Frequency diversity technology for single frequency networks

Abstract

Methods, systems, and apparatus for wireless communications are described. Some wireless communication networks may implement aspects of a single frequency network (SFN) that can support multicast and broadcast transmissions. In some cases, a base station may use directional beamforming techniques to transmit a message to a user equipment (UE) using a first frequency configuration of the SFN. The base station may adjust the first frequency configuration to a second frequency configuration and may transmit a retransmission of the message to the UE using the second frequency configuration.

Description

[0001] Cross-references

[0002] This patent application claims priority to U.S. patent application No. 17 / 102,956, filed by BAI et al. on November 24, 2020, entitled “FREQUENCY DIVERSITY TECHNIQUES FOR SINGLE FREQUENCY NETWORKS,” and U.S. provisional patent application No. 62 / 950,832, filed by BAI et al. on December 19, 2019, entitled “FREQUENCY DIVERSITY TECHNIQUES FOR SINGLE FREQUENCY NETWORKS,” each of which is assigned to the assignee of this application. Technical Field

[0003] The following relates generally to wireless communications and, more particularly, to frequency diversity techniques for single frequency networks.

[0004] background

[0005] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, and the like. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems (such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems), and fifth generation (5G) systems, which may be referred to as new radio (NR) systems. These systems may employ various technologies, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations or one or more network access nodes, each base station or network access node simultaneously supporting communication with multiple communication devices, which may be further referred to as user equipment (UE).

[0006] Some wireless communication systems may use single-frequency network (SFN) channels for transmitting data. SFN channels can be used for various types of communications within the system, such as multicast and broadcast communications. Beamformed transmissions can be used to transmit such communications in some scenarios. However, beamformed transmissions can be susceptible to challenges such as short delay spread, narrowband fading, and other issues that can cause interference when a UE receives multicast or broadcast data.

[0007] Overview

[0008] The described techniques relate to improved methods, systems, devices, and apparatuses for supporting frequency diversity techniques for single frequency networks. Generally speaking, the described techniques provide for reducing interference for broadcast transmissions between base stations and user equipment in single frequency network (SFN) channels. In some examples, SFNs can support multicast and broadcast transmissions from various devices in the network.

[0009] In some cases, a base station may communicate with a user equipment (UE) using directional beamforming and may send a broadcast message using a directional beam according to a first frequency configuration of an SFN channel. However, the directional beam may be associated with increased interference at the UE (e.g., due to an interfering broadcast message from another base station), and the UE may transmit a hybrid automatic repeat request (HARQ) feedback message (e.g., a negative acknowledgement (NACK) message) to the base station indicating that the broadcast message was not received correctly or that the broadcast message was not received at all. In some examples, the UE may request a retransmission of the broadcast message using a NACK or by using other signaling, and the UE may be configured to receive the retransmission from the base station. The base station may use various frequency diversity techniques (such as frequency hopping or cyclic diversity delay (CDD) techniques) to adjust the first frequency configuration used to transmit the broadcast message to a second frequency configuration. The base station may transmit the retransmission of the broadcast message using the second frequency configuration of the SFN channel.

[0010] A method of wireless communication at a base station is described. The method may include transmitting a message on a single frequency network channel at a first frequency configuration using a directional beam; adjusting the first frequency configuration to a second frequency configuration different from the first frequency configuration; and transmitting a retransmission of the message on the single frequency network channel at the first frequency configuration.

[0011] An apparatus for wireless communication at a base station is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executed by the processor to cause the apparatus to: transmit a message on a single frequency network channel using a directional beam at a first frequency configuration; adjust the first frequency configuration to a second frequency configuration different from the first frequency configuration; and transmit a retransmission of the message on the single frequency network channel at the second frequency configuration.

[0012] Another apparatus for wireless communication at a base station is described. The apparatus may include means for transmitting a message on a single frequency network channel at a first frequency configuration using a directional beam; adjusting the first frequency configuration to a second frequency configuration different from the first frequency configuration; and transmitting a retransmission of the message on the single frequency network channel at the second frequency configuration.

[0013] A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to: transmit a message on a single frequency network channel at a first frequency configuration using a directional beam; adjust the first frequency configuration to a second frequency configuration that is identical to the first frequency configuration; and transmit a retransmission of the message on the single frequency network channel at the second frequency configuration.

[0014] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, adjusting the first frequency configuration may include operations, features, means, or instructions for: applying a frequency hopping pattern to retransmissions of a message.

[0015] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for transmitting an indication of a frequency hopping pattern.

[0016] In some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein, a first frequency configuration includes a first frequency tuning set allocated for a message, and a second frequency configuration includes a second frequency tuning set allocated for retransmission of the message that may be different from the first frequency tuning set.

[0017] In some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein, adjusting the first frequency configuration may include operations, features, means, or instructions for applying a cyclic diversity delay to retransmissions of the message.

[0018] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for transmitting an indication of a cyclic diversity delay.

[0019] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for receiving a request from a UE to apply a cyclic diversity delay.

[0020] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, applying cyclic diversity delay to retransmissions of a message may include operations, features, means, or instructions for transmitting the message using a first antenna, applying a first phase delay to at least a portion of the message at a second antenna, and transmitting a retransmission of the message based on the first phase delay.

[0021] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for transmitting a second retransmission of the message based on a second phase delay that may be different from the first phase delay.

[0022] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for receiving a negative acknowledgment associated with a message, wherein retransmission of the transmitted message may be based on receiving the negative acknowledgment.

