Method for communication in a communication network

1 . A method for communication the method comprising:

signaling, by a base station (BS), at least one antenna port number from a plurality of antenna port numbers to the at least one user equipment (UE), for reference signal (RS) transmission, wherein the at least one antenna port number is assigned according to at least one of a cell identifier, a sector identifier, and a user identifier, such that antenna port assignments differ across at least two sectors or base stations;

receiving, by the BS, data and a RS corresponding to the at least one UE, the data and the RS are being received on one or more receive antennas of the BS, wherein:

the RS comprises of occupied RS subcarriers and null subcarriers,

the occupied RS subcarriers and null subcarriers being mutually exclusive within a physical resource block (PRB), and

a location of occupied RS subcarriers and null subcarrier positions are selected according to the signaled at least one antenna port;

estimating, by the BS, one or more channel parameters, comprising channel state information (CSI), using the occupied subcarriers associated with the received RS;

estimating interference plus noise parameters, comprising interference plus noise covariance, using the null subcarriers, wherein said channel parameters and said interference plus noise parameters are associated with one or more receive antennas of the BS; and

equalizing, by the BS, the received data on the one or more receive antennas using the measured channel parameters and the interference plus noise parameters corresponding to the at least one signaled port to suppress inter-cell interference caused by UEs assigned the same antenna port in other sectors, for interference rejection and data detection.

2 . The method as claimed in claim 1 , wherein the RS is a demodulation reference signal (DMRS) configured according to a Fifth Generation New Radio (5G NR) DMRS configuration type-1 or configuration type-2.

3 . The method as claimed in claim 1 , wherein a location of occupied RS subcarriers and null subcarrier positions are associated with one of one OFDM symbol and one or more OFDM symbols within a same physical resource block (PRB).

4 . The method as claimed in claim 1 , wherein each of the plurality of BS signals at least one antenna port from a plurality of antenna port numbers to a connected UE, such that UEs scheduled in adjacent sectors or neighboring cells are assigned different antenna port numbers, and wherein the port number signaled by at least two BS are distinct.

5 . The method as claimed in claim 1 , wherein the channel parameters are channel state information (CSI) associated with the at least one connected UE and are estimated per receive antenna using only the occupied RS subcarriers.

6 . The method as claimed in claim 1 , wherein the method comprises estimating an interference plus noise covariance matrix per receive antenna using the interference plus noise parameters.

7 . The method as claimed in claims 5 , wherein the equalizing includes one or more equalization coefficients that are determined using at least one of the CSI and the interference plus noise covariance, the equalization coefficients being applied according to at least one of minimum mean square error (MMSE), interference rejection combining (IRC), or MMSE-IRC techniques.

8 . A base station, the base station comprising:

a transmitter configured to signal at least one user equipment (UE) with at least one antenna port number from a plurality of antenna port numbers for demodulation reference signal (DMRS) transmission, wherein the at least one antenna port number is assigned according to at least one of a cell identifier and a user identifier;

a receiver configured to receive data and a DMRS corresponding to the at least one UE, the DMRS comprising a plurality of occupied DMRS subcarriers and a plurality of null subcarriers, wherein a location of an occupied DMRS subcarriers and a position of a null subcarrier is determined according to the signaled at least one antenna port;

an estimator configured to estimate channel state information (CSI) according to the plurality of occupied DMRS subcarriers and to estimate interference plus noise covariance according to the null subcarriers; and

an equalizer configured to mitigate inter-cell interference by equalizing the received data according to the estimated CSI and the estimated interference plus noise covariance.

9 . The base station of claim 8 , wherein the transmitter is configured to assign alternative antenna port numbers to one or more UEs in different sectors to reduce inter-cell interference.

10 . The base station of claim 8 , wherein the transmitter is configured to assign a first antenna port number to a first sector, a second antenna port number to a second sector, and the first antenna port number to a third sector to limit interference to users having the same port number.

11 . The base station of claim 8 , wherein the estimator is configured to measure interference covariance only on a port assigned to a UE in a particular sector.

12 . The base station of claim 8 , wherein the equalizer is configured to determine equalization coefficients according to at least one of the estimated CSI and the estimated interference plus noise covariance.

13 . The base station of claim 8 , wherein:

the receiver is configured to receive the DMRS on one or more receive antennas, and

the estimator is configured to estimate interference plus noise covariance separately for even and odd subcarriers.

14 . The base station of claim 8 , wherein the transmitter is configured to signal antenna port numbers such that UEs in different sectors are alternatively assigned to different ports in a single-layer single-user multiple-input multiple-output (SU-MIMO) transmission scenario.

15 . The base station of claim 8 , wherein the processor is configured to determine the null subcarrier positions according to the DMRS configuration type-1, such that UEs transmitting on even subcarriers do not transmit on odd subcarriers and vice versa.

16 . The base station of claim 8 , wherein:

the receiver is configured to receive DMRS transmissions from UEs assigned with at least two different antenna port numbers in a two-layer SU-MIMO transmission, and

the estimator is configured to estimate inter-cell interference according to the assigned ports.

17 . The base station of claim 8 , wherein the equalizer is configured to perform interference rejection by leveraging interference plus noise covariance estimates obtained over multiple resource elements within a physical resource block (PRB).