Granted Patent B2

US 12,671,617 · App. 18/551,299 · Granted Jun 30, 2026

Inventors: Jung-Fu Cheng (Fremont, CA); Mehrnaz Afshang (Fremont, CA); Stephen Grant (Pleasanton, CA)

Assignee: Telefonaktiebolaget LM Ericsson (Publ)

H04L27/2613H04L5/0007H04L25/03821H04L27/2607

Abstract

Claims (34)

1 . A method in a transmitter of one of a network node and a wireless device (WD), the method comprising:

determining, for a receiver, a cyclic block phase tracking reference signal (PTRS) sequence by cyclically extending a base sequence;

performing, based at least in part on the PTRS sequence, an inter-carrier interference (ICI) compensation algorithm of a specified level of complexity; and

transmitting the PTRS.

2 . The method of claim 1 , wherein determining the PTRS includes determining a different PTRS for each of a plurality of clusters.

3 . The method of claim 2 , wherein the PTRS for each cluster is based at least in part on cyclically shifting the PTRS of a first cluster of the plurality of clusters.

4 . The method of claim 3 , wherein cyclically shifting the PTRS includes shifting by an amount that is based at least in part on at least one of a resource block index, an orthogonal frequency division multiplex (OFDM) symbol index, a WD identification and a cell identification.

5 . The method of claim 2 , wherein a PTRS for a cluster is determined based at least in part on an element-wise product in the frequency domain of a base sequence common to all of the plurality of clusters and a cluster-specific sequence.

6 . The method of claim 5 , wherein the cluster-specific sequence is based at least in part on a complex exponential of a phase step times an index.

7 . The method of claim 5 , wherein the cluster-specific sequence is based at least in part on a scrambling sequence.

8 . The method of claim 7 , wherein the scrambling sequence is selected to minimize a peak to average power ratio of the transmitted PTRS.

9 . The method of claim 1 , wherein cyclically extending the base sequence includes appending a cyclic prefix and a cyclic postfix to the base sequence.

10 . The method of claim 1 , wherein cyclically extending the base sequence includes appending a last L−1 symbols of the base sequence to a beginning of the base sequence, L being a filter length of the ICI compensation algorithm.

11 . A transmitter for one of a network node and a wireless device (WD), the transmitter comprising:

processing circuitry configured to:

determine, for a receiver, a cyclic block phase tracking reference signal, (PTRS) sequence by cyclically extending a base sequence; and

perform, based at least in part on the PTRS sequence, an inter-carrier interference (ICI) compensation algorithm of a specified level of complexity; and

a radio interface in communication with the processing circuitry and configured to transmit the PTRS.

12 . The transmitter of claim 11 , wherein determining the PTRS includes determining a different PTRS for each of a plurality of clusters.

13 . A method in a receiver of one of a network node and a wireless device, WD, the method comprising:

receiving a phase tracking reference signal (PTRS), having a PTRS sequence;

determining intercarrier interference (ICI) compensation filter coefficients based at least in part on a circulant matrix of known PTRS sequences, a PTRS sequence being formed by cyclically extending a base sequence; and

applying a filter having the determined ICI compensation filter coefficients to the received PTRS sequence.

14 . The method of claim 13 , wherein determining a set of ICI filter coefficients is further based in part on a channel equalization applied to the received PTRS.

15 . The method of claim 13 , wherein the received PTRS includes a plurality of PTRS sequences, each PTRS sequence corresponding to a different cluster.

16 . The method of claim 13 , wherein determining the ICI filter coefficients includes determining a vector of ICI filter coefficients that minimizes a residue sum of squares of terms involving the circulant matrix times an ICI filter coefficient vector minus an equalized received PTRS vector.

17 . The method of claim 16 , wherein determining the vector of ICI filter coefficients that minimizes the residue sum of squares includes multiplying the circulant matrix by a Hermitian transpose of the circulant matrix.

18 . The method of claim 13 , wherein determining the ICI filter coefficients includes multiplying an equalized received PTRS vector by an inverse of the circulant matrix.

19 . A receiver for one of a network node and a wireless device (WD), the receiver comprising:

a radio interface configured to receive a phase tracking reference signal (PTRS), and

processing circuitry in communication with the radio interface and configured to:

determine intercarrier interference (ICI) compensation filter coefficients based at least in part on a circulant matrix of known phase tracking reference signal (PTRS) sequences, a PTRS sequence being formed by cyclically extending a base sequence; and

apply a filter having the determined ICI compensation filter coefficients to a received PTRS sequence.

20 . The receiver of claim 19 , wherein determining a set of ICI filter coefficients is further based in part on a channel equalization applied to the received PTRS.

Assignments (1)

Continuity (2)

References Cited (22)