[0023] In some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein, the negative acknowledgement includes a retransmission request associated with the message.

[0024] In some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein, retransmissions may be automatically transmitted.

[0025] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for transmitting a retransmission of the message upon expiration of a gap after transmitting the message.

[0026] In some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein, the message includes a broadcast message.

[0027] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the single frequency network channel includes a multimedia broadcast single frequency network channel.

[0028] A method of wireless communication at a UE is described. The method may include receiving a message on a single frequency network channel in a first frequency configuration using a directional beam, and receiving a retransmission of the message on the single frequency network channel in a second frequency configuration.

[0029] An apparatus for wireless communication at a user equipment terminal (UE) is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executed by the processor to cause the apparatus to: receive a message on a single frequency network channel using a directional beam with a first frequency configuration; and receive a retransmission of the message on the single frequency network channel with a second frequency configuration.

[0030] Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving a message on a single frequency network channel using a directional beam in a first frequency configuration; and receiving a retransmission of the message on the single frequency network channel in a second frequency configuration.

[0031] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: receive a message on a single frequency network channel using a directional beam in a first frequency configuration; and receive a retransmission of the message on the single frequency network channel in a second frequency configuration.

[0032] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for receiving a retransmission of the message according to a frequency hopping pattern, wherein at least the second frequency configuration may be based on the frequency hopping pattern.

[0033] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for receiving an indication of a frequency hopping pattern.

[0034] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for receiving a retransmission of a message from the first node according to a first cyclic diversity delay, wherein at least the second frequency configuration may be based on the first cyclic diversity delay.

[0035] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for receiving an indication of a cyclic diversity delay.

[0036] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for receiving a second retransmission of the message from the first node based on a second cyclic diversity delay that may be different from the first cyclic diversity delay.

[0037] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for receiving a retransmission of the message from the second node according to a third cyclic diversity delay that may be different from the first cyclic diversity delay.

[0038] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for transmitting a request to apply a cyclic diversity delay to a base station.

[0039] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for transmitting a negative acknowledgment associated with the message.

[0040] In some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein, the negative acknowledgement includes a retransmission request associated with the message.

[0041] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for receiving a retransmission of the message upon expiration of a gap after receiving the message. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 An example of a wireless communication system supporting frequency diversity technology for a single frequency network according to aspects of the present disclosure is illustrated.

[0044] Figure 2 An example of a wireless communication system supporting frequency diversity technology for a single frequency network according to aspects of the present disclosure is illustrated.

[0045] Figure 3 Examples of frequency hopping configurations supporting frequency diversity techniques for single frequency networks in accordance with aspects of the present disclosure are illustrated.

[0046] Figure 4 Examples of cyclic diversity delay (CDD) configurations supporting frequency diversity techniques for single frequency networks in accordance with aspects of the present disclosure are illustrated.

[0047] Figure 5 An example of a process flow diagram supporting frequency diversity techniques for a single frequency network in accordance with aspects of the present disclosure is illustrated.

[0048] Figure 6 and 7 A block diagram of a device supporting frequency diversity technology for a single frequency network according to aspects of the present disclosure is shown.

[0049] Figure 8 A block diagram of a communication manager supporting frequency diversity techniques for a single frequency network is shown in accordance with aspects of the present disclosure.

[0050] Figure 9 A diagram of a system including devices supporting frequency diversity technology for a single frequency network is shown in accordance with aspects of the present disclosure.

[0051] Figure 10 and 11 A block diagram of a device supporting frequency diversity technology for a single frequency network according to aspects of the present disclosure is shown.

[0052] Figure 12 A block diagram of a communication manager supporting frequency diversity techniques for a single frequency network is shown in accordance with aspects of the present disclosure.

[0053] Figure 13 A diagram of a system including devices supporting frequency diversity technology for a single frequency network is shown in accordance with aspects of the present disclosure.

[0054] Figures 14 to 18 Shown is a flow chart illustrating a method of supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure.

[0055] Detailed description

[0056] In some wireless communication systems, single frequency network (SFN) channels may be used for various communication types, such as those associated with multicast and broadcast transmissions. In some cases, devices may implement beamforming techniques to transmit messages using SFN channels using directional beams. However, directional beams may be associated with shorter delay spreads, narrowband fading, and increased interference at user equipment (UE), which may be receiving broadcast communications from multiple base stations in the SFN.

[0057] The UE may transmit feedback (e.g., hybrid automatic repeat request (HARQ) feedback, such as a NACK) to the base station to inform the base station that the broadcast message was not correctly received (e.g., only partially received) due to interference, or that the broadcast message was not received at all. In some cases, the UE may transmit a NACK to request retransmission of a broadcast message originally transmitted from the base station or base stations.

[0058] In order to reduce interference and improve the quality of communication, one or more base stations in the network may retransmit broadcast messages by applying various frequency diversity techniques to the retransmissions of the broadcast messages. In one example, the base station(s) may apply frequency hopping to one or more retransmissions of the broadcast message, which may include using one set of frequency tones for the transmission of the broadcast message and another set of frequency tones for the retransmissions of the broadcast message. In another example, the base station may increase the frequency diversity of the retransmissions by applying different cyclic diversity delays to one or more retransmissions of the broadcast message. For example, the base station may transmit the broadcast message on a first frequency tone and may add a cyclic diversity delay to the retransmissions of the broadcast message on a different frequency tone. In such examples, the retransmissions may be cyclically shifted versions of the original broadcast message. Each base station in the SFN may apply a different cyclic diversity delay value to each retransmission. In addition, the cyclic diversity delay value used for the retransmissions may also be different across different base stations.

