Demodulation reference signal configuration

Abstract

Disclosed are methods, systems, and computer-readable media for performing operations including generating a mapping pattern including a frequency division orthogonal cover code of length four (FD-OCC4), the mapping pattern for mapping a demodulation reference signal (DMRS) in frequency to a plurality of resource elements in at least one orthogonal frequency division multiplexing (OFDM) symbol, the DMRS being associated with a plurality of DMRS ports; mapping the DMRS to a plurality of resource elements in the at least one OFDM symbol using the FD-OCC4; and transmitting a transmission including the at least one OFDM symbol.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Application No. 63 / 422,895, filed November 4, 2022, entitled "DEMODULATION REFERENCE SIGNAL CONFIGURATIONS," the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to methods and systems for demodulation reference signal (DMRS) configuration. [Background technology]

[0003] A wireless communication network provides an integrated communications platform and telecommunications services to wireless user devices, sometimes referred to as user equipment (UE). Exemplary telecommunications services include telephony, data (e.g., voice, audio, and / or video data), messaging, Internet access, and / or other services. A wireless communication network has radio access nodes that exchange radio signals with wireless user devices using radio network protocols, such as those described in various telecommunications standards promulgated by the 3rd Generation Partnership Project (3GPP). Exemplary wireless communication networks include time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal frequency division multiple access (OFDMA) networks, long term evolution (LTE), and fifth generation new radio (5G NR). Wireless communication networks facilitate mobile broadband services using technologies such as OFDM, multiple input multiple output (MIMO), advanced channel coding, massive MIMO, beamforming, and / or other features. [Brief explanation of the drawings]

[0004] [Figure 1A] 1 shows an existing DMRS configuration for Type 1 DMRS. [Figure 1B] 1 shows an existing DMRS configuration for Type 1 DMRS.

[0005] [Figure 1C] 1 shows an existing DMRS configuration for Type 2 DMRS. [Figure 1D] 1 shows an existing DMRS configuration for Type 2 DMRS.

[0006] [Figure 2] 1 illustrates a wireless network according to some embodiments.

[0007] [Figure 3A] 1 illustrates a first extended DMRS configuration for a Type-1 DMRS, according to some implementations. [Figure 3B] 1 illustrates a first extended DMRS configuration for a Type-1 DMRS, according to some implementations. [Figure 3C] 1 illustrates a first extended DMRS configuration for a Type-1 DMRS, according to some implementations.

[0008] [Figure 4] 10 shows a table for DMRS port to DMRS pattern mapping for Type 1 DMRS, according to some implementations.

[0009] [Figure 5A] 1 illustrates a second extended DMRS configuration for Type-2 DMRS, according to some implementations. [Figure 5B] 1 illustrates a second extended DMRS configuration for Type-2 DMRS, according to some implementations.

[0010] [Figure 6] 6 shows a table 600 for DMRS port to DMRS pattern mapping for a Type 2 DMRS, according to some implementations.

[0011] [Figure 7A] 10 illustrates a third extended DMRS configuration for Type-1 DMRS, according to some implementations. [Figure 7B] 10 illustrates a third extended DMRS configuration for Type-1 DMRS, according to some implementations. [Figure 7C] 10 illustrates a third extended DMRS configuration for Type-1 DMRS, according to some implementations.

[0012] [Figure 8] 10 shows another table for DMRS port to DMRS pattern mapping for Type 1 DMRS, according to some implementations.

[0013] [Figure 9] 1 shows a flowchart of an exemplary method, according to some implementations.

[0014] [Figure 10] FIG. 1 illustrates a user equipment (UE) according to some implementations.

[0015] [Figure 11] 1 illustrates an access node according to some implementations. DETAILED DESCRIPTION OF THE INVENTION

[0016] Demodulation Reference Signals (DMRS) are used in wireless communication networks to determine the quality of downlink and uplink channels. For example, DMRS may be transmitted in the uplink (UL) using a Physical Uplink Shared Channel (PUSCH). DMRS and PUSCH are subject to the same transmission conditions (e.g., DMRS and PUSCH are transmitted using the same precoding and antenna port). A base station receiving PUSCH and DMRS knows the sequence transmitted by the DMRS. The base station uses this information and the received DMRS to determine the uplink transmission conditions.

[0017] Currently, wireless communication systems support two types of demodulation reference signals (DMRS): Type 1 DMRS and Type 2 DMRS. Generally, Type 1 DMRS uses a higher density of resource elements in a symbol allocated to the DMRS than Type 2 DMRS. For example, Type 1 DMRS may use 50% of the resource elements in a symbol allocated to the DMRS, while Type 2 DMRS may use 33%. For uplink DMRS, the DMRS type used by the UE may be configured by higher layer parameters received from the base station, such as DMRS-UplinkConfig. For downlink DMRS, the UE determines the DMRS type to be used based on higher layer parameters received from the base station, such as dmrs-Type.

[0018] In line with the above description, a wireless communication system supports two types of demodulation reference signals (DMRSs): Type-1 DMRS and Type-2 DMRS. To transmit a DMRS, the wireless system uses a mapping pattern to map a DMRS port to resource elements of one or more orthogonal frequency division multiplexing (OFDM) symbols. The DMRS from each DMRS port is then transmitted on the resource elements to which the associated DMRS port is mapped. In this disclosure, the mapping pattern is also referred to as a DMRS configuration. In existing wireless systems, the DMRS configuration for Type-1 DMRS uses a frequency-domain orthogonal cover code of length 2 (FD-OCC2) and two code division multiplexing (CDM) groups to map up to four DMRS ports to one symbol. The DMRS configuration for Type-2 DMRS uses FD-OCC2 and three CDM groups to map up to six DMRS ports to one symbol.

[0019] Both DMRS configurations can be extended to two symbols using time-domain OCC of length 2 (TD-OCC2), doubling the number of DMRS ports that can be mapped. Thus, Type 1 DMRS supports up to four DMRS ports in one symbol and up to eight DMRS ports in two symbols. Type 2 DMRS supports up to six DMRS ports in one symbol and up to 12 DMRS ports in two symbols. Supporting multiple DMRS ports allows a single user equipment (UE) to transmit or receive DMRS on multiple transmission layers, for example, using single-user multiple-input multiple-output (SU-MIMO). Furthermore, supporting multiple DMRS ports allows multiple UEs to transmit or receive DMRS using the same resources, for example, using multi-user multiple-input multiple-output (MU-MIMO).

[0020] These existing DMRS configurations are described in Releases 15 / 16 / 17 of Technical Specifications (TS) published by the Third Generation Partnership Project (3GPP). For example, the equations for mapping DMRS in the uplink (UL) are described in 3GPP TS 38.211, Version 16.7.0, Section 6.4.1.1, which are incorporated herein by reference. Also, the equations for mapping DMRS in the downlink (DL) are described in 3GPP TS 38.211, Version 16.7.0, Section 7.4.1.1. These equations are also provided in this disclosure.

