interference on other mobile stations.

11. The method of signal transmission according to claim 7, wherein said MIMO coding step performs coding using Space Time Block Code, Space Frequency Block Code or Spatial Reuse.