IMPLEMENTING TRANSMIT RDN ARCHITECTURES IN UPLINK MIMO SYSTEMS

• US 20130329820A1
• Filed: 02/25/2013
• Published: 12/12/2013
• Est. Priority Date: 06/11/2012
• Status: Active Grant

• Current Assignee: Magnolia Broadband Incorporated
• Original Assignee: Magnolia Broadband Incorporated
• Inventors: Harel, Haim, Wang, Sherwin J., Abreu, Eduardo, Kludt, Kenneth, Chen, Phil F.
• Granted Patent: US 9,154,204 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0404 the mobile station comprising multiple antennas, e.g. to provide uplink diversity
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
• CPC Class Codes: H04B 7/088 using beam selection

Abstract

A system for implementing a transmit uplink channel in MIMO RDN architecture is provided herein. The system includes a multiple-input-multiple-output (MIMO) transmitting system that includes a MIMO baseband module having N branches; and a radio distribution network (RDN) connected to the MIMO receiving system. The RDN includes at least one beamformer, wherein each of the beamformers feeds K transmit antennas, so that a total number of transmit antennas in the system is M=N*K. At least some of the beamformers include passive splitters/combiners configured to split the signal coming from the transmitter into multiple signals which are weighted individually going to each transmit antenna. The baseband module is configured to repeatedly apply a “blind scanning” process to at least some of the transmit antennas, one at a time, so that performance of the tested transmit beam can be graded.

Claims

1. A system comprising:

a multiple-input-multiple-output (MIMO) transmitting system comprising a MIMO baseband module having N branches; and

a radio distribution network (RDN) connected to the MIMO receiving system,

wherein the RDN comprises at least one beamformer, wherein each beamformer feeds K transmit antennas, so that a total number of transmit antennas in the system is M=N*K, wherein each beamformer includes a passive splitter/combiner configured to split the signal coming from the transmitter into multiple transmit signals, said transmit signals being weighted individually for each transmit antenna,

wherein the baseband module is configured to determine the weights of the transmitting antennas for each beamformer based on quality indicators derived from error rate measured at a receiving side associated with the transmit signals.

2. The system according to claim 1, wherein the quality indicators comprise Modulation Coding Scheme (MCS).

3. The system according to claim 1, wherein at least one of the beamformers operates under an optimization process, in which antenna beam configurations of the beamformer are checked using a blind scanning process, in which the quality indicators are used to determine a desirable antenna configuration.

4. The system according to claim 1, wherein the MIMO baseband module is configured to use Mobility Monitoring Indicators (MMI) to determine a subset L of K antennas in at least one of the beamformers, for participating in beamforming, wherein the L antennas are selected using a grading mechanism.

5. The system according to claim 1, wherein the RDN is configured to apply an optimization process, using the quality indicators for at least some of the antenna configurations forming the beam, for at least some of the beamformers, sequentially.

6. The system according to claim 1, wherein at least one of the beamformers is configured to apply a blind scanning process for its tested antennas, in a sequential manner, and wherein the quality indicators are used to determine the desirable weights for the beamformer, wherein the beamformer is further configured to maintain the determined weights until a next optimization process for the beamformer.

7. The system according to claim 4, wherein the baseband module is configured to repeatedly apply a “

look through”

process to all of the transmit antennas one at a time, so that a single transmit antenna in a specified beamformer is operative at a time, wherein antennas at other beamformers are further operative with all their antennas.

8. The system according to claim 4, wherein the grading mechanism comprises:

(a) grading antennas using MCS;

(b) picking a best graded antenna as an anchor;

(c) pairing the anchor with each of the other antennas, one by one;

(d) registering MCS for two or more relative phases; and

(e) selecting the best paired antennas and the anchor, as the L antennas.

9. The system according to claim, 8, wherein the MIMO baseband module is further configured to apply a fine tuning process, to the selected L antennas.

10. A method comprising:

setting up a revisit timer;

gauging a preferred number of L transmit antennas out of K participating antennas per beamformer in a multiple inputs multiple outputs (MIMO) transmit system having N beamformers, via mobility monitoring indicators (MMIs);

selecting the L specific antennas that constitutes the best subset; and

tuning the beamformers one by one until the revisit time has expired.

11. The method according to claim 10, further comprising repeating the setting, the gauging, the selecting, and the tuning with a new revisit time, once the revisit time expires.