[0059] One or more base stations may inform the UE of different frequency diversity techniques by transmitting an indication that includes information about the different frequency diversity techniques being used (e.g., frequency hopping, cyclic diversity delay (CDD)). In some cases, the UE may transmit a request to the base station for a specific frequency diversity technique to be used (e.g., as part of a NACK message transmitted by the UE).

[0060] Aspects of the present disclosure are initially described in the context of wireless communication systems. Additional aspects of the present disclosure describe various frequency diversity techniques implemented by a base station to reduce interference with broadcast transmissions to UEs in a SFN. Aspects of the present disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flow charts related to frequency diversity techniques for single frequency networks.

[0061] Figure 1 An example of a wireless communication system 100 supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure is illustrated. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low-latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

[0062] Base stations 105 may be dispersed throughout a geographic area to form wireless communication system 100 and may be different forms of devices or devices with different capabilities. Base stations 105 and UEs 115 may communicate wirelessly via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which UEs 115 and base stations 105 may establish one or more communication links 125. Coverage area 110 may be an example of a geographic area over which base stations 105 and UEs 115 may support signal communication according to one or more radio access technologies.

[0063] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile, or stationary and mobile at different times. The UEs 115 may be different forms of devices or devices with different capabilities. Figure 11. The UE 115 described herein may be capable of communicating with various types of devices, such as other UEs 115, base stations 105, or network equipment (e.g., core network nodes, relays, integrated access and backhaul (IAB) nodes, or other network equipment), such as Figure 1 As shown in .

[0064] Each base station 105 can communicate with the core network 130, with each other, or both. For example, the base stations 105 can interface with the core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3, or another interface). The base stations 105 can communicate with each other directly (e.g., directly between the base stations 105), indirectly (e.g., via the core network 130), or both directly and indirectly over the backhaul links 120 (e.g., via X2, Xn, or other interfaces). In some examples, the backhaul links 120 can be or include one or more wireless links.

[0065] One or more of the base stations 105 described herein may include or may be referred to by one of ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a Node B, an evolved Node B (eNB), a next generation Node B, or a Gigabit Node B (any of which may be referred to as a gNB), a Home Node B, a Home Evolved Node B, or other suitable terminology.

[0066] UE 115 may include or be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where "device" may also be referred to as a unit, a station, a terminal, or a client, etc. UE 115 may also include or be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, etc., which may be implemented in various objects, such as appliances or vehicles, meters, etc.

[0067] The UE 115 described herein may be capable of communicating with various types of devices, such as other UEs 115, which may sometimes act as relays, as well as base stations 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, relay base stations, etc. Figure 1 As shown in .

[0068] The UE 115 and the base station 105 may communicate wirelessly with each other via one or more communication links 125 on one or more carriers. The term "carrier" may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication link 125. For example, a carrier for the communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth portion (BWP)) that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating carrier operation, user data, or other signaling. The wireless communication system 100 may support communication with the UE 115 using carrier aggregation or multi-carrier operation. The UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0069] In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute Radio Frequency Channel Number (EARFCN)) and may be located according to a channel grid for discovery by a UE 115. A carrier may operate in a standalone mode in which initial acquisition and connection may be performed by a UE 115 via the carrier, or a carrier may operate in a non-standalone mode in which the connection is anchored using a different carrier (e.g., a different carrier of the same or different radio access technology).

[0070] The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105, or a downlink transmission from the base station 105 to the UE 115. A carrier may carry downlink or uplink communications (e.g., in FDD mode) or may be configured to carry both downlink and uplink communications (e.g., in TDD mode).

[0071] A carrier may be associated with a particular bandwidth of radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as the "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of several determined bandwidths (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)) of a carrier of a particular radio access technology. Devices of the wireless communication system 100 (e.g., base station 105, UE 115, or both) may have a hardware configuration that supports communication on a particular carrier bandwidth, or may be configurable to support communication on one of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 or UE 115 that supports simultaneous communication via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured to operate on a portion (e.g., a subband, a BWP) or all of the carrier bandwidth.

[0072] The signal waveform transmitted on the carrier may include multiple subcarriers (e.g., using a multicarrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may include one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate of UE 115 can be. Wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers may further improve the data rate or data integrity of communications with UE 115.

[0073] One or more parameter designs for a carrier may be supported, where the parameter designs may include subcarrier spacing (Δf) and cyclic prefix. A carrier may be divided into one or more BWPs with the same or different parameter designs. In some examples, a UE 115 may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time, and communications for the UE 115 may be limited to the one or more active BWPs.

[0074] The time interval of the base station 105 or the UE 115 can be expressed as a multiple of a basic time unit, which can be, for example, a sampling period T s =1 / (Δf max Nf) seconds, where Δf maxNf may represent the maximum supported subcarrier spacing, and Nf may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of communication resources may be organized according to radio frames, each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (e.g., ranging from 0 to 1023).

[0075] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, the frame may be divided into subframes (e.g., in the time domain), and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of codeword periods (e.g., depending on the length of the cyclic prefix added before each codeword period). In some wireless communication systems 100, the time slot may be further divided into a plurality of mini-time slots containing one or more codewords. Excluding the cyclic prefix, each codeword period may include one or more (e.g., Nf) sampling periods. The duration of the codeword period may depend on the subcarrier spacing or the operating frequency band.