[0021] 1A and 1B show an existing DMRS configuration for Type 1 DMRS. Specifically, FIG. 1A shows an example pattern 100 of Type 1 DMRS mapped to resource elements in two symbols. In existing systems, the number of resource elements (also called subcarriers) in one resource block is 12. Therefore, in this example, the number of resource elements available for DMRS in two symbols is 24 resource elements.

[0022] As shown in FIG. 1A, pattern 100 maps two CDM groups to resource elements allocated to a DMRS. Specifically, each CDM group uses two resource elements in the frequency domain and two symbols in the time domain. Pattern 100 may be repeated across other resource elements of the same two symbols. For example, because pattern 100 uses four resource elements in each symbol, the pattern may be repeated two more times in the two symbols.

[0023] 1B shows mapping pattern 100 in more detail. As shown in FIG. 1B, pattern 100 can be used to map up to eight DMRS ports. To do so, pattern 100 uses FD-OCC2 and TD-OCC2 in each CDM group to map up to four DMRS ports across the resource elements allocated for that group. In FIG. 1B, the "+" and "-" in each resource element represent the sign of the Hadamard code used for that resource element.

[0024] 1C and 1D show existing DMRS configurations for a Type-2 DMRS. Specifically, FIG. 1C shows an example pattern 120 of a Type-2 DMRS mapped to resource elements in two symbols. As shown in FIG. 1C, pattern 120 maps three CDM groups across the resource elements allocated for DMRS in the two symbols. Pattern 120 may be repeated across other resource elements in the same two symbols. For example, because pattern 120 uses six resource elements in each symbol, the pattern may be repeated one more time in the two symbols. FIG. 1D shows mapping pattern 120 in more detail. As shown in FIG. 1D, pattern 120 can be used to map up to 12 DMRS ports. To do so, pattern 120 uses FD-OCC2 and TD-OCC2 in each CDM group to map up to four DMRS ports across the resource elements allocated for that group. As in FIG. 1B, the "+" and "-" within each resource element represent the signs of the Hadamard code used for that resource element.

[0025] For Release 18 of the 3GPP standard, 3GPP has agreed to specify a DMRS extension for Cyclic Prefix OFDM (CP-OFDM) that increases the number of supported DMRS ports without increasing DMRS overhead. It was further agreed that there should be a common design between DL and UL DMRS. The DMRS configuration that achieves this DMRS extension has not yet been specified by 3GPP.

[0026] This disclosure describes methods and systems for implementing DMRS extensions that increase the number of DMRS ports supported in uplink and downlink DMRS without increasing DMRS overhead (e.g., by reducing the frequency-domain density of each DMRS port). DMRS extensions include extended DMRS configurations for Type 1 and Type 2 DMRS. Among other benefits, the extended DMRS configurations can at least double the number of DMRS ports supported by existing configurations. As an example, the extended DMRS configurations support up to 16 DMRS ports for Type 1 DMRS and up to 24 DMRS ports for Type 2 DMRS.

[0027] 2 illustrates a wireless network 200 according to some embodiments. The wireless network 200 includes a UE 202 and a base station 204 connected via one or more channels 206A, 206B over an air interface 208. The UE 202 and the base station 204 communicate using a system that supports control for managing the UE 202's access to the network via the base station 204.

[0028] In some implementations, wireless network 200 may be a standalone (SA) network incorporating the fifth generation (5G) New Radio (NR) communication standard defined by the Third Generation Partnership Project (3GPP) technical specifications. In some implementations, wireless network 200 may be a non-standalone (NSA) network that also incorporates Long Term Evolution (LTE). For example, wireless network 200 may be an Evolved Universal Terrestrial Radio Access (E-UTRA)-NR dual connectivity (EN-DC) network or an NR-EUTRA dual connectivity (NE-DC) network. Furthermore, other types of communication standards are possible, including future 3GPP systems (e.g., sixth generation (6G)) systems, Institute of Electrical and Electronics Engineers (IEEE) 802.11 technology, etc. Although aspects may be described herein using terminology commonly associated with 5G NR, aspects of the present disclosure may apply to other systems, such as 4G and / or systems subsequent to 5G (e.g., 6G).

[0029] In wireless network 200, UE 202 and any other UEs in the system may be, for example, laptop computers, smartphones, tablet computers, machine-type devices such as smart meters or dedicated devices for healthcare, intelligent transportation systems, or any other wireless devices with or without a user interface. In network 200, base stations 204 provide UE 202 with network connectivity to a wider network (not shown). This UE 202 connectivity is provided via an air interface 208 within the base station coverage area provided by base station 204. In some implementations, such wider network may be a wide area network operated by a cellular network provider or may be the Internet. Each base station coverage area associated with a base station 204 is supported by an antenna integrated with the base station 204. The coverage area is divided into multiple sectors associated with specific antennas. Such sectors may be physically associated with fixed antennas or may be assigned to a physical area using tunable antennas or antenna settings that can be adjusted in a beamforming process used to direct signals to specific sectors.

[0030] The UE 202 includes a control circuit 210 coupled to a transmit circuit 212 and a receive circuit 214. The transmit circuit 212 and the receive circuit 214 may each be coupled to one or more antennas. The control circuit 210 may include various combinations of application-specific and baseband circuitry. The transmit circuit 212 and the receive circuit 214 may be adapted to transmit and receive data, respectively, and may include radio frequency (RF) circuitry or front-end module (FEM) circuitry.

[0031] In various implementations, aspects of the transmit circuitry 212, receive circuitry 214, and control circuitry 210 may be integrated in various ways to implement the operations described herein. The control circuitry 210 may be adapted or configured to perform various operations, such as those described elsewhere in this disclosure in connection with a UE.

[0032] The transmit circuitry 212 may perform various operations described herein. Additionally, the transmit circuitry 212 may transmit multiple multiplexed uplink physical channels. The multiple uplink physical channels may be multiplexed by time division multiplexing (TDM) or frequency division multiplexing (FDM) with carrier aggregation. The transmit circuitry 212 may be configured to receive block data from the control circuitry 210 for transmission over the air interface 208.

[0033] The receive circuitry 214 can perform various operations described herein. Additionally, the receive circuitry 214 can receive multiple multiplexed downlink physical channels from the air interface 208 and relay the physical channels to the control circuitry 210. The multiple downlink physical channels may be multiplexed using TDM or FDM with carrier aggregation. The transmit circuitry 212 and the receive circuitry 214 can transmit and receive both control data and content data (e.g., messages, images, videos, etc.) structured within data blocks carried by the physical channels.

