Determining base station fronthaul transmission control based on loopback signal

• US 10,455,496 B2
• Filed: 10/06/2016
• Issued: 10/22/2019
• Est. Priority Date: 10/21/2015
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Wich, Andreas, Wiegner, Dirk
• Primary Examiner(s): Sobutka, Philip
• Application Number:
  US15/769,501
• Publication Number:
  US 20180310244A1
• Time in Patent Office: 1,111 Days
• Field of Search: 455522, 455524
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0212 of impulse response
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 25/0242 using matrix methods
• CPC Class Codes: H04L 25/0258 Channel estimation using zero-forcing criteria
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 52/14 Separate analysis of uplink or downlink
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 88/085 Access point devices with remote components
• CPC Class Codes: H04W 92/12 between access points and access point controllers
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

Embodiments relate to apparatuses (10; 20), methods and computer programs for determining transmission control information. The Apparatus (10) is suitable for a base band unit (110) of a base station transceiver (100) of a mobile communication system (300), the base station transceiver (100) further comprising one or more radio units (120) configured to wirelessly communicate with the base band unit (110) using one or more wireless fronthaul links. The apparatus (10) comprises at least one output (12) configured to transmit a downlink component of the one or more wireless fronthaul links to the one or more radio units (120). The apparatus (10) further comprises at least one input (14) configured to receive an uplink component of the one or more wireless fronthaul links from the one or more radio units (120). The apparatus (10) further comprises a control module (16) configured to control the at least one output (12) and the at least one input (14). The control module (16) is further configured to transmit a reference signal via the at least one output (12) to the one or more radio units (120). The control module (16) is further configured to receive a loopback version of the reference signal via the at least one input (14) from the one or more radio units (120). The control module (16) is further configured to determine transmission control information based on an attenuation of the reference signal determined based on the loopback version of the reference signal. The transmission control information comprises information related to a per-radio unit transmission power to be used by the one or more radio units (120) for transmissions on the one or more wireless fronthaul links. The control module (16) is further configured to provide the transmission control information to the one or more radio units (120) via the at least one output (12).

Claims

1. An apparatus for a base band unit of a base station transceiver of a mobile communication system, the base station transceiver further comprising one or more radio units configured to wirelessly communicate with the base band unit using one or more wireless fronthaul links, the apparatus comprising:

at least one output configured to transmit a downlink component of the one or more wireless fronthaul links to the one or more radio units;

at least one input configured to receive an uplink component of the one or more wireless fronthaul links from the one or more radio units; and

a control module configured to;

control the at least one output and the at least one input,

transmit a reference signal via the at least one output to the one or more radio units,

receive a loopback version of the reference signal via the at least one input from the one or more radio units,

determine information related to a per-radio unit transmission power to be used by the one or more radio units for transmissions on the one or more wireless fronthaul links using an attenuation of the reference signal determined based on the loopback version of the reference signal,

determine transmission control information comprising the information related to the per-radio unit transmission power, and

provide the transmission control information to the one or more radio units via the at least one output;

wherein the control module is configured to determine the per-radio unit transmission power based on an estimated interference and an estimated path loss, wherein the control module is configured to estimate the path loss based on the reference signal and the loopback version of the reference signal; and

wherein the control module is configured to determine the per-radio unit transmission power based on an optimization function, wherein the control module is configured to determine the per-radio unit transmission power such that a target Signal-to-Interference and Noise (SINR) for the uplink component is approximated based on

2. The apparatus of claim 1, wherein the loopback version of the reference signal corresponds to an analog conversion of the reference signal received at the one or more radio units,

and/or wherein the control module is configured to determine the transmission control information based on a path loss of the downlink component and based on a path loss of the uplink component in the loopback version of the reference signal.

3. The apparatus of claim 1, wherein the control module is further configured to determine information related to a transmission power to be used by the at least one output for transmissions on the one or more wireless fronthaul links based on the reference signal and the loopback version of the reference signal, and to adapt the transmitting of the downlink component of one or more wireless fronthaul signals at the at least one output based on the information related to a transmission power to be used on the at least one output.

4. The apparatus of claim 3, wherein the control module is configured to determine the transmission power to be used by the at least one output for transmissions on the one or more wireless fronthaul links based on an optimization function, wherein the control module is configured to determine the transmission power to be used by the at least one output such that a target Signal-to-Interference and Noise (SINR) for the downlink component is approximated based on

5. The apparatus of claim 1, wherein the control module is further configured to adapt the receiving of the uplink component of one or more wireless fronthaul signals at the at least one input based on the reference signal and the loopback version of the reference signal.

