Diversity transmission

• US 20030032453A1
• Filed: 07/25/2002
• Published: 02/13/2003
• Est. Priority Date: 01/28/2000
• Status: Active Grant

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Ylitalo, Juha, Katz, Marcos
• Granted Patent: US 7,149,547 B2
• Time in Patent Office: Days
• US Class Current: 455/562.1
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H04B 7/0617 for beam forming

Abstract

The invention relates to a method and a system for implementing diversity in transmission utilizing orthogonal antenna beams formed using digital beam forming methods. In this method antenna beams (604, 606) are directed to be adjacent so as to set at least one of the estimated directions of arrival (614) of the received signal within the range between antenna amplification maximums (610, 612) of the antenna beams and signal is sent using said antenna beams. An advantage provided by the method and system of the invention is to improve the performance of the system in the downlink direction and also to reduce the imbalance between the uplink performance and the downlink performance. The method of the invention also allows to carry out power control specifically for each antenna beam.

Claims

1. A method for implementing transmission diversity in a radio system, the method comprising the steps of

determining directions of arrival for a received signal,

forming orthogonal antenna beams in a transmitter,

directing the antenna beams to be adjacent so as to set at least one of the estimated directions of arrival of the received signal within the range between antenna amplification maximums of the antenna beams and transmitting signal using said antenna beams.

2. A method as claimed in claim 1, wherein the power of each antenna beam is separately determined.

3. A method as claimed in claim 1, wherein the powers of the antenna beams are substantially equal.

4. A method as claimed in claim 1, wherein the breadth of each antenna beam is separately determined.

5. A method as claimed in claim 1, wherein the breadths of the antenna beams are substantially equal.

6. A method as claimed in claim 1, wherein the shape of each antenna beam is arranged to an angular response of the radio channel.

7. A method as claimed in claim 1, wherein the location of a direction of arrival distribution of the received signal in relation to the transmission antenna beams determines the breadth of the transmission antenna beams.

8. A method as claimed in claim 1, wherein the location of the direction of arrival distribution of the received signal in relation to the transmission antenna beams determines the transmission power.

9. A transceiver comprising

means for determining directions of arrival for a received signal, and

means for forming orthogonal antenna beams,

means for directing antenna beams to be adjacent so as to set at least one of the estimated directions of arrival of the received signal within the range between antenna amplification maximums and means for transmitting signal using said antenna beams.

10. A transceiver as claimed in claim 9, wherein the transceiver is arranged to determine the power of each antenna beam separately.

11. A transceiver as claimed in claim 9, wherein the transceiver is arranged to determine the powers of the antenna beams to be substantially equal.

12. A transceiver as claimed in claims 9 to 11, wherein the transceiver comprises means for determining the breadth of each antenna beam separately.

13. A transceiver as claimed in claims 9 to 11, wherein the transceiver comprises means for determining the breadths of the antenna beams to be substantially equal.

14. A transceiver as claimed in claim 9, wherein the transceiver comprises the means for arranging the shape of each antenna beam to the angular response of a radio channel.

15. A transceiver as claimed in claim 9, wherein the transceiver comprises the means for determining the breadth of the transmission antenna beams utilizing the location of the direction of arrival distribution of the received signal in relation to the transmission antenna beams.

16. A transceiver as claimed in claim 9, wherein the transceiver comprises the means for determining the transmission power utilizing the location of the direction of arrival distribution of the received signal in relation to the transmission antenna beams.