[0034] 2 also shows a base station 204. In implementations, the base station 204 may be an NG Radio Access Network (RAN) or a 5G RAN, an E-UTRAN, a non-terrestrial cell, or a legacy RAN such as a UTRAN. As used herein, terms such as "NG RAN" may refer to a base station 204 operating in an NR or 5G wireless network 200, and terms such as "E-UTRAN" may refer to a base station 204 operating in an LTE or 4G wireless network 200. The UE 202 utilizes connections (or channels) 206A, 206B, each of which includes a physical communication interface or layer.

[0035] The base station 204 circuitry may include control circuitry 216 coupled to transmit circuitry 218 and receive circuitry 220. The transmit circuitry 218 and receive circuitry 220 may each be coupled to one or more antennas that may be used to facilitate communication over the air interface 208. The transmit circuitry 218 and receive circuitry 220 may be adapted to transmit and receive data, respectively, to any UE connected to the base station 204. The transmit circuitry 218 may transmit downlink physical channels in multiple downlink subframes. The receive circuitry 220 may receive multiple uplink physical channels from various UEs, including the UE 202.

[0036] In FIG. 2, one or more channels 206A, 206B are shown as an air interface for enabling a communicative coupling and may correspond to a cellular communication protocol, such as a 3GPP LTE protocol, an Advanced Long Term Evolution (LTE-A) protocol, an LTE-based access to unlicensed spectrum (LTE-U), a 5G protocol, an NR protocol, an NR-based access to unlicensed spectrum (NR-U) protocol, and / or any of the other communication protocols described herein. In implementations, the UE 202 may directly exchange communication data over the ProSe interface. The ProSe interface may alternatively be referred to as a sidelink (SL) interface and may include one or more logical channels, including, but not limited to, a physical sidelink control channel (PSCCH), a physical sidelink discovery channel (PSDCH), and a physical sidelink broadcast channel (PSBCH).

[0037] In some implementations, a transmitting device, e.g., a UE 202 or a base station 204, is configured to implement one or more extended DMRS configurations. The following description describes a UE 202 as the transmitting device, but the same principles apply to a base station 204 as the transmitting device. Thus, an extended DMRS configuration may apply to both UL and DL DMRS. The transmitting device may be pre-configured (e.g., based on 3GPP standards) to select one of the extended DMRS configurations, or may receive signaling indicating the extended DMRS configuration to use (e.g., the UE receives higher layer signaling from a base station). As described in more detail below, an extended DMRS configuration can at least double the number of DMRS ports supported by existing configurations.

[0038] In some implementations, the UE 202 is configured to use a first extended DMRS configuration for a Type-1 DMRS. The extended configuration uses a length-four FD-OCC (FD-OCC4) and two CDM groups to map DMRS ports to resource elements of one or more symbols allocated for DMRS. The extended configuration supports up to eight DMRS ports in one symbol and up to 16 DMRS ports in two symbols. TD-OCC2 may be used to extend the extended configuration from one symbol to two symbols.

[0039] In some implementations, the UE 202 may be configured with one or more options for a first enhanced DMRS configuration. In the first option, each CDM group is allocated every other resource element in a symbol. This allocation creates a "comb" in which resource elements belonging to the same CDM group are not adjacent in frequency. In the second option, each CDM group is allocated two sets of two resource elements that are adjacent in frequency. In this option, each pair of resource elements that belong to the same CDM group is separated by a pair of resource elements that belong to another CDM group. In the third option, each CDM group is allocated a set of resource elements that are contiguous in frequency.

[0040] 3A, 3B, and 3C show a first extended DMRS configuration for a Type-1 DMRS according to some implementations. In these figures, the first extended DMRS configuration uses an FD-OCC4, two CDM groups, and a TD-OCC2 to map a DMRS port to two symbols. Because a DMRS port is mapped to two symbols, the extended DMRS configuration supports up to 16 DMRS ports. However, as shown in the figures, there are different mapping pattern options. Each figure shows a different option.

[0041] FIG. 3A illustrates a first option 300 for the first enhanced DMRS configuration. As shown in FIG. 3A, each CDM group is allocated to every other resource element within a symbol. This creates a "comb" in which resource elements belonging to the same CDM group are not adjacent in frequency. Thus, as shown in FIG. 3A, in each symbol, the first resource element is allocated to CDM group 0, the second resource element is allocated to CDM group 1, the third resource element is allocated to CDM group 0, and so on. One advantage of this option is that it improves backward compatibility with legacy configurations (e.g., as shown in FIG. 1A). This enables coordinated scheduling between a UE using a legacy configuration and another UE using an enhanced configuration on the same radio frequency resources.

[0042] Figure 3B shows a second option 310 of the first enhanced DMRS configuration. As shown in Figure 3B, in each symbol, each CDM group is allocated two sets of two resource elements that are adjacent in frequency. In this option, each pair of resource elements that belong to the same CDM group is separated by a pair of resource elements that belong to another CDM group. As shown in Figure 3B, in each symbol, a first pair of resource elements is allocated to CDM group 0, and a second pair of resource elements that are adjacent in frequency to the first pair is allocated to CDM group 1. Furthermore, a third pair of resource elements that are adjacent in frequency to the second pair is allocated to CDM group 0, and a fourth pair of resource elements that are adjacent in frequency to the third pair is allocated to CDM group 1.

[0043] 3C shows a third option 320 of the first enhanced DMRS configuration. In this option, the resource elements belonging to each CDM group are arranged contiguously in frequency. As shown in FIG. 3C, in each symbol, the resource elements for CDM group 0 are allocated to a first set of contiguous resource elements, and the resource elements for CDM group 1 are allocated to a second set of contiguous resource elements arranged in frequency after the first set. Note that options 2 and 3 are more robust against frequency-selective fading channels, and option 3 is most robust against frequency-selective fading channels, e.g., channels with large delay spreads.

[0044] In some implementations, the UE 202 is configured to use equations to map a DMRS sequence to resource elements of one or more symbols. As mentioned above, TS 38.211 describes equations for mapping uplink / downlink DMRS to resource elements. These equations include Equation [1], Equation [2], and Equation [3], which are reproduced below. Equations [1] and [2] are used for uplink DMRS, and Equation [3] is used for downlink DMRS.

number

number

[0045] In some implementations, the UE 202 is configured to apply the first enhanced DMRS configuration for the Type-1 DMRS by selecting specific values ​​for these variables to be used in equations [1], [2], and [3].

[0046] 4 shows a table 400 for mapping DMRS ports to DMRS patterns for a Type 1 DMRS, according to some implementations. Table 400 shows the variables \lambda, \delta, W to be used to map up to 16 DMRS ports to two symbols. f (k'), W t Specify the value of (l'). The values ​​of the variables can be used in the formulas specified in TS 38.211, e.g., formulas [1], [2], and [3]. Different options for the first extended DMRS configuration can be achieved by selecting different values ​​of \delta. In particular, in table 400, Z=1 for option 1, Z=2 for option 2, and Z=4 for option 3.