[0076] A subframe, slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

[0077] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM), frequency division multiplexing (FDM), or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for physical control channels may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of a carrier. One or more control regions (e.g., CORESETs) may be configured for a set of UEs 115. For example, one or more of UEs 115 may monitor or search the control region for control information according to one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with encoded information for a control information format having a given payload size. The search space sets may include a common search space set configured for transmitting control information to multiple UEs 115 and a UE-specific search space set for transmitting control information to a specific UE 115 .

[0078] Each base station 105 may provide communication coverage via one or more cells (e.g., macro cells, small cells, hotspots, or other types of cells, or any combination thereof). The term "cell" may refer to a logical communication entity used to communicate with a base station 105 (e.g., on a carrier) and may be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or other) used to distinguish between adjacent cells. In some examples, a cell may also refer to a geographic coverage area 110 or a portion of a geographic coverage area 110 (e.g., a sector) on which the logical communication entity operates. The scope of such a cell may range from a smaller area (e.g., a structure, a subset of structures) to a larger area depending on various factors (such as the capabilities of the base station 105). For example, a cell may be or include a building, a subset of buildings, or an external space between or overlapping geographic coverage areas 110, among other examples.

[0079] A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access to UEs 115 that have a service subscription with a network provider that supports the macro cell. A small cell may be associated with a lower power base station 105 (compared to a macro cell), and the small cell may operate in the same or different (e.g., licensed, unlicensed) frequency band as the macro cell. A small cell may provide unrestricted access to UEs 115 that have a service subscription with the network provider, or may provide restricted access to UEs 115 associated with the small cell (e.g., UEs 115 in a closed subscriber group (CSG), UEs 115 associated with users in a home or office). A base station 105 may support one or more cells and may also support communications over one or more cells using one or more component carriers.

[0080] In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that may provide access to different types of devices.

[0081] In some examples, base stations 105 can be mobile and, therefore, provide communication coverage for mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies can overlap, but the different geographic coverage areas 110 can be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies can be supported by different base stations 105. The wireless communication system 100 can include, for example, a heterogeneous network in which different types of base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0082] The wireless communication system 100 may support synchronous or asynchronous operation. For synchronous operation, the base stations 105 may have similar frame timing, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, the base stations 105 may have different frame timing, and transmissions from different base stations 105 may not be aligned in time in some examples. The techniques described herein may be used for either synchronous or asynchronous operation.

[0083] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that incorporate sensors or meters to measure or capture information and relay such information to a central server or application that utilizes the information or presents it to a person interacting with the application. Some UEs 115 may be designed to collect information or implement automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wilderness survival monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0084] Some UEs 115 may be configured to employ a reduced power consumption mode of operation, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception but not simultaneous transmission and reception). In some examples, half-duplex communication may be performed at a reduced peak rate. Other power saving techniques for UEs 115 include entering a power-saving deep sleep mode when not engaged in active communication, operating over a limited bandwidth (e.g., according to narrowband communication), or a combination of these techniques. For example, some UEs 115 may be configured to operate using a narrowband protocol type that is associated with a defined portion or range (e.g., a set of subcarriers or resource blocks (RBs)) within a carrier, within a guard band of a carrier, or outside a carrier.

[0085] The wireless communication system 100 can be configured to support ultra-reliable communication or low-latency communication or various combinations thereof. For example, the wireless communication system 100 can be configured to support ultra-reliable low-latency communication (URLLC) or mission-critical communication. The UE 115 can be designed to support ultra-reliable, low-latency or critical functions (e.g., mission-critical functions). Ultra-reliable communication can include private communication or group communication and can be supported by one or more mission-critical services such as mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData). Support for mission-critical functions can include prioritization of services, and mission-critical services can be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission-critical, and ultra-reliable low-latency can be used interchangeably herein.

[0086] In some examples, UE 115 may also be able to communicate directly with other UEs 115 over a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of base station 105 or otherwise unable to receive transmissions from base station 105. In some examples, groups of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, in which each UE 115 transmits to every other UE 115 in the group. In some examples, base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving base station 105.

[0087] In some systems, the D2D communication link 135 can be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, the vehicles can communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination of these communications. The vehicles can signal information related to traffic conditions, signal scheduling, weather, safety, emergency situations, or any other information related to the V2X system. In some examples, the vehicles in the V2X system can use vehicle-to-network (V2N) communication to communicate with roadside infrastructure (such as roadside units), with the network, or with both via one or more network nodes (e.g., base station 105).

[0088] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), and the EPC or 5GC may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) that manages access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) that routes packets or interconnects to external networks. The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the core network 130. User IP packets may be delivered through the user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to the network operator IP service 150. Operator IP services 150 may include access to the Internet, an intranet, an IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0089] Some network devices (such as base stations 105) may include subcomponents, such as access network entities 140, which may be examples of access node controllers (ANCs). Each access network entity 140 may communicate with each UE 115 through one or more other access network transport entities 145, which may be referred to as radio heads, smart radio heads, or transmit / receive points (TRPs). Each access network transport entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., base station 105).

