US-12625230-B2 - Signal processing for OFDM radar systems

Abstract

In implementations of signal processing for OFDM radar systems, an OFDM transceiver of an ISAC system is operated in full-duplex mode in a downlink communication phase. The ISAC system generates sensing symbols for an OFDM radar system by combining OFDM communication symbols and repetitions of the OFDM communication symbols as the sensing symbols. The OFDM transceiver attenuates subcarriers of received sensing symbols for processing by the OFDM radar system to increase a signal-to-noise ratio of the received sensing symbols.

Inventors

• Wilhelmus Johannes Van Houtum
• Vinicius Oliari Couto Dias

Assignees

• NXP B.V.

Dates

Publication Date

20260512

Application Date

20230915

Claims (18)

1. 1 . A method comprising: operating, by an integrated sensing and communication (ISAC) system, an orthogonal frequency division multiplication (OFDM) transceiver in full-duplex mode in a downlink communication phase; generating, by the ISAC system, sensing symbols for an OFDM radar system by combining communication symbols and repetitions of the communication symbols; and attenuating, by the OFDM transceiver in the full-duplex mode, subcarriers of received sensing symbols for processing by the OFDM radar system by setting a subset of the subcarriers to approximately zero to increase a signal-to-noise ratio of the received sensing symbols.
2. 2 . The method of claim 1 , wherein attenuating the subcarriers removes the subcarriers from the received sensing symbols.
3. 3 . The method of claim 1 , wherein the subcarriers are attenuated at one or both of a transmitter and a receiver of the OFDM transceiver.
4. 4 . The method of claim 1 , wherein the subcarriers are attenuated and complex conjugate multiplication (CCM) is applied.
5. 5 . The method of claim 4 , wherein the subcarriers are attenuated based on having amplitudes that are greater than a high amplitude threshold.
6. 6 . The method of claim 1 , wherein the subcarriers are attenuated and spectral division (SD) is applied.
7. 7 . The method of claim 6 , wherein the subcarriers are attenuated based on having amplitudes that are less than a low amplitude threshold.
8. 8 . The method of claim 1 , further comprising: processing the received sensing symbols based on minimum mean square error (MMSE) estimation.
9. 9 . An integrated sensing and communication (ISAC) system comprising: an orthogonal frequency division multiplication (OFDM) radar system configured to process sensing symbols comprising communication symbols and repetitions of the communication symbols; and an OFDM transceiver configured to: operate in full-duplex mode in a downlink communication phase; and attenuate subcarriers of received sensing symbols for processing by the OFDM radar system by setting a subset of the subcarriers to approximately zero to increase a signal-to-noise ratio of the received sensing symbols.
10. 10 . The ISAC system of claim 9 , wherein the subcarriers are attenuated at one or both of a transmitter and a receiver of the OFDM transceiver.
11. 11 . The ISAC system of claim 9 , wherein the subcarriers are attenuated using complex conjugate multiplication (CCM) based on having amplitudes that are greater than a high amplitude threshold.
12. 12 . The ISAC system of claim 9 , wherein the subcarriers are attenuated using spectral division (SD) based on having amplitudes that are less than a low amplitude threshold.
13. 13 . The ISAC system of claim 9 , wherein attenuating the subcarriers removes the subcarriers from the received sensing symbols.
14. 14 . The ISAC system of claim 9 , wherein the OFDM radar is configured to process the received sensing symbols based on minimum mean square error (MMSE) estimation.
15. 15 . A non-transitory computer-readable medium storing a set of executable instructions, the set of executable instructions to manipulate at least one processor to: operate an orthogonal frequency division multiplication (OFDM) transceiver of an integrated sensing and communication (ISAC) system in full-duplex mode in a downlink communication phase; generate sensing symbols for an OFDM radar system of the ISAC system by combining communication symbols and repetitions of the communication symbols; and attenuate subcarriers of received sensing symbols for processing by the OFDM radar system by setting a subset of the subcarriers to approximately zero to increase a signal-to-noise ratio of the received sensing symbols.
16. 16 . The non-transitory computer-readable medium of claim 15 , wherein the subcarriers are attenuated using complex conjugate multiplication (CCM) based on having amplitudes that are greater than a high amplitude threshold.
17. 17 . The non-transitory computer-readable medium of claim 15 , wherein the subcarriers are attenuated using spectral division (SD) based on having amplitudes that are less than a low amplitude threshold.
18. 18 . The non-transitory computer-readable medium of claim 15 , wherein the set of executable instructions are configured to further manipulate the at least one processor to: process the received sensing symbols based on minimum mean square error (MMSE) estimation.

