US-12621033-B2 - Power saving mode coverage control

US12621033B2US 12621033 B2US12621033 B2US 12621033B2US-12621033-B2

Abstract

In order to reduce power consumption, an access node may turn off transmissions from one or more rows or columns of antennas in a mMIMO array. To help prevent the beam from overshooting (i.e., going beyond) an intended area of coverage when the access node turns off transmission by one or more rows, the access node also increases the electrical down tilt of the beam (i.e., angle of depression) to help contain the beam within its intended area of coverage. To help prevent problems with SSB beam selection and/or beam switching, when the access node turns off transmission by one or more columns, the access node reduces the number of SSB beams that are transmitted while sweeping SSBs over the sector thereby reducing the overlap of the (now) wider SSB beams.

Inventors

Sanghoon Sung

Assignees

T-MOBILE INNOVATIONS LLC

Dates

Publication Date: 20260505
Application Date: 20230906

Claims (20)

1 . A method of reducing interference, comprising: transmitting, by an access node using a massive multiple-input multiple-output antenna array comprising a first plurality of antennas and a second plurality of antennas, a first synchronization signal block, the first synchronization signal block being transmitted by the massive multiple-input multiple-output antenna array at a first beam angle of depression from horizontal; disabling the second plurality of antennas from transmitting a second synchronization signal block; and transmitting, by the access node using the first plurality of antennas and not using the second plurality of antennas, the second synchronization signal block at a second beam angle of depression from horizontal, the second beam angle of depression being greater than the first beam angle of depression.
2 . The method of claim 1 , wherein a difference between the first beam angle of depression and the second beam angle of depression is preconfigured.
3 . The method of claim 1 , further comprising: configuring a first wireless device with a first timing advance value.
4 . The method of claim 3 , further comprising: based on the first timing advance value meeting a threshold criteria, transmitting, by the access node using the first plurality of antennas and not using the second plurality of antennas, a third synchronization signal block at a third beam angle of depression from horizontal, the third beam angle of depression being greater than the second beam angle of depression.
5 . The method of claim 1 , wherein the first plurality of antennas are arranged horizontal rows.
6 . The method of claim 5 , wherein the second plurality of antennas are arranged in horizontal rows.
7 . The method of claim 1 , further comprising: enabling the second plurality of antennas to transmit a third synchronization signal block; and transmitting, by the access node using the first plurality of antennas and the second plurality of antennas, the third synchronization signal block at the first beam angle of depression from horizontal.
8 . A method of reducing interference, comprising: transmitting, by an access node using a massive multiple-input multiple-output antenna array comprising a first plurality of antennas and a second plurality of antennas, a first plurality of synchronization signal blocks in a first frame where there are a first integer number, greater than one, of synchronization signal blocks in the first plurality of synchronization signal blocks, the first plurality of synchronization signal blocks each being transmitted in the first frame by the massive multiple-input multiple-output antenna array at different azimuth angles; disabling the second plurality of antennas from transmitting a second plurality of synchronization signal blocks in a second frame; and transmitting, by the access node using the first plurality of antennas and not using the second plurality of antennas, a second plurality of synchronization signal blocks in a second frame where there are a second integer number, greater than one, of synchronization signal blocks in the second plurality of synchronization signal blocks, the second plurality of synchronization signal blocks each being transmitted in the second frame by the first plurality of antennas at different azimuth angles, the first integer number being greater than the second integer number.
9 . The method of claim 8 , wherein the first plurality of synchronization signal blocks are transmitted with narrower azimuth angles between adjacent ones of the first plurality of synchronization signal blocks than azimuth angles between adjacent ones of the second plurality of synchronization signal blocks.
10 . The method of claim 8 , wherein the first plurality of antennas are arranged vertical columns.
11 . The method of claim 10 , wherein the second plurality of antennas are arranged in vertical columns.
12 . The method of claim 11 , further comprising: enabling the second plurality of antennas to transmit a third plurality of synchronization signal blocks in a third frame.
13 . The method of claim 12 , further comprising: transmitting, by the access node using the first plurality of antennas and the second plurality of antennas, the third plurality of synchronization signal blocks in the third frame where there are the first integer number of synchronization signal blocks in the third plurality of synchronization signal blocks.
14 . The method of claim 13 , wherein the third plurality of synchronization signal blocks are each transmitted in the third frame at azimuth angles that correspond to the different azimuth angles that the first plurality of synchronization signal blocks were transmitted in the first frame.
15 . A method of operating a communication system, comprising: selecting, by an access node having a massive multiple-input multiple-output antenna array comprising a first plurality of antennas and a second plurality of antennas, the first plurality of antennas to transmit a first synchronization signal block; transmitting, by the access node using the first plurality of antennas and not the second plurality of antennas, the first synchronization signal block at a first beam angle of depression from horizontal; selecting, by the access node, the first plurality of antennas and the second plurality of antennas to transmit a second synchronization signal block; and transmitting, by the access node using the first plurality of antennas and the second plurality of antennas, the second synchronization signal block at a second beam angle of depression from horizontal, where the second beam angle of depression from horizontal is less than the first beam angle of depression from horizontal.
16 . The method of claim 15 , wherein a difference between the first beam angle of depression and the second beam angle of depression is preconfigured.
17 . The method of claim 15 , further comprising: configuring a first wireless device with a first timing advance value.
18 . The method of claim 17 , further comprising: based on the first timing advance value meeting a threshold criteria, transmitting, by the access node using the first plurality of antennas and not using the second plurality of antennas, a third synchronization signal block at a third beam angle of depression from horizontal, the third beam angle of depression being greater than the first beam angle of depression.
19 . The method of claim 18 , wherein the first plurality of antennas are arranged in a first at least one horizontal row.
20 . The method of claim 19 , wherein the second plurality of antennas are arranged in a second at least one horizontal row.

