Adaptive cell shaping in codebook based full dimension multiple input-multiple output communications

A network node for setting an electrical tilt of an antenna array toward a distribution of wireless devices, WDs, the network node comprising:

• processing circuitry configured to, for each of at least one sector of an area covered by the antenna array:
• determine a function of precoding matrix indicators, PMIs, received from a plurality of WDs in the sector;
• determine a current electrical tilt angle of the sector based on the function of PMIs;
• compare a difference between the current electrical tilt angle of the sector and a previously determined electrical tilt angle of the sector to a first threshold;
• and
• set the electrical tilt angle of the sector based on the comparison.

A computer storage device storing a computer program that, when executed by at least one processor in a network node, performs a method for setting an electrical tilt of an antenna array toward a distribution of wireless devices, WDs, the method comprising:

• for each of at least one sector of an area covered by the antenna array:
• determining a function of precoding matrix indicators, PMIs, received from a plurality of WDs in the sector;
• determining a current electrical tilt angle of the sector based on the function of PMIs:
• comparing a difference between the current electrical tilt angle of the sector and a previously determined electrical tilt angle of the antenna array to a first threshold;
• and
• setting the electrical tilt angle of the antenna array based on the comparison.

A method in a network node for adapting an electrical tilt of an antenna array toward a distribution of wireless devices, WDs, the method comprising:

• for each of M sectors, S1 to Sm of an area covered by the antenna array:
• starting (S164) a timer;
• collecting precoding matrix indicators, PMIs, Xm, from a plurality of WDs served by the sector;
• when the timer expires, calculating a function, ƒ(Xm) of the PMIs;
• determining a current electrical tilt angle of the sector based on the function ƒ(Xm);
• comparing a difference between the current electrical tilt angle and a previously determined electrical tilt angle of the antenna array to a threshold;
• and
• when the difference exceeds the threshold (S176), setting (S178) the electrical tilt angle of the antenna array to:
• max(min (−Δθmin), +Δθmin);
• where is the current electrical tilt angle of the sector, is a current electrical tilt angle of an immediately precedent sector, is a current electrical tilt angle of a next-subsequent sector and Δθmin is a minimum angular spread between adjacent sectors.

A network node for adapting an electrical tilt of an antenna array toward a distribution of wireless devices, WDs, the network node comprising:

• processing circuitry configured to, for each of M sectors, S1 to Sm of an area covered by the antenna array:
• start a timer;
• collect precoding matrix indicators, PMIs, Xm, from a plurality of WDs served by the sector;
• when the timer expires, calculate a function, ƒ(Xm) of the PMIs;
• determine a current electrical tilt angle of the sector based on the function ƒ(Xm);
• compare a difference between the current electrical tilt angle and a previously determined electrical tilt angle of the antenna array to a threshold;
• and
• when the difference exceeds the threshold, set the electrical tilt angle of the antenna array to:
• max(min (−Δθmin), +Δθmin);
• where is the current electrical tilt angle of the sector, is a current electrical tilt angle of an immediately precedent sector, is a current electrical tilt angle of a next-subsequent sector and Δθmin is a minimum angular spread between adjacent sectors.