Method and Apparatus For Communication Site Planning

• US 20110090981A1
• Filed: 06/12/2008
• Published: 04/21/2011
• Est. Priority Date: 06/12/2008
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Hagerman, Bo, Lindgren, Ulf
• Granted Patent: US 8,219,074 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04W 16/18 Network planning tools

Abstract

The present invention relates to a solution for determining wireless communication cell characteristics related to wireless MIMO transmission mode and dynamically selecting suitable communication transmission mode for certain parts of the wireless communication cell. The solution uses a flatness spectrum analysis of received impulse response from a plurality of measurement points in the cell using a plurality of antennas in a wireless network access gateway, e.g. a base station.

Claims

1. A method of selecting transmission mode in a wireless network cell, comprising the steps of:

receiving in an infrastructure node at least one wireless signal from a mobile node in the wireless cell;

the signal being received in a plurality of antennas;

analyzing in the infrastructure node the signal using an algorithm for determining a spectrum flatness property of the signal;

storing in the infrastructure node in a database the determined flatness property of the signal in relation to a geographical position in the wireless cell;

using the determined flatness property for selecting transmission mode in communication between the infrastructure node and to a node located at the geographical position.

2. The method according to claim 1, further comprising a step of receiving signals relating to a plurality of positions in the wireless cell.

3. The method according to claim 1, wherein the step of analyzing comprise using a flatness algorithm:

4. The method according to claim 1, further comprising a step of sorting measurements into different transmission mode categories using at least one pre determined threshold of flatness index in relation to geographical positions in the cell.

5. The method according to claim 1, wherein the step of selecting transmission mode comprises one of multiple input multiple output or beam former.

6. The method according to claim 1, further comprising steps of comparing the received signal with the database and determining a geographical position of the mobile node using the comparison.

7. The method according to claim 6, further comprising a step of using the determined geographical position in an e-911 service.

8. The method according to claim 1, further comprising a step of selecting a sub set of antenna elements from available antenna elements using the result of selected transmission mode.

9. The method according to claim 1, further comprising a step of sending a message to a mobile node from the infrastructure node forcing the mobile node to transmit a signal useable in determining the flatness of a location.

10. The method according to claim 9, wherein the mobile node is forced to respond with a Random Access Channel message, i.e. a RACH message.

11. A communication node (4) for controlling wireless communication in a communication network, the node comprising a transceiver portion (208), a processing unit (201), a memory unit (202), and a network communication interface (203), the transceiver portion is arranged to communicate with a plurality of antennas (1), characterized in that the processing unit (201) is arranged to receive at least one wireless signal via the transceiver portion from a mobile node, to analyze the received signal using a flatness algorithm, to characterize a geographical position in a communication cell of the mobile node according to a flatness index, and to use the determined flatness index when selecting transmission mode between the communication node and a mobile node located at the geographical position.

12. The node according to claim 11, wherein the processor is further arranged to receive signal from the mobile node relating to a plurality of geographical positions of the communication cell.