BACKGROUND

In LTE 4G systems, uplink measurements such as Interference per Resource Block (RB), Noise per RB, Thermal Noise power and Interference Power hold significant value for the performance of the overall uplink system behavior. These measurement values are calibrated and passed over to higher layers, which can assist with the scheduling of RB's and modulation rate etc. These values also assist the major decision takings such as for inter cell interference coordination (ICIC), handover etc.

In Long Term Evolution (LTE/LTE-A), physical uplink shared channel (PUSCH) is used to transmit the uplink data from UE (user equipment) along with control information. PUSCH uses DMRS to help the receiver to estimate channel and equalize the received data. The DMRS also has a major significance in terms of deriving various major measurements. The significance of the measurement values is to assist with the scheduling of the RB in order to enhance the user data decoding and the overall system performance.

SUMMARY

Systems and methods for uplink measurements in wireless systems are disclosed.

In one embodiment, a method for measuring channel quality in a Long Term Evolution (LTE) transceiver is disclosed, comprising: receiving, at a Long Term Evolution (LTE) 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.

The LTE wireless transceiver may be an LTE or LTE-A eNodeB, and the analog signal may be a physical uplink shared channel (PUSCH). The interference measure may be 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. The interference measure may be interference per resource block, derived according to the equation found herein. The interference measure may be noise plus interference per resource block, derived according to the equation found herein. The method may further comprise performing inter cell interference coordination with a second wireless transceiver using the interference measure. The method may further comprise adjusting a handover threshold based on the interference measure. The method may further comprise 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. The method may further comprise scheduling data transmissions based on the interference measure. The method may further comprise sending the interference measure to a scheduler. The method may further comprise setting a modulation control scheme (MCS) for the UE based on the interference measure.

In another embodiment, an uplink receiver for a wireless base station is disclosed, comprising: an analog to digital conversion module, for converting a received analog signal to a plurality of digital samples; a fast Fourier transform (FFT) module for performing FFT on the plurality of digital samples to generate frequency domain samples; an uplink demodulation reference signal (DMRS) identification module for identifying a DMRS symbol from the frequency domain samples; and an uplink signal strength measurement module, coupled to the uplink DMRS identification module, configured to perform channel estimation on the DMRS symbol to identify an estimate of channels, create a noise covariance matrix from the estimate of channels, and derive an interference measure from the noise covariance matrix.

The wireless base station may be an eNodeB, and the analog signal may be a physical uplink shared channel (PUSCH) received from a user equipment (UE). The interference measure may be 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. The interference measure may be interference per resource block, derived according to the equation found herein. The interference measure may be noise plus interference per resource block, derived according to the equation found herein. The uplink receiver may be further configured to perform inter cell interference coordination with a second wireless transceiver using the interference measure. The uplink receiver may be further configured to adjust a handover threshold based on the interference measure. The uplink receiver may be further configured to schedule data transmissions based on the interference measure. The uplink receiver may be further configured to send the interference measure to a scheduler. The uplink receiver may be further configured to set a modulation control scheme (MCS) for the UE based on the interference measure. The uplink receiver may further comprise a self-organizing network (SON) module in communication with a coordination server in an operator core network, the SON module configured to transmit the interference module to the coordination server.

