Patent Description:
In wireless communication networks, it is known to utilize frequency division multiplexing to enable efficient sharing of a wireless medium. For example in the case of WLAN (Wireless Local Area Network) systems according to the IEEE <NUM> standards family, the IEEE <NUM>. 11ax technology introduces various enhancements to the Physical Layer (PHY) and Medium Access Control (MAC), including Orthogonal Frequency Division Multiple Access (OFDMA) based sharing of a carrier. Further, the IEEE <NUM>. 11ax technology supports preamble puncturing and Dual Carrier Modulation (DCM). Details of the IEEE <NUM> ax technology are for example specified in IEEE P802.11ax™/D6. <NUM> Draft Standard for Information technology- Telecommunications and information exchange between systems Local and metropolitan area networks-Specific requirements Part <NUM>: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment <NUM>: Enhancements for High Efficiency WLAN (November <NUM>), in the following denoted as "IEEE <NUM>. 11ax Draft".

In OFDMA the available bandwidth of the shared transmission medium is divided into different parts which are allocated to different users. In the IEEE <NUM>. 11ax technology these parts are referred to as "Resource Unit" (RU). Preamble puncturing refers to the possibility to mute one or more RUs if at the time of transmission it is determined that there are ongoing transmissions overlapping in the frequency domain with some RUs. These RUs are muted, and the remaining RUs may be transmitted. <FIG> schematically illustrates an example of preamble puncturing in the IEEE <NUM>. 11ax technology. In this example, it is assumed that there are four users, allocated to different RUs, denoted as RU<NUM> to RU<NUM>. Further, it is assumed that high interference levels are detected in RU<NUM> and RU<NUM>. This may result in that a transmitter mutes RU<NUM> and RU<NUM> and proceeds to transmit in RU<NUM> and RU<NUM>. Preamble puncturing may help to improve efficiency of using of the shared wireless medium. In preamble puncturing as specified in the IEEE <NUM>. 11x Draft, either all the subcarriers allocated to one user are transmitted or all subcarriers allocated to one user are muted. In this respect, it is also noted that In preamble puncturing as specified in the IEEE <NUM>. 11x Draft not only the preamble but also the data of the wireless transmission are muted. Accordingly, also the preamble puncturing could also more generically be considered as puncturing of RUs.

DCM is a modulation technique intended to enhance the robustness of wireless transmissions. With DCM the same user code bits are modulated onto a pairs of subcarriers in order to increase the received SNR (Signal-to-Noise Ratio) through gains in power and frequency diversity. The IEEE <NUM>. 11ax technology supports DCM in both Single User (SU) and Multiuser (MU) modes. In either case, a given user is allocated one RU comprising N subcarriers, and bit sequences are mapped to a pair of symbols (dk,dq(k)) where k is a subcarrier index in the range <NUM>≤k<N/<NUM> and q(k) is in the range N/<NUM>≤q(k)<N, see section <NUM>. <NUM> of the IEEE <NUM>. 11ax draft. <FIG> schematically illustrates a corresponding example assuming that DCM is applied for a user, using OFDM (Orthogonal Frequency Division Multiplexing) modulation in an RU, which is allocated to the user and denoted as RUM. In accordance with the IEEE <NUM>. 11ax draft, DCM involves that a symbol of user data is modulated onto subcarriers with index k and that the same symbol is modulated onto subcarriers with index q(k)=k+ N/<NUM>.

Further, an enhancement of the WLAN technology according to the IEEE <NUM> standards family, denoted as EHT (Extremely High Throughput), proposes to increase the channel bandwidth to <NUM>, as well as introduce support for multi-link operation. With multi-link operation, the total aggregated bandwidth using several channels could exceed <NUM>. Since the bandwidth allocated to a single user can be very large, and as a consequence the probability of a user experiencing interference increases. The interference can be either static or intermittent. In the static case the interference arises from external sources, such as radars or fixed microwave links, which may occupy a bandwidth portion for long time periods and have priority over WLANs. In these cases the interference may be avoided by the transmitter since it can refrain from transmitting any information in the interfered bandwidth portions. In the intermittent case, the interference arises from other WLANs, and the transmitter may detect the interference just prior to transmission. If this happens, it may not have time to reformat the transmission to avoid sending information in the interfered bandwidth portion. For example, if many stations in overlapping BSSs (BSS: basic service set) are sharing the medium, the probability of intermittent, high interference levels in some bandwidth parts is not negligible. In view of this situation, "Preamble Puncturing and RU Aggregation", Internet document IEEE <NUM>-<NUM>/1869r0 (URL:"https://mentor. org/<NUM>/dcn/<NUM>/<NUM>-<NUM>-<NUM>-<NUM>-00be-preamble-puncturing-and-ru-aggregation. pptx", November <NUM>) proposes to introduce the possibility to assign more than one RU to a single user. Further, "Multi-RU Support", Internet document IEEE <NUM>-<NUM>/1908r0 (URL: "https://mentor. org/<NUM>/dcn/<NUM>/<NUM>-<NUM>-<NUM>-<NUM>-00be-multi-ru-support. pptx", November <NUM>) proposes to allow preamble puncturing for only a subset of the RUs assigned to a single user. In particular, it is proposed to introduce a new transmitter block denoted as RU parser, which distributes encoded data bits of a user to multiple RUs. In case intermittent interference is detected, it is possible to puncture one or more RUs, and if the channel code is strong enough, it is still possible for the receiver to decode the data.