[0090] The wireless communication system 100 can operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally speaking, the 300 MHz to 3 GHz region is referred to as the ultra-high frequency (UHF) region or the decimeter band because the wavelengths range from approximately 1 decimeter to 1 meter long. UHF waves can be blocked or redirected by buildings and environmental features, but these waves can penetrate various structures sufficiently for macrocells to provide service to UEs 115 located indoors. Transmissions using UHF waves can be associated with smaller antennas and a shorter range (e.g., less than 100 kilometers) compared to transmissions using the lower frequencies and longer wavelengths in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0091] The wireless communication system 100 may also operate in the super high frequency (SHF) region of the frequency band from 3 GHz to 30 GHz (also known as the centimeter band) or in the extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) (also known as the millimeter band). In some examples, the wireless communication system 100 may support millimeter wave (mmW) communications between the UE 115 and the base station 105, and the EHF antennas of the corresponding devices may be smaller and more closely spaced than the UHF antennas. In some examples, this may facilitate the use of antenna arrays within the device. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and a shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions using one or more different frequency regions, and the use of frequency bands specified across these frequency regions may vary by country or regulatory agency.

[0092] The wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may employ licensed assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band, such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in an unlicensed radio frequency spectrum band, devices (such as base stations 105 and UEs 115) may employ carrier sensing for conflict detection and avoidance. In some examples, operations in the unlicensed band may be based on a carrier aggregation configuration (e.g., LAA) in conjunction with component carriers operating in the licensed band. Operations in the unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among others.

[0093] The base station 105 or UE 115 may be equipped with multiple antennas that can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of the base station 105 or UE 115 may be located within one or more antenna arrays or antenna panels that can support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly (such as an antenna tower). In some examples, the antennas or antenna arrays associated with the base station 105 may be located at different geographical locations. The base station 105 may have an antenna array having several rows and columns of antenna ports that the base station 105 can use to support beamforming for communications with the UE 115. Similarly, the UE 115 may have one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support radio frequency beamforming for signals transmitted via the antenna ports.

[0094] The base station 105 or the UE 115 can use MIMO communication to exploit multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such a technique may be referred to as spatial multiplexing. For example, a transmitting device may transmit multiple signals via different antennas or different antenna combinations. Similarly, a receiving device may receive multiple signals via different antennas or different antenna combinations. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO), in which multiple spatial layers are transmitted to the same receiving device, and multi-user MIMO (MU-MIMO), in which multiple spatial layers are transmitted to multiple devices.

[0095] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., base station 105, UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals communicated via antenna elements of an antenna array so that some signals propagating at a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements can include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to the signals carried via the antenna elements associated with that device. The adjustments associated with each antenna element can be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0096] The base station 105 or the UE 115 may use beam sweeping techniques as part of a beamforming operation. For example, the base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with the UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by the base station 105 in different directions. For example, the base station 105 may transmit signals according to different sets of beamforming weights associated with different transmission directions. The transmissions in different beam directions may be used (e.g., by a transmitting device (such as the base station 105) or a receiving device (such as the UE 115)) to identify a beam direction for later transmission or reception by the base station 105.

[0097] Some signals, such as data signals associated with a particular recipient device, may be transmitted by base station 105 in a single beam direction, e.g., a direction associated with a recipient device, such as UE 115. In some examples, a beam direction associated with transmissions along a single beam direction may be determined based on signals transmitted in one or more beam directions. For example, UE 115 may receive one or more signals transmitted by base station 105 in different directions and may report to base station 105 an indication of the signal received by UE 115 with the highest signal quality or other acceptable signal quality.

[0098] In some examples, transmissions by a device (e.g., by a base station 105 or a UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from the base station 105 to the UE 105). The UE 115 may report feedback indicating precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across the system bandwidth or one or more subbands. The base station 105 may transmit reference signals (e.g., cell-specific reference signals (CRS), channel state information reference signals (CSI-RS)) that may be precoded or uncoded. The UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook). Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may use similar techniques to transmit signals multiple times in different directions (e.g., to identify a beam direction for subsequent transmission or reception by UE 115) or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0099] A receiving device (e.g., UE 115) may attempt multiple receive configurations (e.g., directional listening) when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 105. For example, the receiving device may attempt multiple receive directions by receiving via different antenna subarrays, processing received signals according to different antenna subarrays, receiving according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array (e.g., different directional listening weight sets), or processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as "listening" according to different receive configurations or receive directions. In some examples, the receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving data signals). The single receive configuration may be aligned on a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0100] The wireless communication system 100 can be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication of the bearer or packet data convergence protocol (PDCP) layer can be IP-based. The radio link control (RLC) layer can perform packet segmentation and reassembly to communicate on the logical channel. The media access control (MAC) layer can perform priority handling and multiplex the logical channel into the transport channel. The MAC layer can also use error detection technology, error correction technology, or both to support retransmission of the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer can provide the establishment, configuration and maintenance of the RRC connection of the radio bearer that supports user plane data between the UE 115 and the base station 105 or the core network 130. At the physical layer, the transport channel can be mapped to the physical channel.

[0101] UE 115 and base station 105 may support retransmission of data to increase the likelihood that the data is successfully received. Hybrid Automatic Repeat Request (HARQ) feedback is a technique for increasing the likelihood that data is correctly received on communication link 125. HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve MAC layer throughput in poor radio conditions (e.g., low signal-to-noise ratio conditions). In some examples, a device may support simultaneous slot HARQ feedback, wherein the device may provide HARQ feedback in a particular time slot for data received in a previous symbol in that time slot. In other cases, the device may provide HARQ feedback in a subsequent time slot or based on some other time interval.

[0102] In some cases, wireless communication system 100 may be an example of an SFN that can support multicast and broadcast transmissions, as well as other communication types. In some cases, a device (such as base station 105) may use directional beamforming to communicate with UE 115. However, directional beamforming may be associated with increased interference at UE 115.