Description

TECHNICAL BACKGROUND As wireless networks evolve and grow, there are ongoing challenges in providing high-quality service to increasing numbers of wireless devices in various coverage areas of a wireless network. Wireless networks may be configured to utilize massive multiple-input multiple-output (mMIMO), in which multiple data streams can be directed towards a plurality of wireless devices that are selected to participate in a MIMO operating mode based on the orthogonality of transmission, thereby maximizing resources. MIMO has been identified as one of the promising air interface technologies to address the capacity requirement required demanded by 5G networks, and increasingly access nodes with multiple antenna arrays are being deployed in wireless networks. In order to save power consumption, mMIMO may dynamically activate and deactivate transmit antenna branches in order to save power. These antenna branches may be activated and/or deactivated when certain conditions are met. These conditions may include, for example, when the number of connected user equipment devices is below a threshold and/or during a defined period of time (e.g., between 1 a.m. and 4 a.m.). However, reducing the number of transmit antennas alters the radiation pattern of the mMIMO array such that a mMIMO array in power saving mode may interfere with other nearby cellular sites and/or sectors. Overview Examples described herein include systems, methods, wireless devices, access nodes, and non-transitory computer readable mediums for reducing interference in mMIMO networks. An exemplary method for reducing interference in mMIMO networks includes transmitting, by an access node using a massive multiple-input multiple-output antenna array comprising a first plurality of antennas and a second plurality of antennas, a first synchronization signal block, where the first synchronization signal block is transmitted by the massive multiple-input multiple-output antenna array at a first beam angle of depression from horizontal. The second plurality of antennas from transmitting a second synchronization signal block are then disabled. By the access node and using the first plurality of antennas and not using the second plurality of antennas, the second synchronization signal block is transmitted at a second beam angle of depression from horizontal, the second beam angle of depression being greater than the first beam angle of depression. An additional example includes another method of reducing interference in mMIMO networks. This method of reducing interference in mMIMO networks includes transmitting, by an access node using a massive multiple-input multiple-output antenna array comprising a first plurality of antennas and a second plurality of antennas, a first plurality of synchronization signal blocks in a first frame where there are a first integer number, greater than one, of synchronization signal blocks in the first plurality of synchronization signal blocks. The first plurality of synchronization signal blocks each being transmitted in the first frame by the massive multiple-input multiple-output antenna array at different azimuth angles. The second plurality of antennas fare disabled from transmitting a second plurality of synchronization signal blocks in a second frame. By the access node using the first plurality of antennas and not using the second plurality of antennas, a second plurality of synchronization signal blocks are transmitted in a second frame where there are a second integer number, greater than one, of synchronization signal blocks in the second plurality of synchronization signal blocks and the second plurality of synchronization signal blocks each is transmitted in the second frame by the first plurality of antennas at different azimuth angles, where the first integer number being greater than the second integer number. In yet a further example, a method of operating a communication system includes selecting, by an access node having a massive multiple-input multiple-output antenna array comprising a first plurality of antennas and a second plurality of antennas, the first plurality of antennas to transmit a first synchronization signal block. By the access node using the first plurality of antennas and not the second plurality of antennas, the first synchronization signal block is transmitted at a first beam angle of depression from horizontal. By the access node, the first plurality of antennas and the second plurality of antennas are selected to transmit a second synchronization signal block. By the access node using the first plurality of antennas and the second plurality of antennas, the second synchronization signal block is transmitted at a second beam angle of depression from horizontal, where the second beam angle of depression from horizontal is less than the first beam angle of depression from horizontal. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts an exemplary system for wireless communication, i