When preamble puncturing is applied to a SU transmission as proposed above, as much as <NUM>% of the code bits may be punctured. Since the lowest code rate specified for the IEEE <NUM> standards family is <NUM>/<NUM>, the EHT technology may require new codes with lower rate to support puncturing of SU transmissions, in case of intermittent interference. Further, DCM as specified in the IEEE <NUM>. 11ax Draft is not designed for multi-RU transmissions.

<CIT> describes puncturing applied to coded data to puncture certain bits from the coded data. <CIT> describes puncturing of RUs.

Accordingly, there is a need for techniques which allow for redundantly utilizing multiple subcarriers when performing OFDM based wireless transmissions that may be subject to puncturing in the presence of intermittent interference.

According to an embodiment, a method of controlling wireless transmissions in a wireless communication system is provided. According to the method, a wireless transmitter transmits user data using OFDM modulation on a shared wireless medium having a bandwidth organized in multiple RUs. Based on a mapping of the user data to the RUs, the wireless transmitter modulates a symbol of the user data onto a first set of subcarriers of a first RU of the RUs and redundantly modulates the symbol onto a second set of subcarriers of a second RU of the RUs. The mapping of the user data to the RUs is based on possible puncturing patterns applied to the RUs to mute one or more of the resource units in response to detecting intermittent interference.

According to a further embodiment, a method of controlling wireless transmissions in a wireless communication system is provided. According to the method, a wireless receiver receives user data using OFDM modulation on a shared wireless medium having a bandwidth organized in multiple RUs. Based on a mapping of the user data to the RUs, the wireless receiver demodulates a symbol of the user data from a first set of subcarriers of a first RU of the RUs and redundantly demodulates the symbol from a second set of subcarriers of a second RU of the RUs. The mapping of the user data to the RUs is based on possible puncturing patterns applied to the RUs to mute one or more of the resource units in response to detecting intermittent interference.

According to a further embodiment, a wireless transmitter for a wireless communication system is provided. The wireless transmitter is configured to transmit user data using OFDM modulation on a shared wireless medium having a bandwidth organized in multiple RUs. Further, the wireless transmitter is configured to, based on a mapping of the user data to the RUs, modulate a symbol of the user data onto a first set of subcarriers of a first resource unit of the RUs and redundantly modulate the symbol onto a second set of subcarriers of a second RU of the RUs. The mapping of the user data to the RUs is based on possible puncturing patterns applied to the RUs to mute one or more of the resource units in response to detecting intermittent interference.

According to a further embodiment, a wireless transmitter for a wireless communication system is provided. The wireless transmitter comprises at least one processor and a memory. The memory contains instructions executable by said at least one processor, whereby the wireless transmitter is operative to transmit user data using OFDM modulation on a shared wireless medium having a bandwidth organized in multiple RUs. Further, the memory contains instructions executable by said at least one processor, whereby the wireless transmitter is operative to, based on a mapping of the user data to the RUs, modulate a symbol of the user data onto a first set of subcarriers of a first resource unit of the RUs and redundantly modulate the symbol onto a second set of subcarriers of a second RU of the RUs. The mapping of the user data to the RUs is based on possible puncturing patterns applied to the RUs to mute one or more of the resource units in response to detecting intermittent interference.

According to a further embodiment, a wireless receiver for a wireless communication system is provided. The wireless receiver is configured to receive user data using OFDM modulation on a shared wireless medium having a bandwidth organized in multiple RUs. Further, the wireless receiver is configured to, based on a mapping of the user data to the RUs, demodulate a symbol of the user data from a first set of subcarriers of a first RU of the RUs and redundantly demodulate the symbol from a second set of subcarriers of a second RU of the RUs. The mapping of the user data to the RUs is based on possible puncturing patterns applied to the resource RUs to mute one or more of the resource units in response to detecting intermittent interference.

According to a further embodiment, a wireless transmitter for a wireless communication system is provided. The wireless transmitter comprises at least one processor and a memory. The memory contains instructions executable by said at least one processor, whereby the wireless transmitter is operative to receive user data using OFDM modulation on a shared wireless medium having a bandwidth organized in multiple RUs. Further, the memory contains instructions executable by said at least one processor, whereby the wireless transmitter is operative to, based on a mapping of the user data to the RUs, demodulate a symbol of the user data from a first set of subcarriers of a first RU of the RUs and redundantly demodulate the symbol from a second set of subcarriers of a second RU of the RUs. The mapping of the user data to the RUs is based on possible puncturing patterns applied to the resource RUs to mute one or more of the resource units in response to detecting intermittent interference.

According to a further embodiment of the invention, a computer program or computer program product is provided, e.g., in the form of a non-transitory storage medium, which comprises program code to be executed by at least one processor of a wireless transmitter. Execution of the program code causes the wireless transmitter to transmit user data using OFDM modulation on a shared wireless medium having a bandwidth organized in multiple RUs. Further, execution of the program code causes the wireless transmitter to, based on a mapping of the user data to the RUs, modulate a symbol of the user data onto a first set of subcarriers of a first resource unit of the RUs and redundantly modulate the symbol onto a second set of subcarriers of a second RU of the RUs. The mapping of the user data to the RUs is based on possible puncturing patterns applied to the RUs to mute one or more of the resource units in response to detecting intermittent interference.

