US 11,071,079 B2
Synchronizing multiple-input/multiple-output signals in distributed antenna systems
Van E. Hanson, Forest, VA (US)
Assigned to Andrew Wireless Systems GmbH, Buchdorf (DE)
Appl. No. 15/575,757
Filed by Andrew Wireless Systems GmbH, Buchdorf (DE)
PCT Filed Dec. 15, 2015, PCT No. PCT/IB2015/059644
§ 371(c)(1), (2) Date Nov. 20, 2017,
PCT Pub. No. WO2016/185261, PCT Pub. Date Nov. 24, 2016.
Claims priority of provisional application 62/164,986, filed on May 21, 2015.
Prior Publication US 2018/0124729 A1, May 3, 2018
Int. Cl. H04W 56/00 (2009.01); H04W 88/08 (2009.01)
CPC H04W 56/0025 (2013.01) [H04W 56/004 (2013.01); H04W 56/0045 (2013.01); H04W 56/0065 (2013.01); H04W 88/085 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method comprising:
transmitting signals between a head-end unit and remote units of a telecommunication system;
determining that a first delay of a signal path between the head-end unit and a first remote unit of the remote units is greater than each delay of signal paths between the headend unit and other remote units;
determining if a difference of the first delay from delays in other signal paths is greater than a threshold;
configuring, based on the first delay when the difference between the first delay from the delays in the other signal paths is not greater than the threshold and based on another delay when the difference between the first delay from the delays in the other signal paths is greater than the threshold, the telecommunication system to delay transmission of additional signals such that the additional signals are simultaneously transmitted to another unit by either the head-end unit or the remote units;
wherein the signals comprise Ethernet-framed data representing a set of multiple-input/multiple-output signals;
further wherein determining the first delay is greater than the delay of signal paths between the head-end unit and other remote units includes:
setting a real-time clock for the head-end unit and the remote units;
for each remote unit of the remote units:
transmitting between the head-end unit and the remote unit a message comprising an instruction to transmit a responsive message at a first time,
identifying a second time at which the responsive message is received by the head-end unit or the remote unit,
determining a delay from a difference between the first time and the second time; and
identifying a greatest delay among the remote units.