6. The apparatus of claim 1, wherein the control module is configured to determine an uplink channel estimation matrix and a downlink channel estimation matrix based on the reference signal and the loopback version of the reference signal to determine the transmission control information, or wherein the control module is configured to determine a joint uplink/downlink channel estimation matrix based on the reference signal and the loopback version of the reference signal to determine the transmission control information,

and/or wherein the control module is configured to determine information related to a quality of the received uplink component and wherein the control module is configured to adjust the transmission control information based on the information related to the quality of the received uplink component.

7. The apparatus of claim 1, wherein the transmission control information comprises information related to a power threshold for a transmission of the one or more wireless fronthaul links, and/or wherein the control module is further configured to determine the transmission control information based on a cell coverage plan of the one or more radio units.

8. The apparatus of claim 1, wherein the control module is configured to determine the transmission control information without using information related to a channel estimation of the one or more wireless fronthaul links carried out at the one or more radio units.

9. An apparatus for a radio unit of a base station transceiver of a mobile communication system, the base station transceiver further comprising a base band unit configured to wirelessly communicate with the radio unit using a wireless fronthaul link, the apparatus comprising:

at least one input configured to receive a downlink component of the wireless fronthaul link from the base band unit;

at least one output configured to transmit an uplink component of the wireless fronthaul links to the base band unit; and

a control module configured to;

control the at least one input and the at least one output,

receive a reference signal via the at least one input from the base band unit,

loopback a loopback version of the received reference signal via the at least one output to the base band unit,

receive transmission control information from the base band unit, wherein the transmission control information comprises information related to a per-radio unit transmission power to be used by the radio unit for transmissions on the wireless fronthaul link, and

adapt the transmission power of the uplink component via the at least one output based on the transmission control information;

wherein the per-radio unit transmission power is determined based on an estimated interference and an estimated path loss, wherein the estimated path loss is estimated based on the reference signal and the loopback version of the reference signal; and

wherein the per-radio unit transmission power is determined based on an optimization function, wherein the per-radio unit transmission power is determined such that a target Signal-to-Interference and Noise (SINR) for the uplink component is approximated based on

10. The apparatus of claim 9, wherein the control module is configured to determine the loopback version of the received reference signal by analogously converting the received reference signal,

and/or wherein the downlink component uses a downlink carrier frequency, wherein the uplink component uses an uplink carrier frequency, and wherein the control module is configured to determine the loopback version of the received reference signal by analogously converting the received reference signal from the downlink carrier frequency to the uplink carrier frequency.

11. A method for a base band unit of a base station transceiver of a mobile communication system, the base station transceiver further comprising one or more radio units configured to wirelessly communicate with the base band unit using one or more wireless fronthaul links, the method comprising:

transmitting a reference signal to the one or more radio units;

receiving a loopback version of the reference signal from the one or more radio units;

determining information related to a per-radio unit transmission power to be used by the one or more radio units for transmissions on the one or more wireless fronthaul links using an attenuation of the reference signal determined based on the loopback version of the reference signal;

determining transmission control information comprising the information related to the per-radio unit transmission power; and

providing the transmission control information to the one or more radio units;

determining information related to a transmission power to be used by at least one output for transmissions on the one or more wireless fronthaul finks based on the reference signal and the loopback version of the reference signal, and adapting the transmitting of a downlink component of one or more wireless fronthaul signals at the at least one output based on the information related to a transmission power to be used on the at least one output; and

wherein;

(i) the transmission power to be used by the at least one output for transmissions on the one or more wireless fronthaul links is determined based on an optimization function, wherein the transmission power to be used by the at least one output is determined such that a target Signal-to-Interference and Noise (SINR) for the downlink component is approximated based on

12. A computer program product comprising a non-transitory computer readable medium having computer readable program code embodied therein, the computer readable program code being configured to implement the method of claim 11, when being loaded on a computer, a processor, or a programmable hardware component.

13. Method A method for a radio unit of a base station transceiver of a mobile communication system, the base station transceiver further comprising a base band unit wirelessly communicating with the radio unit using a wireless fronthaul link, the method comprising:

receiving a reference signal from the base band unit;

looping back a loopback version of the received reference signal to the base band unit;

receiving transmission control information from the base band unit, wherein the transmission control information comprises information related to a per-radio unit transmission power to be used by the radio unit for transmissions on the wireless fronthaul link;

adapting the transmission power for transmissions on the wireless fronthaul link based on the transmission control information;

wherein the per-radio unit transmission power is determined based on an estimated interference and an estimated path loss, wherein the estimated path loss is estimated based on the reference signal and the loopback version of the reference signal; and

wherein the per-radio unit transmission power is determined based on an optimization function, wherein the per-radio unit transmission power is determined such that a target Signal-to-Interference and Noise (SINR) for the uplink component is approximated based on

14. A computer program product comprising a non-transitory computer readable medium having computer readable program code embodied therein, the computer readable program code being configured to implement the method of claim 13, when being loaded on a computer, a processor, or a programmable hardware component.