[0103] In some cases, UE 115 may transmit a NACK to base station 105 indicating that the broadcast message was incorrectly received, or that the broadcast message was not received at all. In some examples, UE 115 may request a retransmission of the broadcast message using a NACK or by using other signaling. In some examples, base station 105 may be configured to automatically send a retransmission of the broadcast message (e.g., even without receiving a NACK from UE 115). To reduce interference and improve communication quality, base station 105 may apply various frequency diversity techniques to the retransmission of the broadcast message. In one example, base station 105 may apply frequency hopping to one or more retransmissions of the broadcast message, which may include using one set of tones for transmission of the broadcast message and another set of tones for retransmissions of the broadcast message. In another example, base station 105 may increase frequency diversity by applying different cyclic diversity delays to one or more retransmissions of the broadcast message transmitted to UE 115. For example, base station 105 may transmit the broadcast message on a first tone and may add a cyclic diversity delay to retransmissions of the broadcast message on a different tone. In such examples, the retransmissions may be cyclically shifted versions of the original broadcast message.Each base station 105 in the SFN may apply a different cyclic diversity delay value to each retransmission.

[0104] Aspects of the present disclosure are initially described in the context of wireless communication systems. Additional aspects of the present disclosure describe various frequency diversity techniques implemented by a base station to reduce interference with broadcast transmissions to UEs in a SFN. Aspects of the present disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flow charts related to frequency diversity techniques for single frequency networks.

[0105] Figure 2 An example of a wireless communication system 200 that supports frequency diversity techniques for a single frequency network according to aspects of the present disclosure is illustrated. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100. The wireless communication system 200 can include base stations 105-a, 105-b, and 105-c and a UE 115-a, which can be as described with reference to FIG. Figure 1 Examples of base stations 105 and UEs 115 are described.

[0106] The wireless communication system 200 may include several base stations 105, each of which simultaneously supports communications for various UEs 115 in the system. In the wireless communication system 200, one or more base stations 105 may transmit downlink data to a UE 115-a or a group of UEs via a communication link 205 to increase the probability that the UE 115-a or the group of UEs successfully receives the downlink data. In some cases, the wireless communication system 200 may include multiple cells 110 as part of a single frequency network (SFN), in which each base station 105 may use the same frequency band to transmit downlink data. In an SFN, a group of UEs can receive the same downlink data by sharing resources used for data transmission. For example, base station 105-a may coordinate with base stations 105-b and 105-c to transmit data using broadcast or multicast techniques within a given dedicated area (e.g., the area of the wireless communication system 200). In such a case, the base station 105 may use a single frequency band to transmit downlink data to the UE 115-a or the group of UEs, thereby conserving resources and improving network efficiency.

[0107] In some wireless communication systems including NR networks (e.g., mmW systems supporting frequencies greater than 24 GHz), various techniques (such as error correction, HARQ, and signal retransmission) can be used to boost the signal-to-noise ratio (SNR) and improve communication reliability.

[0108] Furthermore, feedback (such as ACK / NACK feedback transmitted from a receiving UE) can prompt data retransmissions in a wireless network (e.g., SFN), which can support delay-sensitive and high-reliability applications (e.g., enhanced mobile broadband (eMBB), ultra-reliable and low-latency communication (URLLC)). However, in some cases, a base station 105 may receive acknowledgement (ACK) messages from multiple UEs 115, and the delay in receiving ACK messages from all UEs 115 may be associated with inefficient use of network resources. Additionally or alternatively, a UE 115 may receive a broadcast or multicast message from the base station 105 that may conflict with an ACK / NACK transmission or data retransmission transmitted on an SFN broadcast channel (e.g., such as in the case of narrowband fading). In such cases, techniques (such as multiplexing (e.g., spatial multiplexing, FDM, TDM, etc.), frequency hopping) can be used to increase frequency diversity for retransmissions, and an applied cyclic diversity delay can be employed to make the SFN channel more robust (e.g., more reliable and less susceptible to channel fading). Furthermore, different beam sweeping parameters can be used to send retransmissions in SFN.

[0109] In one example, UE 115 or base station 105 can use directional beamforming to focus energy from a transmission in one or more directions. In some cases, directional beams can be used in conjunction with transmit diversity to improve coverage and signal strength of received transmissions. However, in some other cases, the use of directional beams can shorten the delay spread of the channel and reduce the frequency diversity of the received signal (e.g., channel fading can be more frequency-flat). In some other examples, UE 115 can receive signals from multiple different transmit receive points (TRPs) associated with one or more base stations, and UE 115 can combine received signals from different TRPs or base stations. In such examples, UE 115 can use one or more directional beams to receive data from each TRP.

[0110] In another example, the base station 105 can broadcast data to a group of UEs (e.g., each UE 115 in a cell) using various multiplexing techniques. For example, the base station 105 can transmit the same information in different directions using a TDM / FDM approach using different beams (e.g., using beam sweeping). In some cases, the base station 105 can use spatial multiplexing to transmit different data streams simultaneously on the same frequency. In such cases, the data stream can be transmitted to a single UE 115 to increase the data rate, or the data stream can be transmitted to multiple UEs 115 to increase system capacity. In addition, the network can indicate a relaxed (e.g., increased) initial block error rate (BLER) ratio to increase the capacity of the system while maintaining a threshold quality of service (QoS) for the communication.