Description

BACKGROUND Integrated sensing and communication (ISAC) systems leverage wireless communication systems and sensor systems to facilitate both communications and radar sensing such that information collected from the radar sensing systems can be efficiently communicated to other devices or systems via the communication systems. When performing ISAC, there is typically at least some trade-off between the sensing and communication applications. For example, utilization of sensing symbols for radar sensing is additional overhead for the communications systems. In another trade-off example, techniques for reducing this overhead for the communications systems can introduce a low target signal-to-noise ratio for target estimation in the sensing systems. SUMMARY OF EMBODIMENTS The present disclosure may be better understood in view of the following examples, considered individually or in various combinations. Example 1: A method comprising: operating, by an integrated sensing and communication (ISAC) system, an orthogonal frequency division multiplication (OFDM) transceiver in full-duplex mode in a downlink communication phase; generating, by the ISAC system, sensing symbols for an OFDM radar system by combining communication symbols and repetitions of the communication symbols as the sensing symbols. Example 2: The method of Example 1, further comprising: attenuating, by the OFDM transceiver in the full-duplex mode, subcarriers of received sensing symbols for processing by the OFDM radar system to increase a signal-to-noise ratio of the received sensing symbols. Example 3: The method of Example 1, wherein attenuating the subcarriers removes the subcarriers from the received sensing symbols. Example 4: The method of Example 1, wherein the subcarriers are attenuated at one or both of a transmitter and a receiver of the OFDM transceiver. Example 5: The method of Example 1, wherein the subcarriers are attenuated and complex conjugate multiplication (CCM) is used to obtain channel information. Example 6: The method of Example 5, wherein the subcarriers are attenuated based on having amplitudes that are greater than a high amplitude threshold. Example 7: The method of Example 1, wherein the subcarriers are attenuated and spectral division (SD) is used to obtain channel information. Example 8: The method of Example 7, wherein the subcarriers are attenuated based on having amplitudes that are less than a low amplitude threshold. Example 9: The method of Example 1, further comprising: processing the received sensing symbols based on minimum mean square error (MMSE) estimation. Example 10: An ISAC system comprising: an OFDM radar system configured to process sensing symbols generated by combining communication symbols and repetitions of the communication symbols as the sensing symbols; and an OFDM transceiver configured to: operate in full-duplex mode in a downlink communication phase. Example 11: The ISAC system of Example 10, wherein the OFDM transceiver is further configured to: attenuate subcarriers of received sensing symbols for processing by the OFDM radar system to increase a signal-to-noise ratio of the received sensing symbols. Example 12: The ISAC system of Example 10, wherein the subcarriers are attenuated at one or both of a transmitter and a receiver of the OFDM transceiver. Example 13: The ISAC system of Example 10, wherein the subcarriers are attenuated using CCM based on having amplitudes that are greater than a high amplitude threshold. Example 14: The ISAC system of Example 10, wherein the subcarriers are attenuated using SD based on having amplitudes that are less than a low amplitude threshold. Example 15: The ISAC system of Example 10, wherein attenuating the subcarriers removes the subcarriers from the received sensing symbols. Example 16: The ISAC system of claim 10, wherein the OFDM radar is configured to process the received sensing symbols based on MMSE estimation. Example 17: A non-transitory computer-readable medium storing a set of executable instructions, the set of executable instructions to manipulate at least one processor to: operate an OFDM transceiver of an ISAC system in full-duplex mode in a downlink communication phase; generate sensing symbols for an OFDM radar system of the ISAC system by combining communication symbols and repetitions of the communication symbols as the sensing symbols; and attenuate subcarriers of received sensing symbols for processing by the OFDM radar system to increase a signal-to-noise ratio of the received sensing symbols. Example 18: The non-transitory computer-readable medium of Example 17, wherein the subcarriers are attenuated using CCM based on having amplitudes that are greater than a high amplitude threshold. Example 19: The non-transitory computer-readable medium of Example 17, wherein the subcarriers are attenuated using SD based on having amplitudes that are less than a low amplitude threshold. Example 20: The non-transitory computer-readable medium