According to a further embodiment of the invention, a computer program or computer program product is provided, e.g., in the form of a non-transitory storage medium, which comprises program code to be executed by at least one processor of a wireless receiver. Execution of the program code causes the wireless receiver to receive user data using OFDM modulation on a shared wireless medium having a bandwidth organized in multiple RUs. Further, execution of the program code causes the wireless receiver to, based on a mapping of the user data to the RUs, demodulate a symbol of the user data from a first set of subcarriers of a first RU of the RUs and redundantly demodulate the symbol from a second set of subcarriers of a second RU of the RUs. The mapping of the user data to the RUs is based on possible puncturing patterns applied to the resource RUs to mute one or more of the resource units in response to detecting intermittent interference.

In the following, concepts in accordance with exemplary embodiments of the invention will be explained in more detail and with reference to the accompanying drawings. The illustrated embodiments relate to controlling of OFDM based wireless transmissions in a wireless communication system. The wireless communication system may be a WLAN (Wireless Local Area Network) system based on a IEEE <NUM> technology, i.e., according to the IEEE <NUM> standards family. However, it is noted that the illustrated concepts could also be applied to other wireless communication technologies, e.g., to the LTE (Long Term Evolution) or NR (New Radio) technology specified by 3GPP (<NUM>rd Generation Partnership Project). The wireless transmissions are from a wireless transmitter to a wireless receiver. By way of example, the wireless transmitter could be an access point (AP) of the wireless communication system and the wireless receiver a station (STA) associated with the AP. Alternatively, the wireless receiver could be an AP of the wireless communication system and the wireless transmitter a STA associated with the AP. In some scenarios, the same device could act both as a wireless transmitter a wireless receiver, e.g., an AP or STA engaged in bidirectional wireless transmissions.

<FIG> illustrates an an example of a wireless communication system. In the illustrated example, the wireless communication system includes multiple APs <NUM>, in the illustrated example referred to as AP1, AP2, AP3, and multiple stations (STAs) <NUM>, in the illustrated example referred to as STA11, STA21, STA22, and STA31. The station STA11 is served by AP1 (in a first BSS denoted as BSS1), the stations STA21 and STA22 are served by AP2 (in a second BSS denoted as BSS2). The station STA31 is served by AP3 (in a third BSS denoted as BSS3). The stations <NUM> may correspond to various kinds of wireless devices, for example user terminals, such as mobile or stationary computing devices like smartphones, laptop computers, desktop computers, tablet computers, gaming devices, or the like. Further, the stations <NUM> could for example correspond to other kinds of equipment like smart home devices, printers, multimedia devices, data storage devices, or the like. Each AP <NUM> may operate as a wireless transmitter, in the case of downlink (DL) transmissions from the AP <NUM> to a station <NUM>, and/or as a wireless receiver, in the case of uplink (UL) transmissions from the station <NUM> to the AP <NUM>. Similarly, station <NUM> may operate as a wireless transmitter, in the case of UL transmissions from the station to an AP <NUM>, and/or as a wireless receiver, in the case of DL transmissions from an AP <NUM> to the station <NUM>.

In the example of <FIG>, each of the stations <NUM> may connect through a radio link to one of the APs <NUM>. For example depending on location or channel conditions experienced by a given station <NUM>, the station <NUM> may select an appropriate AP <NUM> and BSS for establishing the radio link. The radio link may be based on one or more OFDM carriers from a frequency spectrum which is shared on the basis of a contention based mechanism, e.g., an unlicensed band like the <NUM> ISM band, the <NUM> band, the <NUM> band, or the <NUM> band.

Each AP <NUM> may provide data connectivity of the stations <NUM> connected to the AP <NUM>. As further illustrated, the APs <NUM> may be connected to a data network (DN) <NUM>. In this way, the APs <NUM> may also provide data connectivity of stations <NUM> connected to different APs <NUM>. Further, the APs <NUM> may also provide data connectivity of the stations <NUM> to other entities, e.g., to one or more servers, service providers, data sources, data sinks, user terminals, or the like. Accordingly, the radio link established between a given station <NUM> and its serving AP <NUM> may be used for providing various kinds of services to the station <NUM>, e.g., a voice service, a multimedia service, or other data service. Such services may be based on applications which are executed on the station <NUM> and/or on a device linked to the station <NUM>. By way of example, <FIG> illustrates an application service platform <NUM> provided in the DN <NUM>. The application(s) executed on the station <NUM> and/or on one or more other devices linked to the station <NUM> may use the radio link for data communication with one or more other stations <NUM> and/or the application service platform <NUM>, thereby enabling utilization of the corresponding service(s) at the station <NUM>.

In the illustrated concepts, it is assumed that OFDM modulation is utilized for transmissions on a shared wireless medium. A bandwidth of the wireless medium, e.g., in the range of <NUM> to <NUM>, is organized in multiple RUs. Each of the RUs includes multiple subcarriers which can be used in the OFDM modulation. The RUs can be allocated to different users. However, in some situations the entire bandwidth, i.e., all RUs, could also be allocated to a single user. For example, the allocation of the bandwidth could be dynamically or semi-statically changed between configurations where the RUs are allocated to two or more different users, and configurations where the RUs are allocated to a single user.