[0047] In some implementations, the FD-OCC4 in table 400 may be generated based on the FD-OCC2 used in an existing DMRS configuration. The existing FD-OCC2 for Type 1 DMRS is shown in Table 1. [Table 1] In one example, to generate the FD-OCC4 values ​​in table 400, the values ​​in Table 1 are first multiplied by matrix {1,1}. This multiplication results in FD-OCC4 values ​​encompassed by bounding box 402 (i.e., the Kronecker product of the two matrices). These FD-OCC4 values ​​correspond to a first set of eight DMRS ports in table 400 (i.e., ports 0 through 7). Next, the values ​​in Table 1 are multiplied by matrix {1,-1}. This multiplication results in FD-OCC4 values ​​encompassed by bounding box 404 (i.e., the Kronecker product of the two matrices). These FD-OCC4 values ​​correspond to a second set of eight DMRS ports (i.e., ports 8 through 15).

[0048] In some implementations, the UE 202 is configured to use a second extended DMRS configuration for a Type-2 DMRS. The extended configuration uses FD-OCC4 and three CDM groups to map the DMRS to resource elements of one or more symbols allocated for the DMRS. The extended configuration supports up to 12 DMRS ports in one symbol and up to 24 DMRS ports in two symbols. TD-OCC2 may be used to extend the extended configuration from one symbol to two symbols.

[0049] In some implementations, the UE 202 may be configured with one or more options for a second enhanced DMRS configuration. In the first option, the resource elements allocated to each CDM group are arranged in a repeating pattern in frequency. In each symbol, the first pair of resource elements is allocated to CDM group 0, the second pair of elements is allocated to CDM group 1, and the third pair of resource elements is allocated to CDM group 2. This pattern is repeated in frequency. In the second option, in each symbol, each CDM group is allocated a set of resource elements that are contiguous in frequency.

[0050] 5A and 5B show a second extended DMRS configuration for a Type-2 DMRS according to some implementations. In these figures, the second extended DMRS configuration uses FD-OCC4, two CDM groups, and is mapped to two symbols using TD-OCC2. Therefore, the extended DMRS configuration supports up to 24 DMRS ports. However, as shown in the figures, there are different options for the mapping pattern. Each figure shows a different option.

[0051] FIG. 5A shows a first option 500 of the second enhanced DMRS configuration. As shown in FIG. 5A, the resource elements allocated to each CDM group are arranged in a repeating pattern in frequency. In each symbol, the first pair of resource elements is allocated to CDM group 0, the second pair of elements is allocated to CDM group 1, and the third pair of resource elements is allocated to CDM group 2. This pattern repeats in frequency. Thus, after the third pair of resource elements allocated to CDM group 2, the fourth pair of resource elements is allocated to CDM group 0, and so on. One advantage of this option is that it improves backward compatibility with legacy configurations (e.g., as shown in FIG. 1A). This enables coordinated scheduling between a UE using a legacy configuration and another UE using an enhanced configuration on the same radio frequency resources.

[0052] Figure 5B shows a second option 510 of the second enhanced DMRS configuration. In this option, the resource elements belonging to each CDM group are arranged contiguously in frequency. As shown in Figure 5B, in each symbol, resource elements for CDM group 0 are allocated to a first set of contiguous resource elements, resource elements for CDM group 1 are allocated to a second set of contiguous resource elements arranged in frequency after the first set, and resource elements for CDM group 2 are allocated to a third set of contiguous resource elements arranged in frequency after the second set. Note that option 2 is more robust to frequency-selective fading channels, e.g., channels with large delay spreads.

[0053] In some implementations, the UE 202 is configured to use equations to map the DMRS sequence to resource elements of one or more OFDM symbols. In some implementations, the UE 202 is configured to apply a second extended DMRS configuration for Type-2 DMRS by selecting particular values ​​for variables in equations described in TS 38.211, e.g., equations [1], [2], and [3].

[0054] 6 shows a table 600 for mapping DMRS ports to DMRS patterns for a Type 2 DMRS, according to some implementations. Table 600 shows the variables \lambda, \delta, W to be used to map up to 24 DMRS ports to two symbols. f (k'), W t Specify the value of (l'). The values ​​of the variables can be used in the formulas specified in TS 38.211, e.g., formulas [1], [2], and [3]. Different options for the first extended DMRS configuration can be achieved by selecting different values ​​of \delta. In particular, in table 600, Z=2 for option 1 and Z=4 for option 2.

[0055] In some implementations, the FD-OCC4 in table 600 may be generated based on the FD-OCC2 used in an existing DMRS configuration. The existing FD-OCC2 for Type 2 DMRS is shown in Table 2. [Table 2] In one example, to generate the FD-OCC4 values ​​in table 600, the values ​​in Table 2 are first multiplied by the matrix {1,1}. This multiplication produces FD-OCC4 values ​​corresponding to a first set of 12 DMRS ports (i.e., ports 0 through 11) in table 600. Next, the values ​​in Table 2 are multiplied by the matrix {1,-1}. This multiplication produces FD-OCC4 values ​​corresponding to a second set of 12 DMRS ports (i.e., ports 12 through 23).

[0056] In some implementations, the UE 202 is configured to use a third extended DMRS configuration for a Type 1 DMRS. The extended configuration uses a length-6 FD-OCC (FD-OCC6), two CDM groups, and a TD-OCC2 to map the DMRS (and associated DMRS ports) to resource elements in the two symbols allocated for the DMRS. The extended configuration supports up to 24 DMRS ports in the two symbols. For this extended DMRS configuration, the FD-OCC6 is based on a cyclic shift code, such as a discrete Fourier transform (DFT) code. The DFT-based FD-OCC6 includes the following six codes: {1, -1, 1, -1, 1, -1}; {1, a 1 ,a 2 ,a 3 ,a 4 ,a 5};{1,a 2 ,a 4 ,a 6 ,a 8 ,a 10};{1,a 4 ,a 8 ,a 12 ,a 16 ,a 20};{1,a 5 ,a 10 ,a 15 ,a 20 ,a 25}, where:

number

[0057] In some implementations, the UE 202 may be configured with one or more options for a third enhanced DMRS configuration. In a first option, each CDM group is allocated every other resource element in a symbol. This allocation creates a "comb" in which resource elements belonging to the same CDM group are not adjacent in frequency. In a second option, each CDM group is allocated two sets of three resource elements that are adjacent in frequency. In this option, each set of three resource elements that belong to the same CDM group is separated by a set of three resource elements that belong to another CDM group. In a third option, each CDM group is allocated a set of resource elements that are contiguous in frequency.