[0111] In some cases, UE 115-a may incorrectly receive downlink data from one or more base stations 105 (e.g., the data may be corrupted or incomplete), or UE 115-a may be unable to receive downlink data at all. UE 115-a may attempt various error recovery techniques to recover data that may have been lost during the broadcast / multicast transmission. For example, UE 115-a may transmit HARQ feedback to base station 105-a to notify base station 105-a of an error in the reception of a transmission (e.g., a NACK), or to acknowledge successful reception of a transmission (e.g., an ACK). Base station 105-a may use the HARQ feedback it receives to determine whether to retransmit the downlink data. For example, when base station 105-b receives a NACK from one or more UEs in the network, a retransmission may be triggered (e.g., the retransmission may be triggered by a HARQ process).

[0112] In the example of an SFN, base station 105-a may retransmit the data requested by UE 115-a as a broadcast / multicast transmission to each UE 115. Because base station 105-a transmits to each UE 115 in a broadcast transmission (e.g., not just to UE 115-a), base station 105-a may determine whether to retransmit the data based on various factors (such as a threshold error rate or the number of NACKs received from UEs in the network). In some other scenarios, base station 105-a may autonomously send a retransmission to UE 115-a, and UE 115-a may be configured to expect a retransmission from base station 105-a (e.g., UE 115a may be configured to receive the same information from a broadcast transmission multiple times). In such autonomous retransmissions, the transmission beam used in the later retransmission may be the same beam used for the first transmission of the data.

[0113] In some cases, signals transmitted from one or more base stations in the SFN to the UE 115-a may be subject to interference (e.g., channels at the frequency tones allocated for the SFN may experience poor communication quality). For example, the UE 115-a may be communicating with the base station 105-a and may receive interference associated with other base stations in the network (e.g., the sum of the channels from neighboring base stations may interfere and result in reduced communication quality). In some other examples, self-interference of the network may occur due to transmission delays in broadcasting messages from different base stations in the network to the UE 115-a. In such cases, the UE 115-a may not request a retransmission of the signal because the retransmission may encounter similar challenges as the original transmission (e.g., the retransmission may encounter similar interference from base stations in the SFN that are transmitting simultaneously).

[0114] In order to improve the signal quality associated with broadcast transmissions in the SFN, several different techniques may be applied to reduce the interference impact of retransmissions transmitted to UE 115-a. In some cases, these techniques may allow the SFN channel to have different frequencies on a tone-by-tone basis in the SFN. In one example, the base station 105 may apply frequency hopping to retransmissions in the SFN (e.g., the base station 105 may change the frequency of the tone used to transmit the retransmissions). In another example, the base station 105 may apply a cyclic diversity delay technique to the retransmissions, wherein the base station 105 may apply different cyclic delays to different retransmissions. Additionally, different base stations may apply different cyclic delays to the retransmissions to reduce interference in the SFN. The base station 105 may transmit retransmissions of the broadcast message, and the SFN may have increased transmit diversity and reduced interference impact based on the techniques described herein.

[0115] Figure 3An example of a frequency hopping configuration 300 supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure is illustrated. In some examples, the frequency hopping configuration 300 can implement aspects of the wireless communication system 100. The frequency hopping configuration 300 can include a base station 105-d along with a UE 115-b, which can be as described with reference to FIG. Figure 1 and 2 Examples of base stations 105 and UEs 115 are described.

[0116] Base station 105-d and UE 115-b may communicate using a communication link 305 in an SFN channel. In some cases, communication link 305 may be an example of a broadcast or multicast channel connection in an SFN. Base station 105-d may transmit a broadcast message (e.g., data) to UE 115-b over communication link 305. In some cases, UE 115-b may not be able to receive the broadcast message from base station 105-d, the transmission of the broadcast message may experience interference from other transmissions, or the broadcast message may otherwise be unreceivable by UE 115-b. In such cases, UE 115-b may transmit a NACK to base station 105-d to notify base station 105-d that reception of the broadcast message failed. In some cases, receiving the NACK may trigger base station 105-d to retransmit the broadcast message in a retransmission. In some other cases, base station 105-d may automatically retransmit the broadcast message, and UE 115-b may be configured to receive multiple transmissions of the broadcast message from base station 105-d. In some cases (eg, in the case of automatic retransmission), the transmission and retransmission of a broadcast message may not be contiguous in time.

[0117] Based on the frequency hopping configuration 300, the base station 105-d may use a frequency hopping pattern 310 to reduce interference in the SFN and increase frequency diversity for retransmissions. The base station 105-d may transmit an indication of the frequency hopping pattern 310 to the UE 115-b to indicate different frequency allocations for different retransmissions of the broadcast message. For example, the frequency hopping pattern may be implemented by using different tones for the SFN at different times. The base station 105-d may allocate a first set of tones for transmitting the broadcast message and may allocate a different set of tones for transmitting retransmissions of the broadcast message. In addition, the base station 105-d may use directional beamforming and may transmit multiple different frequencies on the same beam or may transmit using different frequencies on multiple different beams.

[0118] In some examples, base station 105-d may indicate a frequency hopping pattern including several resource allocations 315, 320, and 325 for transmitting retransmissions. Each resource allocation may include a physical downlink control channel (PDCCH) and a demodulation reference signal (DMRS) that schedules a physical downlink shared channel (PDSCH) by using different frequencies for retransmissions. Base station 105-d may transmit a single retransmission or multiple retransmissions based on the frequency hopping pattern it may determine to use. In addition, the indication of the frequency hopping pattern may be communicated to UE 115-c using dynamic signaling, semi-static signaling, or a combination thereof. In some other cases, the indication of the frequency hopping pattern may be known to UE 115-b (e.g., according to a predefined rule).