According to the present invention, based on the OFDM modulation, user data is transmitted from a wireless transmitter to a wireless receiver. For transmitting the user data, the user data may first be encoded, e.g., using an LDPC (Low Density Parity Check Code), to generate a stream or sequence of bits, which is mapped to a first RU and to a second RU. For transmitting the user data, according to the present invention, a symbol of the user data is modulated onto a first set of subcarriers of the first RU and redundantly modulated onto a second set of subcarriers of the second RU. The mapping of the user data to the RUs, i.e., the selection of the first RU and the second RU among the available RUs, is based on possible puncturing patterns applied to the RUs. According to the present invention, the puncturing patterns are applied by the wireless transmitter to mute certain RUs in response to detecting intermittent interference. Accordingly, the transmission of the user data may utilize DCM, with two copies of code bits generated by DCM being mapped to different RUs. The mapping of user data to the RUs is determined in such a way that, in case of puncturing the RUs, at least one of the copies will not be punctured. In this way, gains from DCM can be used to effectively support preamble puncturing.

<FIG> schematically illustrates an example architecture of a wireless transmitter, which may be used for implementing the illustrated concepts, e.g., in any of the above-mentioned APs <NUM> or stations <NUM>. In the example of <FIG>, the wireless transmitter includes a PHY (Physical layer) entity <NUM>, and a MAC entity <NUM>. The MAC entity <NUM> provides a PSDU (PHY Service Data Unit) <NUM> to the PHY entity <NUM>. The PHY entity <NUM> includes an encoder <NUM> and a mapper <NUM>. The encoder <NUM> encodes the PSDU <NUM> provided by the MAC entity <NUM>, e.g., based on an LDPC code. The mapper <NUM> maps the code bits provided by the encoder <NUM> to RUs for modulation of symbols onto subcarriers of the RUs. The operation of the mapper <NUM> in particular involves mapping of a sequence of code bits to a first set of subcarriers in a first one of the RUs, and mapping a copy of the sequence of code bits to a second set of subcarriers in a second one of the RUs. The sequence of code bits is thus redundantly modulated onto the first set of subcarriers and onto the second set of subcarriers, with the first and second set of subcarriers being in different RUs. The operation of the mapper <NUM> thus enables DCM using multiple RUs, in the following also referred to as multi-RU DCM. The mapping of the code bits to RUs as applied by the mapper <NUM> is based on possible puncturing patterns <NUM>, which may be applied to the RUs. For example, the possible puncturing patterns <NUM> could be preconfigured in the wireless transmitter, e.g., by storing a set of allowed puncturing patterns or a set of forbidden puncturing patterns in a memory of the wireless transmitter.

<FIG> schematically illustrates an example architecture of a wireless receiver, which may be used for implementing the illustrated concepts, e.g., in any of the above-mentioned APs <NUM> or stations <NUM>. In the example of <FIG>, the wireless receiver includes a PHY entity <NUM>, and a MAC entity <NUM>. The PHY entity <NUM> includes a demapper <NUM> and a decoder <NUM>. The demapper <NUM> demaps the code bits corresponding to symbols demodulated from subcarriers of the RUs. The operation of the demapper <NUM> in particular involves demapping of a sequence of code bits corresponding to a symbol demodulated from a first set of subcarriers in a first one of the RUs, and demapping a copy of the sequence of code bits corresponding to a symbol demodulated from a second set of subcarriers in a second one of the RUs. In other words, the demapper <NUM> indentifies that the symbol demodulated from the first set of subcarriers and the symbol demodulated from the second set of subcarriers relate to the same sequence of code bits. The sequence of code bits is thus redundantly demodulated from the first set of subcarriers and from the second set of subcarriers, with the first and second set of subcarriers being in different RUs. The decoder <NUM> then decodes the redundantly demodulated code bits, e.g., based on an LDPC code. Various methods may be applied for combining the redundantly demodulated symbols. The PHY entity <NUM> then generates a PSDU <NUM> from the decoded bits and provides the PSDU to the MAC entity <NUM>. The operation of the demapper <NUM> thus enables DCM using multiple RUs, i.e., multi-RU DCM, at the receiver side. The mapping of the code bits to RUs as applied by the demapper <NUM> is based on possible puncturing patterns <NUM>, which may be applied to the RUs. For example, the possible puncturing patterns <NUM> could be preconfigured in the wireless receiver, e.g., by storing a set of allowed puncturing patterns or a set of forbidden puncturing patterns in a memory of the wireless transmitter.

<FIG> illustrates an example of allowed puncturing patterns, which constitute a subset of possible puncturing patterns. Puncturing patterns differing from the allowed puncturing patterns may be considered as forbidden. By such limitation to a set of allowed puncturing patterns, complexity issues, arising for example from the need to signal which RUs have been punctured, may be avoided. In the example of <FIG>, it is assumed that the available OFDM bandwidth is separated into four RUs having the same bandwidth, e.g., <NUM>. The RUs are denoted by RU<NUM>, RU<NUM>, RU<NUM>, and RU<NUM>. The RUs indicated by dashed lines are allowed to be punctured.

When considering that at most <NUM>% of the total bandwidth is allowed to be punctured, it is always possible to configure the mapping to the RUs in such a way that one full copy of the code bits is mapped to non-punctured RUs. This task may be further simplified if some of the possible puncturing patterns are forbidden, e.g., by specifying a set of allowed puncturing patterns like in the example of <FIG> or by specifying a set of forbidden puncturing patterns.

