Time aligning in a distributed antenna system downlink data originating from two different types of donor base stations
AssigneeOutdoor Wireless Networks LLC
InventorsVan Erick Hanson, Steven B. Stuart
Life of this patent
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Abstract
This invention relates to a DAS comprising a digital donor interface circuit, an RF donor interface circuit, a first DAS propagation path, a second DAS propagation path, and a radio unit and configured to obtain a first propagation time delay for the first DAS propagation path and a second propagation time delay for the second DAS propagation path, obtain at least one of a time delay of the RF donor interface circuit and the digital donor interface circuit, determine a first downlink time delay value, and transmit the first downlink time delay value to a delay adjustment circuit in a downlink path of the DAS.
Claims17
A distributed antenna system (DAS) serving a digital interface base station and a radio frequency (RF)-interface base station and configured to time align contemporaneous time division duplexing (TDD) radio frames from the digital interface base station and the RF-interface base station in a radio unit, the DAS comprising:
- a digital donor interface circuit configured to couple the digital interface base station to the DAS and to communicate digital data for radio frames between the digital interface base station and the DAS;
- an RF donor interface circuit configured to couple the RF-interface base station to the DAS and to communicate data in radio frames in analog radio frequency (RF) signals between the RF-interface base station and the RF donor interface circuit;
- a first DAS propagation path;
- a second DAS propagation path;
- and
- the radio unit communicatively coupled to the digital donor interface circuit through the first DAS propagation path and communicatively coupled to the RF donor interface circuit through the second DAS propagation path, wherein the radio unit is configured to be coupled to a set of coverage antennas;
- wherein the DAS is configured to:
- obtain a first propagation time delay for the first DAS propagation path and a second propagation time delay for the second DAS propagation path;
- obtain at least one of a time delay of the RF donor interface circuit and the digital donor interface circuit;
- determine a first downlink time delay value equal to (i) a largest propagation delay (a) from an antenna port of the radio unit through the digital donor interface circuit or (b) from the antenna port of the radio unit through the RF donor interface circuit, minus (i) a shortest propagation time delay (x) from the antenna port of the radio unit through the digital donor interface circuit or (y) from the antenna port of the radio unit through the RF donor interface circuit;
- and
- transmit the first downlink time delay value to a delay adjustment circuit in a downlink path of the DAS having the shortest propagation time delay (p) from the antenna port of the radio unit through the digital donor interface circuit or (q) from the antenna port of the radio unit through the RF donor interface circuit, wherein the delay adjustment circuit is configured to delay TDD downlink data in the downlink path by the first downlink time delay value.
A method for time aligning, in a distributed antenna system (DAS), contemporaneous time division duplexing (TDD) radio frames from a digital interface base station and a radio frequency (RF)-interface base station in the DAS, the method comprising:
- obtaining a first propagation time delay for a first DAS propagation path and a second propagation time delay for a second DAS propagation path;
- obtaining at least one of a time delay of an RF donor unit and a digital donor unit;
- determining a first downlink time delay value equal to (i) a largest propagation delay (a) from an antenna port of a radio unit through the digital donor unit or (b) from the antenna port of the radio unit through the RF donor unit, minus (i) a shortest propagation time delay (x) from the antenna port of the radio unit through the digital donor unit or (y) from the antenna port of the radio unit through the RF donor unit;
- and
- transmitting the first downlink time delay value to a delay adjustment circuit in a downlink path of the DAS having the shortest propagation time delay (p) between the antenna port of the radio unit and through the digital donor unit or (q) between the antenna port of the radio unit and through the RF donor unit, wherein the delay adjustment circuit is configured to delay TDD downlink data in the downlink path by the first downlink time delay value.
A non-transitory computer readable medium storing a program causing at least one processor to execute a process to time align, in a distributed antenna system (DAS), contemporaneous time division duplexing (TDD) radio frames from a digital interface base station and a radio frequency (RF)-interface base station in the DAS, the process comprising:
- obtaining a first propagation time delay for a first DAS propagation path and a second propagation time delay for a second DAS propagation path;
- obtaining at least one of a time delay of a RF donor unit and a digital donor unit;
- determining a first downlink time delay value equal to (i) a largest propagation delay (a) from an antenna port of a radio unit through the digital donor unit or (b) from the antenna port of the radio unit through the RF donor unit, minus (i) a shortest propagation time delay (x) from the antenna port of the radio unit through the digital donor unit or (y) from the antenna port of the radio unit through the RF donor unit;
- and
- causing transmission of the first downlink time delay value to a delay adjustment circuit in a downlink path of the DAS having the shortest propagation time delay (p) from the antenna port of the radio unit through the digital donor unit or (q) from the antenna port of the radio unit through the RF donor unit, wherein the delay adjustment circuit is configured to delay TDD downlink data in the downlink path by the first downlink time delay value.
Dependencies are inferred from the claim text.