Uplink measurements for wireless systems
A method for measuring channel quality in a wireless transceiver is disclosed, comprising: receiving, at a wireless transceiver, an analog signal from a user equipment (UE); converting the analog signal to a plurality of digital samples at an analog to digital converter (ADC); performing a fast Fourier transform (FFT) on the plurality of digital samples to generate frequency domain samples; identifying an uplink demodulation reference signal (DMRS) symbol; performing channel estimation on the DMRS symbol to identify an estimate of channels; creating a noise covariance matrix from the estimate of channels; and deriving an interference measure from the noise covariance matrix.
1. A method for measuring channel quality in a wireless transceiver, comprising:
receiving, at a wireless transceiver, an analog signal from a user equipment (UE);
converting the analog signal to a plurality of digital samples at an analog to digital converter (ADC);
performing a fast Fourier transform (FFT) on the plurality of digital samples to generate frequency domain samples;
identifying an uplink demodulation reference signal (DMRS) symbol;
performing channel estimation on the DMRS symbol to identify an estimate of channels;
creating a noise covariance matrix from the estimate of channels;
deriving an interference measure from the noise covariance matrix;
wherein the interference measure comprises noise plus interference per resource block, derived as an average of summation of diagonal matrix elements over a plurality of slots and a plurality of antennas, and
wherein the diagonal matrix elements are noise plus interference components.
2. The method of claim 1 , wherein the wireless transceiver is an LTE or LTE-A eNodeB, and the analog signal is a physical uplink shared channel (PUSCH).
3. The method of claim 1 , wherein the interference measure further comprises one of:
interference per resource block; noise per resource block; thermal noise power; interference power; noise plus interference per resource block; or noise power per resource block.
4. The method of claim 1 , further comprising obtaining a second interference measure that is interference per resource block, derived according to an equation
IP
(
p
)
=
1
N
off
_
diag
*
N
slot
∑
o
=
1
Noff
_
diag
∑
t
=
1
Nslot
C
o
,
t
.
p
,
where
C o,t.p is a noise covariance matrix off-diagonal;
Noff_diag is a number of off-diagonal elements in a noise covariance matrix; and
Nslot is a number of slots over which an average is computed.
5. The method of claim 1 , wherein the interference measure is noise plus interference per resource block, derived according to an equation
NIP
(
p
)
=
1
N
diag
*
N
slot
∑
d
=
1
Ndiag
∑
t
=
1
Nslot
C
d
,
t
.
p
,
where
C d,t.p is a Noise Covariance Matrix diagonal;
Ndiag is a number of diagonal elements in the Noise Covariance Matrix; and
Nslot is a number of slots over which an average is performed.
6. The method of claim 1 , further comprising performing inter cell interference coordination with a second wireless transceiver using the interference measure.
7. The method of claim 1 , further comprising adjusting a handover threshold based on the interference measure.
8. The method of claim 1 , further comprising transmitting the interference measure to a coordination server in an operator core network and receiving a configuration instruction from the coordination server based on the interference measure.
9. The method of claim 1 , further comprising scheduling data transmissions based on the interference measure.
10. The method of claim 1 , further comprising sending the interference measure to a scheduler.
11. The method of claim 1 , further comprising setting a modulation control scheme (MCS) for the UE based on the interference measure.
12. The method of claim 1 , wherein the receiving at a wireless transceiver comprises receiving at a 2G, 3G, 4G, 5G or Wi-Fi radio transceiver.
13. The method of claim 1 , further comprising transmitting the interference measure from a self-organizing network (SON) controller to a coordination server in an operator core network.