Method and system for data transmission with a macrodiversity reception

• US 6,504,837 B1
• Filed: 12/16/1999
• Issued: 01/07/2003
• Est. Priority Date: 12/16/1998
• Status: Active Grant

• Current Assignee: IP Edge LLC
• Original Assignee: Siemens AG
• Inventors: Menzel, Christian
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): Trinh, Sonny
• Application Number:
  US09/465,281
• Time in Patent Office: 1,118 Days
• Field of Search: 370/328, 370/331, 370/334, 370/329, 370/336, 370/337, 370/345, 370/347, 370/442, 370/351, 370/350, 455/130, 455/132, 455/133, 455/134, 455/135, 455/137, 455/524, 455/525
• US Class Current: 370/351
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04

Abstract

In a method for transmitting data via a radio interface between base stations and subscriber stations in a radio communications system, the time slots in a frame are allocated to different base stations such that the base stations transmit exclusively in the time slots in the downlink direction which are allocated to them, but also receive in those time slots in the uplink direction which are not allocated to them. It is thus possible to combine the received signals from at least two base stations with one another. Without any significant additional complexity, the existing base stations, which are on standby during some time slots, can be used to provide a macrodiversity reception. The transmission quality is improved by the plurality of propagation paths which are evaluated in the uplink direction. A radio communications system is also provided.

Claims

1. A method for transmitting data via a radio interface between base stations and subscriber stations in a radio communications system, the method which comprises:

using a time-division multiplex process for organizing a radio interface within a frequency band such that a plurality of time slots constitute a frame;

selectively using the time slots in one of an uplink direction and a downlink direction;

allocating respective time slots of the plurality of time slots in the frame to respective base stations;

transmitting, with the respective base stations, using exclusively the respective time slots allocated to the respective base stations for the downlink direction;

receiving, with the respective base stations, in the respective time slots allocated to the respective base stations for the uplink direction as well as in further ones of the time slots not allocated to the respective base stations for the uplink direction; and

combining received signals from at least two of the base stations for a macrodiversity reception.

2. The method according to claim 1, which comprises using respective monitoring procedures in the respective base stations for determining time slots in the uplink direction not allocated to the respective base stations.

3. The method according to claim 1, which comprises reporting, from a central unit to the respective base stations, the time slots not allocated to the respective base stations in the uplink direction.

4. The method according to claim 1, wherein the respective base stations report among each other the time slots in the uplink direction not allocated to the respective base stations.

5. The method according to claim 1, which comprises:

providing the respective base stations as base stations for different sector cells; and

installing the base stations for the different sector cells at one location.

6. The method according to claim 1, which comprises:

providing the respective base stations as base stations for different sector cells; and

installing the base stations for the different sector cells at different locations.

7. The method according to claim 1, which comprises:

using a frequency band having a broad band width for the transmitting step; and

distinguishing signals transmitted at the same time within the frequency band on the basis of a connection-specific spread code.

8. The method according to claim 1, wherein the combining step includes a maximum ratio combination.

9. The method according to claim 1, wherein the combining step includes a selective combination.

10. A radio communications system, comprising:

a first base station and a second base station, said first and second base stations having a radio interface for transmitting data in a downlink direction and for receiving data in an uplink direction;

a radio resource controller connected to said first and second base stations for allocating radio resources and organizing said radio interface within a frequency band in accordance with a time-division multiplex scheme such that a plurality of time slots constitute a frame, each of said time slots being exclusively used in one of the uplink direction and the downlink direction;

said first base station having a transmitter transmitting in a given one of the time slots allocated to said first base station for the downlink direction;

said first base station having a first receiver for receiving in a further one of the time slots allocated to said first base station for the uplink direction;

said second base station having a second receiver receiving in another one of the time slot allocated to said second base station for the uplink direction and receiving in additional ones of the time slots not allocated to said second base station for the uplink direction; and

a combination device connected to said first and second base stations and combining received signals from said first and second base stations for a macrodiversity reception.

11. A radio communications system according to claim 10, wherein said first receiver also receives in time slots not allocated to said first base station for the uplink direction.

12. A radio communications system according to claim 10, including a subscriber station receiving in the given one of the time slots allocated to said first base station for the downlink direction and transmitting in the further one of the time slots allocated to said first base station for the uplink direction.