[0058] 7A-7C illustrate a third extended DMRS configuration for Type-1 DMRS according to some implementations. FIG. 7A illustrates a first option 700 of the third extended DMRS configuration. As shown in FIG. 7A, each CDM group is allocated to every other resource element within a symbol. This creates a "comb" in which resource elements belonging to the same CDM group are not adjacent in frequency. Thus, as shown in FIG. 7A, in each symbol, the first resource element is allocated to CDM group 0, the second resource element is allocated to CDM group 1, the third resource element is allocated to CDM group 0, and so on. One advantage of this option is that it improves backward compatibility with legacy configurations (e.g., as shown in FIG. 1A). This enables coordinated scheduling between a UE using a legacy configuration and another UE using an extended configuration on the same radio frequency resources.

[0059] Figure 7B shows a second option 710 of the third enhanced DMRS configuration. As shown in Figure 7B, in each symbol, each CDM group is allocated two sets of three resource elements that are adjacent in frequency. In this option, each set of resource elements that belong to the same CDM group is separated by another set of resource elements that belong to another CDM group. As shown in Figure 7B, in each symbol, a first set of three resource elements is allocated to CDM group 0, and a second set of three resource elements that are adjacent in frequency to the first set is allocated to CDM group 1. Furthermore, a third set of resource elements that are adjacent in frequency to the second set is allocated to CDM group 0, and a fourth set of resource elements that are adjacent in frequency to the third set is allocated to CDM group 1.

[0060] Figure 7C shows a third option 720 of the third enhanced DMRS configuration. In this option, the resource elements belonging to each CDM group are arranged contiguously in frequency. As shown in Figure 7C, in each symbol, the resource elements for CDM group 0 are allocated to a first set of contiguous resource elements, and the resource elements for CDM group 1 are allocated to a second set of contiguous resource elements arranged in frequency after the first set. Note that options 2 and 3 are more robust against frequency-selective fading channels, and option 3 is the most robust against frequency-selective fading channels, e.g., channels with large delay spreads.

[0061] In some implementations, the UE 202 is configured to use equations for mapping a DMRS sequence to resource elements of one or more symbols to achieve the third DMRS configuration shown in Figures 7A-7C. In some implementations, the UE 202 is configured to apply the third extended DMRS configuration for Type-1 DMRS by selecting particular values ​​for variables in equations described in TS 38.211, e.g., equations [1], [2], and [3].

[0062] 8 shows a table 800 for mapping DMRS ports to DMRS patterns for a Type 1 DMRS, according to some implementations. Table 800 shows the variables \lambda, \delta, W to be used to map up to 24 DMRS ports to two symbols. f (k'), W t Specify the value of (l'). The values ​​of the variables can be used in the formulas specified in TS 38.211. Different options for the first extended DMRS configuration can be achieved by selecting different values ​​of \delta. In particular, in table 800, Z=1 for option 1, Z=3 for option 2, and Z=6 for option 3.

[0063] 9 illustrates a flowchart of an example method 900 according to some embodiments. For clarity of presentation, the following description generally describes the method 900 in the context of other figures in this description. For example, the method 900 may be performed by the UE 202 or the base station 204 of FIG. 2. It will be understood that the method 900 may be performed by, for example, any suitable system, environment, software, hardware, or combination of systems, environments, software, and hardware, as desired. In some implementations, various steps of the method 900 may be performed in parallel, in combination, in a loop, or in any order.

[0064] In step 902, the method 900 includes generating a mapping pattern comprising a frequency division orthogonal cover code of length 4 (FD-OCC 4), the mapping pattern for mapping a demodulation reference signal (DMRS) in frequency to a plurality of resource elements in at least one orthogonal frequency division multiplexing (OFDM) symbol, where the DMRS is associated with a plurality of DMRS ports.

[0065] At step 904, the method 900 includes mapping the DMRS to a plurality of resource elements in at least one OFDM symbol using FD-OCC 4.

[0066] In step 906, the method 900 includes sending a transmission including at least one OFDM symbol.

[0067] In some implementations, the at least one OFDM symbol is two OFDM symbols.

[0068] In some implementations, the mapping pattern further includes a time division OCC of length 2 (TD-OCC 2) that temporally maps the DMRS to two OFDM symbols.

[0069] In some implementations, the mapping pattern further includes a plurality of code division multiplexing (CDM) groups, each of the plurality of CDM groups being associated with a respective subset of the plurality of DMRS ports.

[0070] In some implementations, using FD-OCC 4, mapping a DMRS to multiple resource elements includes mapping the DMRS such that DMRSs associated with the same CDM group are not mapped to adjacent resource elements in frequency.

[0071] In some implementations, using FD-OCC 4, mapping a DMRS to multiple resource elements includes mapping the DMRS such that DMRSs associated with the same CDM group are mapped to adjacent resource elements in frequency.

[0072] In some implementations, DMRSs associated with the same CDM group are mapped to contiguous resource elements in frequency.

[0073] In some implementations, the number of CDM groups is 2 or 3. In some implementations, a different number of CDM groups is used.

[0074] In some implementations, the at least one OFDM symbol is two OFDM symbols and the number of DMRS ports is 16 or 24. In some implementations, a different number of DMRS ports is used.

[0075] In some implementations, the at least one OFDM symbol is one OFDM symbol and the number of DMRS ports is 8 or 12. In some implementations, a different number of DMRS ports is used.

[0076] In some implementations, the mapping pattern repeats in frequency.

[0077] In some implementations, the DMRS is one of a Type 1 DMRS or a Type 2 DMRS.

[0078] In some implementations, generating the mapping pattern includes determining a first table representing a length-two FD-OCC (FD-OCC2) DMRS configuration, the first table including X rows, each row including an individual FD-OCC2 for a corresponding DMRS port, and generating a second table representing an FD-OCC4 using the first table. The second table is generated by multiplying an individual FD-OCC2 from each corresponding row in the first table by a {1,1} matrix to generate a first set of X rows of the second table, and by multiplying an individual FD-OCC2 from each corresponding row in the first table by a {1,-1} matrix to generate a second set of X rows of the second table.

[0079] In some implementations, the first table is: [Table 3]

[0080] In some implementations, the first table is: [Table 4]

[0081] 10 illustrates a UE 1000 according to some embodiments. The UE 1000 may be similar to and substantially interchangeable with 202 in FIG.

[0082] The UE1000 may be any mobile or non-mobile computing device, such as a mobile phone, a computer, a tablet, an industrial wireless sensor (e.g., a microphone, a pressure sensor, a thermometer, a motion sensor, an accelerometer, an inventory sensor, a voltage / current meter, etc.), a video device (e.g., a camera, a video camera, etc.), a wearable device (e.g., a smart watch), a relaxed-IoT device, etc.

[0083] The UE 1000 may include a processor 1002, an RF interface circuit 1004, memory / storage 1006, a user interface 1008, sensors 1010, a driver circuit 1012, a power management integrated circuit (PMIC) 1014, one or more antennas 1016, and a battery 1018. The components of the UE 1000 may be implemented as an integrated circuit (IC), portions thereof, separate electronic devices or other modules, logic, hardware, software, firmware, or a combination thereof. The block diagram of FIG. 10 is intended to illustrate a high-level view of some of the components of the UE 1000. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other embodiments.