<FIG> schematically illustrates an example of multi-RU DCM based on the illustrated concepts. The example of <FIG> assumes that the available OFDM bandwidth is separated into four RUs having the same bandwidth, e.g., <NUM>. The RUs are denoted by RU<NUM>, RU<NUM>, RU<NUM>, and RU<NUM>. The allowed puncturing patterns may correspond to those as shown in <FIG>. In the illustrated example, the full set of code bits is mapped to RU<NUM> and RU<NUM> while DCM is used to repeat, i.e., redundantly modulate, the code bits in RU<NUM> and RU<NUM>. In this way, it can be ensured that the receiver will get at least one full copy of the code bits, irrespective of whether puncturing is utilized and which puncturing pattern is applied. In the example of <FIG>, k denotes an index of the subcarriers in RU<NUM>, while m denotes an index of the subcarriers in RU<NUM>. As illustrated, the multi-RU DCM modulates code bits onto a set of subcarriers with index k in RU<NUM>, and generates one copy of the code bits which are modulated onto a set of subcarriers with q(k) in RU<NUM>. Here, q(k) may be equal to k. Similarly, the multi-RU DCM the multi-RU DCM modulates code bits onto a set of subcarriers with index m in RU<NUM>, and generates one copy of the code bits which are modulated onto a set of subcarriers with index q(m) in RU<NUM>. Here, q(m) may be equal to m.

<FIG> schematically illustrates a further example of multi-RU DCM based on the illustrated concepts. Similar to the example of <FIG>, the example of <FIG> assumes that the available OFDM bandwidth is separated into four RUs having the same bandwidth, e.g., <NUM>. The RUs are denoted by RU<NUM>, RU<NUM>, RU<NUM>, and RU<NUM>. The allowed puncturing patterns may correspond to those as shown in <FIG>. Also in the example of <FIG>, the full set of code bits is mapped to RU<NUM> and RU<NUM> while DCM is used to repeat, i.e., redundantly modulate, the code bits in RU<NUM> and RU<NUM>. In the example of <FIG>, k denotes an index of the subcarriers in RU<NUM>, while m denotes an index of the subcarriers in RU<NUM>. As illustrated, the multi-RU DCM modulates code bits onto a set of subcarriers with index k in RU<NUM>, and generates one copy of the code bits which are modulated onto a set of subcarriers with index q(k) in RU<NUM>. Here, q(k) may be equal to k. Similarly, the multi-RU DCM the multi-RU DCM modulates code bits onto a set of subcarriers with index m in RU<NUM>, and generates one copy of the code bits which are modulated onto a set of subcarriers with index q(m) in RU<NUM>. Here, q(m) may be equal to m. In the example of <FIG>, the RUs to which the copies of the code bits are mapped are non-adjacent, i.e., there is at least one other RU between these RUs. Accordingly, the distance in the frequency domain between copies of the code bits can be increased as compared to the example of <FIG>, which may yield larger diversity gains in the absence of puncturing.

<FIG> schematically illustrates an example of processes which are based on the above-described concepts. The processes of <FIG> involve an AP <NUM>, e.g., corresponding to any of the above-mentioned Aps <NUM>, and a STA <NUM>, e.g., corresponding to any of the above-mentioned STAs <NUM>.

As illustrated, in the processes of <FIG> the AP <NUM> may receive configuration data <NUM>. The configuration data <NUM> may dynamically or semi-statically configure the AP <NUM> with information indicating allowed puncturing patterns, e.g., as illustrated in <FIG>. Alternatively or in addition, the configuration data <NUM> may dynamically or semi-statically configure the AP <NUM> with information indicating forbidden puncturing patterns. However, it is noted that reception of the configuration data <NUM> is optional and that at least a part of such information indicating allowed puncturing patterns or forbidden puncturing patterns could also be preconfigured in the AP <NUM>.

Further, the STA <NUM> may receive configuration data <NUM>. The configuration data <NUM> may dynamically or semi-statically configure the STA <NUM> with information indicating allowed puncturing patterns, e.g., as illustrated in <FIG>. Alternatively or in addition, the configuration data <NUM> may dynamically or semi-statically configure the STA <NUM> with information indicating forbidden puncturing patterns. However, it is noted that reception of the configuration data <NUM> is optional and that at least a part of such information indicating allowed puncturing patterns or forbidden puncturing patterns could also be preconfigured in the STA <NUM>.

As further illustrated, the AP <NUM> transmits a wireless transmission <NUM> to the STA <NUM>. The wireless transmission <NUM> transmits user data using OFDM modulation on the shared wireless medium, which is organized in multiple RUs. This involves that, based on a mapping of the user data to the resource units, the AP <NUM> modulates symbols of the user data onto a first set of subcarriers of a first RU of the RUs and redundantly modulates the symbols onto a second set of subcarriers of a second RU of the RUs. The mapping of the user data to the RUs is based on possible puncturing patterns applied to the RUs, such as the above-mentioned allowed or forbidden puncturing patterns.

Based on the mapping of the user data to the resource units, the STA <NUM> may then demodulate the symbols of the user data of the wireless transmission <NUM> from the first set of subcarriers and redundantly demodulates the symbol from the second set of subcarriers.

As further illustrated, the STA <NUM> transmits a wireless transmission <NUM> to the AP <NUM>. The wireless transmission <NUM> transmits user data using OFDM modulation on the shared wireless medium, which is organized in multiple RUs. This involves that, based on a mapping of the user data to the resource units, the STA <NUM> modulates symbols of the user data onto a first set of subcarriers of a first RU of the RUs and redundantly modulates the symbols onto a second set of subcarriers of a second RU of the RUs. The mapping of the user data to the RUs is based on possible puncturing patterns applied to the RUs, such as the above-mentioned allowed or forbidden puncturing patterns.

