Implementing blind tuning in hybrid MIMO RF beamforming systems

1. A method comprising:

receiving multiple input multiple output (MIMO) radio frequency (RF) signals through M antennas coupled via N beamformers to a MIMO receiving system having N channels, wherein M>N;

measuring channel fading rate at a baseband level;

grading each one of K antennas of each one of the N beamformers based on their total data throughput coming from various data streams,

wherein the total data throughput is represented by a total data throughput indicator (TDTI) derivable via a lookup table based on a channel quality indicator (CQI) criterion and measured signal to noise plus interference ratio (SINR);

determining a number of antennas L to be combined out of the K antennas, based on the measured fading rate, wherein the subset of L antennas is based on the total data throughput grades of the K antennas; and

repeatedly applying a tuning process to L antennas at each of the N beamformers.

2. The method according to claim 1 , wherein the channel fading rate is represented by measuring a mobility monitoring indicator (MMI).

3. A method comprising:

receiving multiple input multiple output (MIMO) radio frequency (RF) signals through M antennas coupled via N beamformers to a MIMO receiving system having N channels, wherein M>N;

measuring channel fading rate at a baseband level:

grading each one of K antennas of each one of the N beamformers based on their total data throughput coming from various data streams, wherein the grading is carried out by a process comprising:

isolating a given antenna and registering the reported signal to noise plus interference ratio (SINR) of each layer,

converting each SINR to channel quality indicator (CQI) and then to Data Rate via a lookup table, and

summing them up to provide total data throughput indicator (TDTI) grading, while said process is carried out with K or less antennas at the other beamformers;

determining a number of antennas L to be combined out of the K antennas, based on the measured fading rate, wherein the subset of L antennas is based on the total data throughput grades of the K antennas; and

repeatedly applying a tuning process to L antennas at each of the N beamformers.

4. The method according to claim 3 , further comprising a step of updating the SINR conversion in the lookup table in a case a new CQI report arrives.

5. The method according to claim 3 , wherein the channel fading rate is represented by measuring a mobility monitoring indicator (MMI).

6. A method comprising:

receiving multiple input multiple output (MIMO) radio frequency (RF) signals through M antennas coupled via N beamformers to a MIMO receiving system having N channels, wherein M>N;

measuring channel fading rate at a baseband level;

determining a number of antennas L to be combined out of K antennas of each one of the N beamformers, based on the measured fading rate; and

repeatedly applying a tuning process to L antennas at each of the N beamformers,

wherein said tuning process includes at least one round of coarse tuning process,

wherein the coarse tuning process comprises:

selecting best graded antenna as an anchor;

combining the anchor with the second best graded antenna and measure Total Data Throughput Indicator (TDTI);

flipping the phase of the second best antenna by approximately 180°, and measuring the TDTI;

choosing the better TDTI as preferred coarse phase;

combining the next best graded antenna with the previously combined antennas and measure the TDTI;

flipping the phase of the next best graded antenna and measure TDTI, and selecting the better one; and

repeating the adding of antennas to the combiner per their grading until all L antennas are added.

7. The method according to claim 6 , wherein said tuning process includes a fine tuning process.

8. A system comprising:

M antennas;

N beamformers connected to the M antennas;

a multiple input multiple output (MIMO) receiving system having N channels, connected to the N beamformers, wherein M>N; and

an antenna subset selection and tuning module configured to:

measure channel fading rate at a baseband level;

grade each one of K antennas, based on their total data throughput coming from various data streams, wherein K is a number of antennas connected to each one of the beamformers and wherein the total data throughput is represented by a total data throughput indicator (TDTI) derivable via a lookup table based on a channel quality indicator (CQI) criterion and measured signal to noise plus interference ratio (SINR);

determine a number of antennas L≦K to be combined at each one of the N beamformers, based on the measured fading rate and the total data throughput grades of the K antennas; and

repeatedly apply a tuning process to L antennas at each of the N beamformers.

9. The system according to claim 8 , wherein the channel fading rate is represented by measuring a mobility monitoring indicator (MMI).

10. A system comprising:

M antennas;

N beamformers connected to the M antennas;

a multiple input multiple output (MIMO) receiving system having N channels, connected to the N beamformers, wherein M>N; and

an antenna subset selection and tuning module configured to:

measure channel fading rate at a baseband level;

grade each one of K antennas, based on their total data throughput coming from various data streams, wherein K is a number of antennas connected to each one of the beamformers and wherein the grading of each one of the K antennas is carried out by a process comprising:

isolating a given antenna and registering the reported signal to noise plus interference ratio (SINR) of each layer;

converting each SINR to CQI and then to Data Rate via a lookup table; and

summing them up to provide TDTI grading, while said process is carried out with K or less antennas at the other beamformers;

determine a number of antennas L<K to be combined at each one of the N beamformers, based on the measured fading rate and the total data throughput grades of the K antennas; and

repeatedly apply a tuning process to L antennas at each of the N beamformers.

11. The system according to claim 10 , wherein the antenna subset selection and tuning module is further configured to update the SINR conversion in the lookup table in a case a new CQI report arrives.

12. The system according to claim 10 , wherein the channel fading rate is represented by measuring a mobility monitoring indicator (MMI).

13. A system comprising:

M antennas;

N beamformers connected to the M antennas;

a multiple input multiple output (MIMO) receiving system having N channels, connected to the N beamformers, wherein M>N; and

an antenna subset selection and tuning module configured to:

measure channel fading rate at a baseband level;

determine a number of antennas L≦K to be combined at each one of the N beamformers, wherein K is a number of antennas connected to each one of the beamformers, based on the measured fading rate; and

repeatedly apply a tuning process to L antennas at each of the N beamformers, wherein said tuning process includes at least one round of coarse tuning process, wherein the coarse tuning process comprises:

selecting best graded antenna as an anchor;

combining the anchor with the second best graded antenna and measure total data throughput indicator (TDTI);

flipping the phase of the second best antenna approximately 180°, and measuring the TDTI;

choosing the better TDTI as preferred coarse phase;

combining the next best graded antenna with the previously combined antennas and measure the TDTI;

flipping the phase of the next best graded antenna and measure TDTI, and select the better one; and

repeating the adding of antennas to the combiner per their grading till all L antennas are added.

14. The system according to claim 13 , wherein said tuning process includes a fine tuning process.