[0084] The components of UE 1000 may be coupled with various other components via one or more interconnects 1020, which may represent any type of interface, input / output, bus (local, system, or extended), transmission line, trace, optical connection, etc., that allows various circuit components (on a common or different chips or chipsets) to interact with one another.

[0085] The processor 1002 may include processor circuitry such as, for example, a baseband processor circuit (BB) 1022A, a central processor unit circuit (CPU) 1022B, and a graphics processor unit circuit (GPU) 1022C. The processor 1002 may include any type of circuitry or processor circuitry that executes or otherwise operates computer-executable instructions, such as program code, software modules, or functional processes, from memory / storage 1006 to cause the UE 1000 to perform the operations described herein.

[0086] In some implementations, the processor 1002 is configured to generate a mapping pattern comprising a frequency division orthogonal cover code of length 4 (FD-OCC 4), the mapping pattern for mapping a demodulation reference signal (DMRS) in frequency to a plurality of resource elements in at least one orthogonal frequency division multiplexing (OFDM) symbol, the DMRS being associated with a plurality of DMRS ports. The processor 1002 is configured to map the DMRS to a plurality of resource elements in the at least one OFDM symbol using the FD-OCC 4. Further, the processor 1002 is configured to transmit a transmission comprising the at least one OFDM symbol.

[0087] In some implementations, the baseband processor circuit 1022A can access a communications protocol stack 1024 in the memory / storage 1006 to communicate over a 3GPP-compatible network. Generally, the baseband processor circuit 1022A can access a communications protocol stack to perform user plane functions at the physical (PHY) layer, medium access control (MAC) layer, radio link control (RLC) layer, packet data convergence protocol (PDCP) layer, service data adaptation protocol (SDAP) layer, and PDU layer, and control plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, RRC layer, and non-access stratum layer. In some implementations, PHY layer operations may additionally / alternatively be performed by components of the RF interface circuit 1004. The baseband processor circuit 1022A may generate or process baseband signals or waveforms that carry information within a 3GPP-compliant network. In some implementations, waveforms for NR may be based on cyclic prefix orthogonal frequency division multiplexing (OFDM) "CP-OFDM" in the uplink or downlink and discrete Fourier transform spread OFDM "DFT-S-OFDM" in the uplink.

[0088] The memory / storage 1006 may include one or more non-transitory computer-readable media containing instructions (e.g., communication protocol stack 1024) that may be executed by one or more of the processors 1002 to cause the UE 1000 to perform various operations described herein. The memory / storage 1006 includes any type of volatile or non-volatile memory that may be distributed throughout the UE 1000. In some implementations, some of the memory / storage 1006 may be located on the processor 1002 itself (e.g., L1 and L2 caches), while other memory / storage 1006 is external to the processor 1002 but accessible via a memory interface. The memory / storage 1006 may include any suitable volatile or non-volatile memory, such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory, or any other type of memory device technology.

[0089] The RF interface circuitry 1004 may include transceiver circuitry and a radio frequency front end module (RFEM) that enables the UE 1000 to communicate with other devices over a radio access network. The RF interface circuitry 1004 may include various elements disposed in the transmit or receive paths. These elements may include, for example, switches, mixers, amplifiers, filters, combiner circuits, control circuits, etc.

[0090] In the receive path, the RFEM may receive signals radiated from the air interface via one or more antennas 1016 and proceed to filter and amplify the signals (using a low noise amplifier). The signals may be provided to a transceiver receiver that downconverts the RF signals to baseband signals that are provided to a baseband processor of the processor 1002.

[0091] In the transmit path, the transmitter of the transceiver upconverts baseband signals received from the baseband processor and provides RF signals to the RFEM, which may amplify the RF signals through a power amplifier before the signals are radiated over the air interface via the antenna 1016. In various implementations, the RF interface circuitry 1004 may be configured to transmit / receive signals in a manner compatible with NR access technologies.

[0092] The antenna 1016 may include antenna elements for converting electrical signals into radio waves to propagate through the air or for converting received radio waves into electrical signals. The antenna elements may be arranged in one or more antenna panels. The antenna 1016 may have antenna panels that are omnidirectional, directional, or a combination thereof to enable beamforming and multiple-input / multiple-output communications. The antenna 1016 may include microstrip antennas, printed antennas fabricated on the surface of one or more printed circuit boards, patch antennas, phased array antennas, etc. The antenna 1016 may have one or more panels designed for a specific frequency band, including bands in FR1 or FR2.

[0093] User interface circuitry 1008 includes various input / output (I / O) devices designed to enable user interaction with UE 1000. User interface 1008 includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual means for accepting input, including, among others, one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touchscreen, a microphone, a scanner, a headset, etc. Output device circuitry includes any physical or virtual means for displaying or otherwise communicating information, such as sensor readings, actuator position(s), or other similar information. The output device circuitry may include any number or combination of audio or visual displays, including, among other things, one or more simple visual outputs / indicators (e.g., binary status indicators such as light emitting diodes "LEDs" and multi-character visual outputs), or more complex outputs such as display devices or touch screens (e.g., liquid crystal displays "LCDs," LED displays, quantum dot displays, projectors, etc.), and output such as text, graphics, multimedia objects, etc. generated or produced from operation of the UE1000.

[0094] The sensors 1010 may include devices, modules, or subsystems designed to detect events or changes in their environment and transmit information about the detected events (sensor data) to some other device, module, subsystem, etc. Examples of such sensors include, among others, inertial measurement units including accelerometers, gyroscopes, or magnetometers; microelectromechanical or nanoelectromechanical systems including three-axis accelerometers, three-axis gyroscopes, or magnetometers; level sensors; and temperature sensors (e.g., thermistors). These include pressure sensors, image capture devices (e.g., cameras or lensless apertures), light detection and ranging sensors; proximity sensors (e.g., infrared detectors, etc.); depth sensors; ambient light sensors; ultrasonic transceivers; microphones or other similar audio capture devices; and the like.

[0095] The driver circuit 1012 may include software and hardware elements that operate to control particular devices incorporated into, attached to, or otherwise communicatively coupled to the UE 1000. The driver circuit 1012 may include individual drivers that enable other components to interact with or control various input / output (I / O) devices that may be present in or connected to the UE 1000. For example, the driver circuit 1012 may include a display driver for controlling and enabling access to a display device, a touchscreen driver for controlling and enabling access to a touchscreen interface, a sensor driver for obtaining sensor readings of the sensors 1010 and controlling and enabling access to the sensors 1010, drivers for obtaining actuator positions of or controlling and enabling access to electromechanical components, a camera driver for controlling and enabling access to an embedded image capture device, and an audio driver for controlling and enabling access to one or more audio devices.

[0096] The PMIC 1014 may manage the power provided to various components of the UE 1000. In particular, with respect to the processor 1002, the PMIC 1014 may control power source selection, voltage scaling, battery charging, or DC-DC conversion.