Based on the mapping of the user data to the resource units, the AP <NUM> demodulates the symbol of the user data of the wireless transmission <NUM> from the first set of subcarriers and redundantly demodulates the symbol from the second set of subcarriers.

As can be seen, in the example of <FIG> the AP <NUM> acts as a wireless transmitter for the wireless transmission <NUM>, and the STA <NUM> acts as a wireless receiver for the wireless transmission <NUM>. For the wireless transmission <NUM>, the STA <NUM> acts as a wireless transmitter and the AP <NUM> acts as a wireless receiver. It is noted that in variants of the processes either the wireless transmission <NUM> or the wireless transmission <NUM> could be omitted.

<FIG> shows a flowchart for illustrating a method, which may be utilized for implementing the illustrated concepts. The method of <FIG> may be used for implementing the illustrated concepts in a wireless transmitter for operation in a wireless communication system. The wireless communication system may be based on a wireless local area network, WLAN, technology, e.g., according to the IEEE <NUM> standards family. The wireless transmitter may for example correspond to or be part of any of the above APs <NUM>. Alternatively, the wireless transmitter could for example correspond to or be part of any of the above stations <NUM>. In the method of <FIG>, it assumed that a shared wireless medium, e.g., a carrier from an unlicensed frequency spectrum, is utilized for wireless transmissions based on OFDM modulation. A bandwidth of the shared wireless medium is organized in multiple RUs. The multiple RUs can be allocated to different users, and OFDMA could be used for sharing the wireless medium. However, in some scenarios the RUs could also be allocated to a single user.

If a processor-based implementation of the wireless transmitter is used, at least some of the steps of the method of <FIG> may be performed and/or controlled by one or more processors of the wireless transmitter. Such wireless transmitter may also include a memory storing program code for implementing at least some of the below described functionalities or steps of the method of <FIG>.

At step <NUM>, the wireless transmitter may determine possible puncturing patterns. The puncturing patterns are applied by the wireless transmitter to mute certain RUs in response to detecting intermittent interference. This may for example be based on information indicating allowed puncturing patterns, e.g., as illustrated in <FIG>. At least a part of the information indicating the allowed puncturing patterns can be preconfigured in the wireless transmitter. Alternatively or in addition at least a part of the information indicating the allowed puncturing patterns could be dynamically or semi-statically configured by configuration data provided to the wireless transmitter. Alternatively or in addition, the wireless transmitter may determine the possible puncturing patterns based on information indicating forbidden puncturing patterns. At least a part of the information indicating the forbidden puncturing patterns can be preconfigured in the wireless transmitter. Alternatively or in addition at least a part of the information indicating the forbidden puncturing patterns could be dynamically or semi-statically configured by configuration data provided to the wireless transmitter.

At step <NUM>, the wireless transmitter may determine interference levels on the RUs. This may involve that the wireless transmitter performs measurements on the RUs and/or receives information on interference levels on the RUs.

At step <NUM>, the wireless transmitter may determine a mapping of user data to the RUs. The mapping is based on possible puncturing patterns applied to the RUs to mute certain RUs in response to detecting intermittent interference, e.g., as determined at step <NUM>. Further, the mapping may be based on interference levels on the RUs, e.g., as determined at step <NUM>. By considering the interference levels, it can be taken into account that RUs with high interference level, e.g., with an interference level above a certain threshold have a higher likelihood of being subject to puncturing.

Accordingly, the method may utilize a mapping of the user data to the RUs, which is based on possible puncturing patterns applied to the RUs, in particular on allowed puncturing patterns and/or forbidden puncturing patterns. Further, the mapping may be based on interference levels on the RUs.

At step <NUM>, the wireless transmitter transmits the user data on the wireless medium, using OFDM modulation. This involves modulating the user data onto subcarriers of the shared medium in accordance with step <NUM>.

At step <NUM>, the wireless transmitter modulates a symbol of the user data onto a first set of subcarriers of a first RU of the RUs and redundantly modulates the symbol onto a second set of subcarriers of a second RU of the RUs, e.g., based on DCM. This is accomplished based on the above mapping of the user data to the RUs. In particular, the mapping determines selection of the first RU and the second RU. The mapping of the user data to the RUs may be configured to prevent that both the first RU and the second RU are subject to puncturing.

<FIG> shows a block diagram for illustrating functionalities of an wireless transmitter <NUM> which operates according to the method of <FIG>. The wireless transmitter <NUM> may for example correspond to one of above-mentioned APs <NUM> or stations <NUM>. As illustrated, the wireless transmitter <NUM> may optionally be provided with a module <NUM> configured to determine possible puncturing patterns, such as explained in connection with step <NUM>. Further, the wireless transmitter <NUM> may optionally be provided with a module <NUM> configured to determine interference levels, such as explained in connection with step <NUM>. Further, the wireless transmitter <NUM> may optionally be provided with a module <NUM> configured to determine a mapping of user data to RUs, such as explained in connection with step <NUM>. Further, the wireless transmitter <NUM> may be provided with a module <NUM> configured to transmit user data, such as explained in connection with step <NUM>. Further, the wireless transmitter <NUM> may be provided with a module <NUM> configured to modulate a symbol of the user data to a first set of subcarriers and to a second set of subcarriers, such as explained in connection with step <NUM>.

