Method and apparatus for coordinating FDX and TDD communications in a communication system

Patent metadata

Field	Value
Publication number	US-11206162-B2
Application number	US-201816643785-A
Country	US
Kind code	B2
Filing date	Sep 10, 2018
Priority date	Sep 18, 2017
Publication date	Dec 21, 2021
Grant date	Dec 21, 2021

Abstract

The method includes transmitting by a first remote communication unit an upstream symbol with a first structure onto a first communication line at a reference time point trf, wherein the reference time point trf is determined based on a time of reception of a downstream symbol with the first structure tFDX_DS_RX and a first propagation delay over the first communication line tPD1, as trf=tFDX_DS_RX−tPD1; transmitting by a second remote communication unit an upstream symbol with a second structure onto the second communication line at tTDD_US_TX=trf−tPD2 during a time interval assigned for upstream transmission on the second communication line, wherein tPD2 is a second propagation delay over the second communication line, so that the upstream symbol with the second structure transmitted by the second remote communication unit arrives at the access node at the reference time point trf.

First claim

The invention claimed is:

1. A method of coordinating communications in a communication system, the communication system comprising an access node, communicatively coupled to:
a first set of remote communication units being configured to operate in a full duplex, FDX, mode via respective ones of a first set of communication lines, and
a second set of remote communication units being configured to operate in a Time Division Duplex, TDD, mode via respective ones of a second set of communication lines;
wherein symbols transmitted on a first communication line connecting a first remote communication unit belonging to the first set of remote communication units to the access node have a first structure which comprises a first cyclic prefix portion, a data portion and a first cyclic suffix portion, and wherein a cyclic extension comprising the first cyclic prefix portion and the first cyclic suffix portion has a duration (t CE );
and symbols transmitted on a second communication line connecting a second remote communication unit belonging to the second set of remote communication units to the access node have a second structure which comprises a second cyclic prefix portion and a data portion, the second cyclic prefix portion having the duration, and the symbol with the first structure and the symbol with the second structure having same symbol duration T symb ;
the method comprising:
transmitting by the first remote communication unit an upstream symbol with the first structure onto the first communication line at a reference time point t rf , wherein the reference time point t rf is determined based on a time of reception of a downstream symbol with the first structure t FDX_DS_RX and a first propagation delay over the first communication line t PD1 , as t rf =t FDX_DS_RX −t PD1 ;
transmitting by the second remote communication unit an upstream symbol with the second structure onto the second communication line at t TDD_US_TX =t rf −t PD2 during a time interval assigned for upstream transmission on the second communication line, wherein t PD2 is a second propagation delay over the second communication line.

2. A method according to claim 1 , further comprising:
determining the first propagation delay t PD1 and the second propagation delay t PD2 ;
sending the first propagation delay t PD1 to the first remote communication unit.

3. A method according to claim 1 , a FDX frame comprising a first FDX sub-frame and a second FDX sub-frame, the first FDX sub-frame comprising a first number of symbols with the first structure, the second FDX sub-frame comprising a second number of symbols with the first structure; a TDD frame comprising a downstream sub-frame and an upstream sub-frame, the downstream sub-frame comprising the first number of symbols with the second structure, the upstream sub-frame comprising the second number of symbols with the second structure;
wherein the upstream sub-frame is transmitted before the second FDX sub-frame is transmitted by an amount of time equal to the second propagation delay t PD2 .

4. A method according to claim 3 , wherein, the first FDX sub-frame is a downstream priority sub-frame where precedence is given to downstream communications from the access node to the first set of remote communication units, and the second FDX sub-frame is an upstream priority sub-frame where precedence is given to upstream communications from the first set of remote communication units to the access node.

5. A method according to claim 1 , further comprising:
determining a time gap t g2_TDD applied at the access node separating an end of a downstream sub-frame transmitted onto the second communication line and a beginning of a subsequent upstream sub-frame received from the second communication line as a predetermined length;
determining a time gap t g1′_FDX applied at the first remote communication unit and the access node separating an end of a first FDX sub-frame received from the first communication line and a beginning of a second FDX sub-frame transmitted onto the first communication line as t g1′_FDX =t g2_TDD −t PD1 ;
determining a time gap t g1′_TDD applied at the second remote communication unit separating an end of a downstream sub-frame received from the second communication line and a beginning of a subsequent upstream sub-frame transmitted onto the second communication line as t g1′_TDD =t g2_TDD −2t PD2 ;
applying the time gap t g1′_FDX at the first remote communication unit and the access node, and applying the time gap t g1′_TDD at the second remote communication unit.

6. A method according to claim 5 , wherein the predetermined length is determined according to the symbol duration T symb and a time gap t g1_TDD applied at the access node separating an end of the upstream frame received from the second communication line and a beginning of a subsequent downstream sub-frame transmitted onto the second communication line as t g2_TDD =T symb −t g1_TDD .

7. A method according to claim 1 , wherein the first communication line and the second communication line are in a same binder.

8. A method according to claim 1 , wherein the duration is determined to accommodate a delay spread and a propagation delay of a communication line having a longest supported loop length.

9. A method according to claim 1 , further comprising:
controlling the access node to transmit a symbol with the first structure to at least one remote communication unit belonging to the first set of remote communication units at the reference time point t rf .

10. A communication system comprising an access node, communicatively coupled to:
a first set of remote communication units being configured to operate in a full duplex, FDX, mode via respective ones of a first set of communication lines, and
a second set of remote communication units being configured to operate in a Time Division Duplex, TDD, mode via respective ones of a second set of communication lines;
wherein symbols transmitted on a first communication line connecting a first remote communication unit belonging to the first set of remote communication units to the access node have a first structure and comprises a first cyclic prefix portion, a data portion and a first cyclic suffix portion, and wherein a cyclic extension comprising the first cyclic prefix portion and the first cyclic suffix portion has a duration;
and symbols transmitted on a second communication line connecting a second remote communication unit belonging to the second set of remote communication units to the access node have a second structure and comprises a second cyclic prefix portion and a data portion, the second cyclic prefix portion having the duration, and the symbol with the first structure and the symbol with the second structure having same symbol duration T symb ;
wherein communications in the communication system are coordinated according to a method of claim 1 .

11. A customer Premises Equipment, CPE, wherein communications of the CPE are coordinated according to a method of claim 1 .

12. An access node, wherein communications of the access node are coordinated according to a method of claim 1 .

13. A communication controller for coordinating communications in a communication system, the communication system comprising an access node, communicatively coupled to:
a first set of remote communication units being configured to operate in a full duplex, FDX, mode via respective ones of a first set of communication lines, and
a second set of remote communication units being configured to operate in a Time Division Duplex, TDD, mode via respective ones of a second set of communication lines;
wherein symbo

Assignees

• Nokia Technologies Oy

Inventors

• Maes Jochen
• Lefevre Yannick
• Coomans Werner

Classifications

• H04L25/085 Primary

  Arrangements for reducing interference in line transmission systems, e.g. by differential transmission · CPC title

• H04L5/1469

  using time-sharing · CPC title

• H04B7/2656

  for structure of frame, burst · CPC title

• H04B3/32

  Reducing cross-talk, e.g. by compensating · CPC title

• H04L27/2607

  Cyclic extensions · CPC title