Granted Patent B2

US 12,525,997 · App. 17/526,246 · Granted Jan 13, 2026

Inventors: Benny Vejlgaard (Gistrup, DK); Oana-Elena Barbu (Aalborg, DK); Johannes Harrebek (Aalborg, DK)

Assignee: NOKIA TECHNOLOGIES OY

H04B1/0017

Abstract

Claims (34)

1 . An apparatus comprising:

at least one processor; and

at least one memory including computer program code which, when executed by the at least one processor, cause the apparatus to perform:

generating a filtered transmit signal from an unfiltered transmit signal using a filtering function for compensating for in-band group delay ripple of a transmit forward path of a transmitter of a mobile communication system and residual absolute delay of the transmit forward path;

providing the filtered transmit signal for transmission using the transmit forward path of the transmitter;

receiving a receive signal using a wideband transmit feedback path of the transmitter of the mobile communication system;

generating an estimate of a transfer function of the transmit forward path; and

calculating an update of a filter function for compensating for in-band group delay ripple of the transmit forward path and residual absolute delay of the transmit forward path, wherein said filtering function includes a previous iteration of the filter function for compensating for said estimated transfer function of the transmit forward path.

2 . An apparatus as claimed in claim 1 , wherein the updated filter function is stored for use during subsequent transmissions.

3 . An apparatus as claimed in claim 1 , wherein the receive signal is tapped at an antenna of the transmitter.

4 . An apparatus as claimed in claim 1 , wherein generating the estimate of said transfer function comprises generating said estimate based on the unfiltered transmit signal, the filtered transmit signal, the receive signal and a transfer function of the wideband transmit feedback path.

5 . An apparatus as claimed in claim 1 , wherein said filtering function and said updated filter function include time shifts.

6 . An apparatus as claimed in claim 1 , wherein the computer program code, when executed by the at least one processor, further causes the apparatus to perform:

determining whether one or more of one or more trigger variables are above a relevant trigger threshold; and

updating said filter function accordingly.

7 . An apparatus as claimed in claim 1 , wherein the computer program code, when executed by the at least one processor, further causes the apparatus to perform: generating a parameterisation of the filter function.

8 . An apparatus comprising:

a timing shift module and a filter module for generating a filtered transmit signal from an unfiltered transmit signal using a filtering function for compensating for in-band group delay ripple of a transmit forward path of a transmitter of a mobile communication system and residual absolute delay of the transmit forward path;

a group delay compensation module for providing the filtered transmit signal for transmission using the transmit forward path of the transmitter;

a wideband transmit feedback path of a mobile communication system for receiving a receive signal using a wideband transmit feedback path of the transmitter of the mobile communication system;

a calculation module for generating an estimate of a transfer function of the transmit forward path; and

a coefficients update module for calculating an update of a filter function for compensating for in-band group delay ripple of the transmit forward path and residual absolute delay of the transmit forward path, wherein said filtering function includes a previous iteration of the filter function for compensating for said estimated transfer function of the transmit forward path.

9 . A method comprising:

generating a filtered transmit signal from an unfiltered transmit signal using a filtering function for compensating for in-band group delay ripple of a transmit forward path of a transmitter of a mobile communication system and residual absolute delay of the transmit forward path;

providing the filtered transmit signal for transmission using the transmit forward path of the transmitter;

receiving a receive signal using a wideband transmit feedback path of the transmitter of the mobile communication system;

generating an estimate of a transfer function of the transmit forward path; and

calculating an update of a filter function for compensating for in-band group delay ripple of the transmit forward path and residual absolute delay of the transmit forward path, wherein said filtering function includes a previous iteration of the filter function for compensating for said estimated transfer function of the transmit forward path.

10 . A computer program, embodied on a non-transitory computer readable medium, the computer program when executed by a processor, causes the processor to perform at least the following:

generating a filtered transmit signal from an unfiltered transmit signal using a filtering function for compensating for in-band group delay ripple of a transmit forward path of a transmitter of a mobile communication system and residual absolute delay of the transmit forward path;

providing the filtered transmit signal for transmission using the transmit forward path of the transmitter;

receiving a receive signal using a wideband transmit feedback path of the transmitter of the mobile communication system;

generating an estimate of a transfer function of the transmit forward path; and

calculating an update of a filter function for compensating for in-band group delay ripple of the transmit forward path and residual absolute delay of the transmit forward path, wherein said filtering function includes a previous iteration of the filter function for compensating for said estimated transfer function of the transmit forward path.

Assignments (2)

Priority Claims (1)

Continuity (1)

References Cited (38)