It is noted that the wireless transmitter <NUM> may include further modules for implementing other functionalities, such as known functionalities of WLAN AP or WLAN station. Further, it is noted that the modules of the wireless transmitter <NUM> do not necessarily represent a hardware structure of the wireless transmitter <NUM>, but may also correspond to functional elements, e.g., implemented by hardware, software, or a combination thereof.

<FIG> shows a flowchart for illustrating a method, which may be utilized for implementing the illustrated concepts. The method of <FIG> may be used for implementing the illustrated concepts in a wireless receiver for operation in a wireless communication system. The wireless communication system may be based on a wireless local area network, WLAN, technology, e.g., according to the IEEE <NUM> standards family. The wireless receiver may for example correspond to or be part of any of the above APs <NUM>. Alternatively, the wireless receiver could for example correspond to or be part of any of the above stations <NUM>. In the method of <FIG>, it assumed that a shared wireless medium, e.g., a carrier from an unlicensed frequency spectrum, is utilized for wireless transmissions based on OFDM modulation. A bandwidth of the shared wireless medium is organized in multiple RUs. The multiple RUs can be allocated to different users, and OFDMA could be used for sharing the wireless medium. However, in some scenarios the RUs could also be allocated to a single user.

If a processor-based implementation of the wireless receiver is used, at least some of the steps of the method of <FIG> may be performed and/or controlled by one or more processors of the wireless receiver. Such wireless receiver may also include a memory storing program code for implementing at least some of the below described functionalities or steps of the method of <FIG>.

At step <NUM>, the wireless receiver may determine possible puncturing patterns. This may for example be based on information indicating allowed puncturing patterns, e.g., as illustrated in <FIG>. At least a part of the information indicating the allowed puncturing patterns can be preconfigured in the wireless receiver. Alternatively or in addition at least a part of the information indicating the allowed puncturing patterns could be dynamically or semi-statically configured by configuration data provided to the wireless receiver. Alternatively or in addition, the wireless receiver may determine the possible puncturing patterns based on information indicating forbidden puncturing patterns. At least a part of the information indicating the forbidden puncturing patterns can be preconfigured in the wireless receiver. Alternatively or in addition at least a part of the information indicating the forbidden puncturing patterns could be dynamically or semi-statically configured by configuration data provided to the wireless receiver.

At step <NUM>, the wireless receiver may determine interference levels on the RUs. This may involve that the wireless receiver performs measurements on the RUs and/or receives information on interference levels on the RUs.

At step <NUM>, the wireless receiver may determine a mapping of user data to the RUs. The mapping is based on possible puncturing patterns applied to the RUs to mute certain RUs in response to detecting intermittent interference, e.g., as determined at step <NUM>. Further, the mapping may be based on interference levels on the RUs, e.g., as determined at step <NUM>. By considering the interference levels, it can be taken into account that RUs with high interference level, e.g., with an interference level above a certain threshold have a higher likelihood of being subject to puncturing.

At step <NUM>, the wireless transmitter receives the user data from the wireless medium, using OFDM modulation. This involves demodulating the user data from subcarriers of the shared medium in accordance with step <NUM>.

At step <NUM>, the wireless receiver demodulates a symbol of the user data from a first set of subcarriers of a first RU of the RUs and redundantly demodulates the symbol from a second set of subcarriers of a second RU of the RUs, e.g., based on DCM. This is accomplished based on the above mapping of the user data to the RUs. In particular, the mapping determines selection of the first RU and the second RU. The mapping of the user data to the RUs may be configured to prevent that both the first RU and the second RU are subject to puncturing.

<FIG> shows a block diagram for illustrating functionalities of an wireless receiver <NUM> which operates according to the method of <FIG>. The wireless receiver <NUM> may for example correspond to one of above-mentioned APs <NUM> or stations <NUM>. As illustrated, the wireless receiver <NUM> may optionally be provided with a module <NUM> configured to determine possible puncturing patterns, such as explained in connection with step <NUM>. Further, the wireless receiver <NUM> may optionally be provided with a module <NUM> configured to determine interference levels, such as explained in connection with step <NUM>. Further, the wireless receiver <NUM> may optionally be provided with a module <NUM> configured to determine a mapping of user data to RUs, such as explained in connection with step <NUM>. Further, the wireless receiver <NUM> may be provided with a module <NUM> configured to receive user data, such as explained in connection with step <NUM>. Further, the wireless receiver <NUM> may be provided with a module <NUM> configured to demodulate a symbol of the user data from a first set of subcarriers and from a second set of subcarriers, such as explained in connection with step <NUM>.

It is noted that the wireless receiver <NUM> may include further modules for implementing other functionalities, such as known functionalities of WLAN AP or WLAN station. Further, it is noted that the modules of the wireless receiver <NUM> do not necessarily represent a hardware structure of the wireless receiver <NUM>, but may also correspond to functional elements, e.g., implemented by hardware, software, or a combination thereof.

It is noted that the functionalities as described in connection with <FIG> could also be combined. For example, the same AP could operate as a wireless transmitter according to the method of <FIG> and as a wireless receiver according to the method of <FIG>. Similarly, the same station could operate as a wireless transmitter according to the method of <FIG> and as a wireless receiver according to the method of <FIG>. Further, the functionalities as described in connection with <FIG> could also be combined in a system including a wireless transmitter operating according to the method of <FIG> and a wireless receiver operating according to the method of <FIG>.

<FIG> illustrates a processor-based implementation of a wireless transmitter <NUM> which may be used for implementing the above-described concepts. For example, the structures as illustrated in <FIG> may be used for implementing the concepts in any of the above-mentioned APs <NUM> or stations <NUM>.