[0097] In some implementations, the PMIC 1014 may control or otherwise be a part of various power saving mechanisms of the UE 1000. The battery 1018 may power the UE 1000, although in some examples, the UE 1000 may be mounted and deployed at a fixed location and may have a power source coupled to an electric grid. The battery 1018 may be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, or the like. In some implementations, such as in vehicle-based applications, the battery 1018 may be a typical lead-acid automobile battery.

[0098] 11 illustrates an access node 1100 (e.g., a base station or a gNB) according to some implementations. The access node 1100 may be similar to, and substantially interchangeable with, base station X 104. The access node 1100 may include a processor 1102, an RF interface circuit 1104, a core network (CN) interface circuit 1106, a memory / storage circuit 1108, and one or more antennas 1110.

[0099] The components of the access node 1100 may be coupled to various other components via one or more interconnects 1112. The processor 1102, RF interface circuitry 1104, memory / storage circuitry 1108 (including a communications protocol stack 1114), one or more antennas 1110, and interconnect 1112 may be similar to the similarly named elements shown and described with respect to Figure 10. For example, the processor 1102 may include processor circuits such as a baseband processor circuit (BB) 1116A, a central processing unit circuit (CPU) 1116B, and a graphics processing unit circuit (GPU) 1116C.

[0100] In some implementations, the processor 1102 is configured to generate a mapping pattern comprising a frequency division orthogonal cover code of length 4 (FD-OCC 4), the mapping pattern for mapping a demodulation reference signal (DMRS) in frequency to multiple resource elements in at least one orthogonal frequency division multiplexing (OFDM) symbol, where the DMRS is associated with multiple DMRS ports. The processor 1102 is configured to map the DMRS to multiple resource elements in the at least one OFDM symbol using the FD-OCC 4. Further, the processor 1102 is configured to transmit a transmission including the at least one OFDM symbol.

[0101] The CN interface circuit 1106 can provide connectivity to a core network, e.g., a fifth generation core network (5GC), using a 5GC-compatible network interface protocol, such as Carrier Ethernet Protocol, or some other suitable protocol. Network connectivity may be provided to / from the access node 1100 via optical fiber or wireless backhaul. The CN interface circuit 1106 may include one or more dedicated processors or FPGAs to communicate using one or more of the aforementioned protocols. In some implementations, the CN interface circuit 1106 may include multiple controllers to provide connectivity to other networks using the same or different protocols.

[0102] As used herein, terms such as “access node,” “access point,” and the like may describe equipment that provides wireless baseband functionality for data and / or voice connectivity between a network and one or more users. These access nodes may be referred to as BSs, gNBs, RAN nodes, eNBs, NodeBs, RSUs, TRxPs, or TRPs, and may include terrestrial stations (e.g., terrestrial access points) or satellite stations that provide coverage within a geographic area (e.g., a cell). As used herein, terms such as “NG RAN node” may refer to an access node 1100 (e.g., a gNB) operating in an NR or 5G system, and terms such as “E-UTRAN node” may refer to an access node 1100 (e.g., an eNB) operating in an LTE or 4G system. According to various implementations, the access node 1100 may be implemented as one or more of a dedicated physical device, such as a macrocell base station, and / or a low-power (LP) base station for providing a femtocell, picocell, or other similar cell having a smaller coverage area, lower user capacity, or higher bandwidth compared to a macrocell.

[0103] In some implementations, all or a portion of the access node 1100 may be implemented as one or more software entities running on a server computer as part of a virtual network, sometimes referred to as a CRAN and / or virtual baseband unit pool (vBBUP). In a V2X scenario, the access node 1100 may be or act as a “roadside unit.” The term “roadside unit” or “RSU” may refer to any transportation infrastructure entity used for V2X communications. An RSU may be implemented in or by an appropriate RAN node or a stationary (or relatively stationary) UE; an RSU implemented in or by a UE may be referred to as a “UE-type RSU,” an RSU implemented in or by an eNB may be referred to as an “eNB-type RSU,” an RSU implemented in or by a gNB may be referred to as a “gNB-type RSU,” etc.

[0104] In the description herein, for convenience, various components may be described as performing a task or tasks. Such descriptions should be construed to include the phrase "configured to." It is expressly intended that a description of a component being configured to perform one or more tasks does not invoke 35 U.S.C. 112(f) interpretation with respect to that component.

[0105] For one or more embodiments, at least one of the components depicted in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, or methods as described in the example section below. For example, the baseband circuitry described above in connection with one or more of the foregoing figures may be configured to operate according to one or more of the examples described below. As another example, circuitry associated with a UE, a base station, a network element, etc., as described above in connection with one or more of the foregoing figures, may be configured to operate according to one or more of the examples described below in the example section. Example

[0106] Example 1 includes one or more processors of a transmitting device, the one or more processors causing the transmitting device to perform operations including generating a mapping pattern including a frequency division orthogonal cover code of length four (FD-OCC4), the mapping pattern for mapping a demodulation reference signal (DMRS) in frequency to a plurality of resource elements in at least one orthogonal frequency division multiplexing (OFDM) symbol, the DMRS being associated with a plurality of DMRS ports; mapping the DMRS to a plurality of resource elements in the at least one OFDM symbol using the FD-OCC4; and transmitting a transmission including the at least one OFDM symbol.

[0107] Example 2 is one or more processors of example 1, wherein the at least one OFDM symbol is two OFDM symbols.

[0108] Example 3 is the one or more processors of any of examples 1 or 2, wherein the mapping pattern further includes a time division OCC of length 2 (TD-OCC2) that temporally maps the DMRS to two OFDM symbols.

[0109] Example 4 is one or more processors of any of Examples 1-3, wherein the mapping pattern further includes a plurality of code division multiplexing (CDM) groups, each of the plurality of CDM groups being associated with a distinct subset of the plurality of DMRS ports.

[0110] Example 5 is one or more processors of any of Examples 1-3, wherein the mapping pattern further includes a plurality of code division multiplexing (CDM) groups, each of the plurality of CDM groups being associated with a distinct subset of the plurality of DMRS ports.

[0111] Example 6 is the one or more processors of example 4, wherein mapping the DMRSs to the plurality of resource elements using FD-OCC4 includes mapping the DMRSs such that DMRSs associated with the same CDM group are mapped to adjacent resource elements in frequency.

[0112] Example 7 is one or more processors of example 6, wherein DMRSs associated with the same CDM group are mapped to consecutive resource elements in frequency.

[0113] An eighth embodiment is one or more processors of the fourth embodiment, wherein the number of the plurality of CDM groups is two or three.

[0114] Example 9 is one or more processors according to any of Examples 1 to 8, wherein the at least one OFDM symbol is two OFDM symbols, and the number of the plurality of DMRS ports is 16 or 24.

