Downlink direction remote radio unit selection decision method and apparatus

Patent metadata

Field	Value
Publication number	US-10064065-B2
Application number	US-201514732431-A
Country	US
Kind code	B2
Filing date	Jun 5, 2015
Priority date	Dec 6, 2012
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A method includes: an RRU selection decision cycle of a current RRU shared cell arriving; and determining, according to a current downlink measurement item of a user terminal and an uplink measurement item of each RRU, that at least one RRU among the RRUs transmits a downlink carrier signal; or, determining, according to the current downlink measurement item of the user terminal, the uplink measurement item of each RRU, and power specification of each RRU, that at least one RRU among the RRUs transmits a downlink carrier signal, where a downlink channel includes: a traffic channel and a stand-alone dedicated control channel.

First claim

What is claimed is:

1. A downlink direction remote radio unit (RRU) selection decision method comprising:
acquiring a signal indicating an arrival of an RRU selection decision cycle of a current RRU shared cell, the RRU shared cell comprising two or more RRUs;
determining that at least one RRU among the two or more RRUs transmits a downlink carrier signal,
i. according to a current downlink reception level or quality of a user terminal and an uplink reception level or quality of each RRU; or
ii. according to the current downlink reception level or quality of the user terminal, the uplink reception level or quality of each RRU, and power specification of each RRU,
wherein a downlink channel comprises a traffic channel and a stand-alone dedicated control channel; and
determining a current RRU transmission mode based on a number of the at least one RRU among the two or more RRUs that transmits the download carrier signal.

2. The method according to claim 1 , wherein determining that at least one RRU among the two or more RRUs transmits the downlink carrier signal according to the current downlink reception level or quality of the user terminal and the uplink reception level or quality of each RRU, further comprises:
performing judgment according to the current downlink reception level or quality and the uplink reception level of each RRU, so as to determine whether to switch from the current RRU transmission mode to that a corresponding RRU transmits the downlink carrier signal.

3. The method according to claim 2 , wherein performing judgment comprises:
when the current RRU transmission mode is that a single RRU transmits the downlink carrier signal:
if the current downlink reception level or quality reaches a first threshold value, keeping the current RRU transmission mode unchanged; or
if a difference between the current downlink reception level or quality and the first threshold value is less than 0, and an estimated downlink diversity gain incurred by that two adjacent RRUs of a user terminal simultaneously transmit the downlink carrier signal is greater than an absolute value of the difference, selecting the two adjacent RRUs to transmit the downlink carrier signal; or
if the difference between the current downlink reception level or quality and the first threshold value is less than 0, and the estimated downlink diversity gain incurred by that the two adjacent RRUs of the user terminal simultaneously transmit the downlink carrier signal is less than or equal to the absolute value of the difference, selecting multiple RRUs among the two or more RRUs to transmit the downlink carrier signal.

4. The method according to claim 3 , wherein the uplink reception levels of the RRUs are sorted in descending order, the first two RRUs are the two adjacent RRUs of the user terminal, the estimated downlink diversity gain incurred by that the two simultaneously transmit the downlink carrier signal corresponds to a spatial distance between the two, or corresponds to a difference between the uplink reception levels of the two.

5. The method according to claim 2 , wherein performing judgement comprises:
when the current RRU transmission mode is that two RRUs transmit the downlink carrier signal:
if the current downlink reception level or quality is greater than a second threshold value, selecting an RRU with the greatest uplink reception level among the two or more RRUs to transmit the downlink carrier signal; or
if the current downlink reception level or quality is less than a third threshold value, selecting multiple RRUs among the two or more RRUs to transmit the downlink carrier signal; or
if the current downlink reception level or quality is greater than the third threshold value but less than the second threshold value, keeping the current RRU transmission mode unchanged.

6. The method according to claim 2 , wherein performing judgement comprises:
when the current RRU transmission mode is that multiple RRUs transmit the downlink carrier signal:
if the current downlink reception level or quality is greater than a fourth threshold value, selecting an RRU with the greatest uplink reception level among the two or more RRUs to transmit the downlink carrier signal; otherwise, keeping the current RRU transmission mode unchanged.

7. The method according to claim 1 , wherein determining that at least one RRU among the two or more RRUs transmits a downlink carrier signal according to the current downlink reception level or quality of the user terminal, the uplink reception level or quality of each RRU, and power specification of each RRU, further comprises:
performing judgment according to the current downlink reception level or quality of the user terminal, the uplink reception level or quality of each RRU, and the power specification of each RRU, so as to determine whether to switch from the current RRU transmission mode to that a corresponding RRU transmits the downlink carrier signal.

8. The method according to claim 7 , wherein performing judgement comprises:
when the current RRU transmission mode is that a single RRU transmits the downlink carrier signal:
if a current downlink reception level or quality reaches a first threshold value, but an uplink reception level of the single RRU is not the greatest one among uplink reception levels of the RRUs, performing evaluation according to power specification and uplink path loss of an RRU with the greatest uplink reception level among the two or more RRUs and power specification and uplink path loss of the single RRU that currently transmits the downlink carrier signal, so as to determine whether to select the RRU with the greatest uplink reception level among the two or more RRUs to transmit the downlink carrier signal.

9. The method according to claim 7 , wherein performing judgement comprises:
when the current RRU transmission mode is that two RRUs transmit the downlink carrier signal:
when a current downlink reception level or quality is greater than a third threshold value but less than a second threshold value, sorting uplink reception levels of the two or more RRUs in descending order to determine the first two RRUs;
if at least one of the two RRUs that currently transmit the downlink carrier signal is not among the first two RRUs, performing evaluation according to power specification and uplink path loss of the RRU that is among the two RRUs that currently transmit the downlink carrier signal but is not among the first two RRUs ranked in order of the uplink reception level and power specification and uplink path loss of the RRU that is among the first two RRUs but does not currently transmit the downlink carrier signal, so as to determine whether to select the RRU, which is among the first two RRUs but does not currently transmit the downlink carrier signal, to replace the RRU, which is among the two RRUs that currently transmit the downlink carrier signal but is not among the first two RRUs ranked in order of the uplink reception level, to transmit the downlink carrier signal.

10. The method according to claim 1 , further comprising:
accessing, by the user terminal, the current RRU shared cell in the following manner:
e: keeping that each RRU transmits the downlink carrier signal; and
f: when an RRU selection decision cycle arrives, determining, according to the current downlink reception level or quality and the uplink reception level of each RRU, whether to switch from that each RRU transmits the downlink carrier signal to that a single RRU or two RRUs among the two or more RRUs transmit the downlink carrier signal.

11. The method according to claim 10 , wherein f comprises:
if the current downlink reception quality reaches a

Assignees

• Huawei Tech Co Ltd

Inventors

• Yan Haidong
• Chen Wei
• Guo Jiang
• Xue Huaijie
• Su Zhiwei
• Liu Jingquan

Classifications

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W88/085

  Access point devices with remote components · CPC title

• H04W16/14 Primary

  Spectrum sharing arrangements {between different networks} · CPC title

• H04W72/042

  Electricity · mapped topic

• H04W24/10

  Scheduling measurement reports {; Arrangements for measurement reports} · CPC title