As illustrated, the wireless transmitter <NUM> includes one or more radio interfaces <NUM>. The radio interface(s) <NUM> may for example be based on a WLAN technology, e.g., according to an IEEE <NUM> family standard. However, other wireless technologies could be supported as well, e.g., the LTE technology or the NR technology. The radio interface(s) <NUM> may be based on multiple antennas of the wireless transmitter <NUM>.

Further, the wireless transmitter <NUM> may include one or more processors <NUM> coupled to the radio interface(s) <NUM> and a memory <NUM> coupled to the processor(s) <NUM>. By way of example, the radio interface(s) <NUM>, the processor(s) <NUM>, and the memory <NUM> could be coupled by one or more internal bus systems of the access point <NUM>. The memory <NUM> may include a Read-Only-Memory (ROM), e.g., a flash ROM, a Random Access Memory (RAM), e.g., a Dynamic RAM (DRAM) or Static RAM (SRAM), a mass storage, e.g., a hard disk or solid state disk, or the like. As illustrated, the memory <NUM> may include software <NUM> and/or firmware <NUM>. The memory <NUM> may include suitably configured program code to be executed by the processor(s) <NUM> so as to implement the above-described functionalities for controlling wireless transmissions, such as explained in connection with <FIG> and <FIG>.

It is to be understood that the structures as illustrated in <FIG> are merely schematic and that the wireless transmitter <NUM> may actually include further components which, for the sake of clarity, have not been illustrated, e.g., further interfaces or further processors. Also, it is to be understood that the memory <NUM> may include further program code for implementing known functionalities of a WLAN AP or WLAN station. According to some embodiments, also a computer program may be provided for implementing functionalities of the wireless transmitter <NUM>, e.g., in the form of a physical medium storing the program code and/or other data to be stored in the memory <NUM> or by making the program code available for download or by streaming.

<FIG> illustrates a processor-based implementation of a wireless receiver <NUM> which may be used for implementing the above-described concepts. For example, the structures as illustrated in <FIG> may be used for implementing the concepts in any of the above-mentioned APs <NUM> or stations <NUM>.

As illustrated, the wireless receiver <NUM> includes one or more radio interfaces <NUM>. The radio interface(s) <NUM> may for example be based on a WLAN technology, e.g., according to an IEEE <NUM> family standard. However, other wireless technologies could be supported as well, e.g., the LTE technology or the NR technology. The radio interface(s) <NUM> may be based on multiple antennas of the wireless receiver <NUM>.

Further, the wireless receiver <NUM> may include one or more processors <NUM> coupled to the radio interface(s) <NUM> and a memory <NUM> coupled to the processor(s) <NUM>. By way of example, the radio interface(s) <NUM>, the processor(s) <NUM>, and the memory <NUM> could be coupled by one or more internal bus systems of the access point <NUM>. The memory <NUM> may include a ROM, e.g., a flash ROM, a RAM, e.g., a DRAM or SRAM, a mass storage, e.g., a hard disk or solid state disk, or the like. As illustrated, the memory <NUM> may include software <NUM> and/or firmware <NUM>. The memory <NUM> may include suitably configured program code to be executed by the processor(s) <NUM> so as to implement the above-described functionalities for controlling wireless transmissions, such as explained in connection with <FIG> and <FIG>.

It is to be understood that the structures as illustrated in <FIG> are merely schematic and that the wireless receiver <NUM> may actually include further components which, for the sake of clarity, have not been illustrated, e.g., further interfaces or further processors. Also, it is to be understood that the memory <NUM> may include further program code for implementing known functionalities of a WLAN AP or WLAN station. According to some embodiments, also a computer program may be provided for implementing functionalities of the wireless receiver <NUM>, e.g., in the form of a physical medium storing the program code and/or other data to be stored in the memory <NUM> or by making the program code available for download or by streaming.

As can be seen, the concepts as described above may be used for efficiently controlling OFDM based wireless transmissions with redundant utilization of multiple carriers, in particular OFDM based transmissions utilizing DCM and preamble puncturing. More specifically, the illustrated concepts may enable efficient use of unlicensed spectrum by enabling the use of preamble puncturing for DCM. Further, since DCM duplicates the code bits, combining DCM with the channel code, e.g., an LDPC, the code rate is effectively halved. For example, the concatenation of existing channel codes, e.g., such as LDPC codes, and DCM may yield effective code rates as low as <NUM>/<NUM>. Accordingly, the illustrated concepts may also be used to increase the robustness of a punctured transmission, without a need to design, evaluate and implement new, low-rate codes. Rather, the existing codes can be re-used. Further, the illustrated concepts can be implemented with low complexity.

Claim 1:
A method of controlling wireless transmissions in a wireless communication system, the method comprising:
a wireless transmitter (<NUM>,<NUM>; <NUM>; <NUM>) transmitting user data using Orthogonal Frequency Division Multiplexing, OFDM, modulation on a shared wireless medium having a bandwidth organized in multiple resource units;
based on a mapping of the user data to the resource units, the wireless transmitter (<NUM>,<NUM>; <NUM>; <NUM>) modulating a symbol of the user data onto a first set of subcarriers of a first resource unit of the resource units and redundantly modulating the symbol onto a second set of subcarriers of a second resource unit of the resource units,
wherein the mapping of the user data to the resource units is based on possible puncturing patterns applied to the resource units to mute one or more of the resource units in response to detecting intermittent interference.