[0115] Example 10 is one or more processors of example 1, wherein the at least one OFDM symbol is one OFDM symbol, and the number of the plurality of DMRS ports is eight or twelve.

[0116] An eleventh embodiment is one or more processors of any of the first to tenth embodiments, wherein the mapping pattern repeats in frequency.

[0117] A twelfth embodiment is one or more processors according to any one of the first to tenth embodiments, wherein the DMRS is one of a type 1 DMRS or a type 2 DMRS.

[0118] Example 13 is the one or more processors of example 1, wherein generating the mapping pattern includes determining a first table representing a length-2 FD-OCC (FD-OCC2) DMRS configuration, the first table including X rows, each row including an individual FD-OCC2 for a corresponding DMRS port; and generating a second table representing FD-OCC4s using the first table, the second table being generated by: generating a first set of X rows of the second table by multiplying an individual FD-OCC2 from each corresponding row in the first table by a {1,1} matrix; and generating a second set of X rows of the second table by multiplying an individual FD-OCC2 from each corresponding row in the first table by a {1,-1} matrix.

[0119] Example 14 is the one or more processors of example 13, wherein the first table is: [Table 5]

[0120] Example 15 is the one or more processors of example 13, wherein the first table is: [Table 6]

[0121] Example 16 may include a non-transitory computer storage medium encoded with instructions that, when executed by one or more computers, cause the one or more computers to perform any of the operations of Examples 1 to 15.

[0122] Example 17 may include a system including one or more computers and one or more storage devices storing instructions operable, when executed by the one or more computers, to cause the one or more computers to perform any of the operations of Examples 1 to 15.

[0123] Example 18 may include a method for performing the operations of any of Examples 1 to 15.

[0124] Example 19 can include a device including logic, modules, or circuitry for performing one or more elements of the operations described or related to any of Examples 1-15, or any other operations or processes described herein.

[0125] Example 20 may include a method, technique, or process described in or related to the operations of any of Examples 1-15, or a part or portion thereof.

[0126] Example 21 may include an apparatus, e.g., a user device, that includes one or more processors and one or more computer-readable media that include instructions that, when executed by the one or more processors, cause the one or more processors to perform a method, technique, or process described in or related to any of the operations or portions thereof of Examples 1 to 15.

[0127] Example 22 may include a computer program including instructions, where execution of the program by a processing element causes the processing element to perform a method, technique, or process, or a portion thereof, described in or related to any of the operations of Examples 1-15. The operations or actions performed by the instructions executed by the processing element may include any one of the operations of Examples 1-15.

[0128] Example 23 may include a method of communicating in a wireless network as shown and described herein.

[0129] Example 24 may include a system for providing wireless communication as shown and described herein. The operations or actions performed by the system may include the operations of any one of Examples 1 to 15.

[0130] Example 25 may include a device for providing wireless communication as shown and described herein. The operations or actions performed by the device may include the operations of any one of Examples 1 to 15.

[0131] The foregoing operations of Examples 1-15 can be implemented using a computer-implemented method and a computer system including a non-transitory computer-readable medium storing computer-readable instructions for performing the computer-implemented method, and a computer memory interoperably coupled to a hardware processor configured to perform the computer-implemented method or the instructions stored on the non-transitory computer-readable medium.

[0132] Any of the above examples may be combined with any other example (or combination of examples) unless otherwise stated. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise embodiments disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

[0133] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated, and it is intended that the following claims be interpreted to embrace all such variations and modifications.

[0134] It is understood that use of personally identifiable information should comply with generally recognized privacy policies and practices that meet or exceed industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of permitted uses should be clearly indicated to users.

Claims

1. one or more processors of a transmitting device, the one or more processors causing the transmitting device to: generating a mapping pattern including a frequency division orthogonal cover code of length 4 (FD-OCC4), the mapping pattern for mapping a demodulation reference signal (DMRS) in frequency to a plurality of resource elements in at least one orthogonal frequency division multiplexing (OFDM) symbol, the DMRS being associated with a plurality of DMRS ports; Mapping the DMRS to the plurality of resource elements in the at least one OFDM symbol using the FD-OCC4; transmitting a transmission including the at least one OFDM symbol.

2. The one or more processors of claim 1 , wherein the at least one OFDM symbol is two OFDM symbols.

3. 3. The one or more processors of claim 1 or 2, wherein the mapping pattern further comprises a time division OCC of length 2 (TD-OCC2) that temporally maps the DMRS onto the two OFDM symbols.

4. 4. The one or more processors of claim 1, wherein the mapping pattern further comprises a plurality of code division multiplexing (CDM) groups, each of the plurality of CDM groups being associated with a distinct subset of the plurality of DMRS ports.

5. Mapping the DMRS to the plurality of resource elements using the FD-OCC4 The one or more processors of claim 4 , further comprising mapping the DMRSs such that DMRSs associated with the same CDM group are not mapped to adjacent resource elements in frequency.

6. Mapping the DMRS to the plurality of resource elements using the FD-OCC4 The one or more processors of claim 4 , further comprising mapping the DMRSs such that the DMRSs associated with the same CDM group are mapped to adjacent resource elements in frequency.

7. The one or more processors of claim 6 , wherein the DMRSs associated with the same CDM group are mapped to consecutive resource elements in frequency.

8. The one or more processors of claim 4 , wherein the number of the plurality of CDM groups is two or three.

9. 9. The one or more processors of claim 1, wherein the at least one OFDM symbol is two OFDM symbols and the number of the plurality of DMRS ports is 16 or 24.

10. 2. The one or more processors of claim 1, wherein the at least one OFDM symbol is one OFDM symbol and the number of DMRS ports is eight or twelve.

11. The one or more processors of any preceding claim, wherein the mapping pattern repeats in frequency.

12. The one or more processors of any one of claims 1 to 10, wherein the DMRS is one of a Type 1 DMRS or a Type 2 DMRS.

13. generating the mapping pattern includes: determining a first table representing a length-2 FD-OCC (FD-OCC2) DMRS configuration, the first table including X rows, each row including a separate FD-OCC2 for a corresponding DMRS port; and generating a second table representing the FD-OCC4 using the first table, the second table comprising: generating a first set of X rows of the second table by multiplying the individual FD-OCC2s from each corresponding row in the first table by a {1,1} matrix; and generating a second set of X rows of the second table by multiplying the individual FD-OCC2s from each corresponding row in the first table by a {1, -1} matrix.

14. 14. The one or more processors of claim 13, wherein the first table is: Table 1

15. 14. The one or more processors of claim 13, wherein the first table is: Table 2

16. A non-transitory computer storage medium encoded with instructions that, when executed by one or more processors, cause the one or more processors to perform the operations of any one of claims 1 to 15.

17. A system comprising one or more processors according to any one of claims 1 to 15.

18. A method for performing the operations of any one of claims 1 to 15.

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