[0119] Figure 4 An example of a CDD configuration 400 supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure is illustrated. In some examples, the CDD configuration 400 can implement aspects of the wireless communication system 100. The CDD configuration 400 can include a base station 105-e and a UE 115-c, which can be referenced Figure 1-3 Examples of base stations 105 and UEs 115 are described.

[0120] The base station 105-e and the UE 115-c may communicate using a communication link 305 in the SFN. In some cases, the base station 105-e and the UE 115-c may be connected using a broadcast or multicast channel in the SFN. The base station 105-e may transmit a broadcast message to the UE 115-c using a communication link 405. In some cases, the UE 115-c may not be able to receive the broadcast message from the base station 105-e, the broadcast message may experience interference from other transmissions in the SFN (e.g., from other base stations transmitting broadcast messages), or the broadcast message may otherwise be unreceivable by the UE 115-c. In such cases, the UE 115-c may transmit a NACK to the base station 105-e to notify the base station of the failure to receive the broadcast message. In some cases, receiving the NACK may trigger the base station 105-e to retransmit the broadcast message in a retransmission. In some other situations, the base station 105 - e may automatically retransmit the broadcast message, and the UE 115 - c may be configured to receive multiple transmissions of the broadcast message from the base station 105 - e.

[0121] According to the CDD configuration 400, the base station 105-e may use CDD techniques to reduce interference and increase transmit diversity for retransmissions of broadcast messages. In some cases, the base station 105-e may apply CDD in a manner transparent to the UE 115-c (e.g., the base station 105-e may apply CDD without informing the UE 115-c of the CDD). In some other cases, the UE 115-c may identify different CDD values based on signaling from the base station 105-e, or the different CDD values defined by the base station 105-e may be predefined. In still other cases, the UE 115-c may request the application of CDD (e.g., as part of a UE NACK transmission, etc.).

[0122] In some cases, CDD techniques may include transmitting a broadcast message using a first antenna, adding a phase delay (e.g., CDD) to the broadcast message at a second antenna (or adding multiple phase delays to multiple retransmissions of the broadcast message), and retransmitting the broadcast message based on the phase delays. Different phase delays may be associated with different OFDM tones at several antenna ports of the base station 105-e.

[0123] In one example, base station 105-e may apply CDD in the time domain to a broadcast message, which may correspond to a cyclically shifted version of the broadcast message in the frequency domain. In the frequency domain, each tone in each antenna port of base station 105-e may be multiplexed with a different phase rotation. Thus, the equivalent channel at each tone may differ as received by UE 115-c based on the different phase rotations applied (e.g., UE 115-c may receive the broadcast message according to different phase rotations and at different video frequencies, even though the original tone channel without CDD remains the same tone-to-tone).

[0124] The base station 105 - e may transmit a first broadcast message 410 , which may be represented by a signal in the time domain, and corresponding symbols s0 through s10 in the frequency domain, which may be associated with a first frequency configuration. N-1 The base station 105-e may then transmit a second message 415 (e.g., a retransmission of the first message 410), which may be represented by a cyclically shifted signal in the time domain, and a corresponding symbol s0e in the frequency domain that may be associated with the second frequency configuration. j0θ to s N-1 e j(N-1)θ The cyclic shift in the time domain may correspond to a phase shift for each symbol in the frequency domain (e.g., e j(N-1)θ ), which can increase frequency diversity for transmissions from base station 105-e.

[0125] In some cases, the time domain aspects of transmissions 410 and 415 may correspond to different layers (e.g., a multi-layer scenario), where the payloads of broadcast messages 410 and 415 may be cyclically shifted versions of each other. In some multi-layer data scenarios, the base station 105-e may add different precoders for different tones. For example, each input layer may have a different phase shift at a different tone, and the base station 105-e may apply a common precoding matrix. During the precoding process, multiple data streams from the layer mapper may be precoded to distribute the data streams to the antenna ports of the base station 105-e (e.g., using a precoding matrix). In cases where CDD is applied, the base station 105-e may multiply the original precoding matrix by one or more additional matrices that may apply phase shifts, distribute energy between data layers, etc.

[0126] In some other cases, base station 105-e may be part of a cluster of base stations 105 in an SFN. In some cases, base station 105 may participate in coordinated multipoint communication with UE 115-c. In such cases, base station 105 may apply CDD techniques to retransmissions sent to UE 115-c. For example, different cyclic delay values may be applied to different retransmissions at different antenna ports for each base station. In such examples, different antenna ports and / or different cyclic delays may be used at different base stations, or different cyclic delays may be used for multiple antenna ports at a single base station.

[0127] In some other examples, UE 115 may receive retransmissions from multiple different TRPs associated with one or more base stations, and UE 115 may combine received signals from different TRPs or base stations. In such examples, the TRPs may transmit data according to different cyclic delay values, and UE 115 may receive data from the TRPs using one or more directional beams. In some cases, different base stations or different TRPs may apply different delays, such that the cyclic delay value may vary between retransmissions and may also vary between base stations or TRPs. For example, in some networks, a first base station may apply a first set of cyclic diversity delay values (e.g., delay 0, delay 1), a second base station may apply a second set of cyclic diversity delay values that is different from the first set of delay values (e.g., delay 2, delay 3), and a third base station may apply a third set of cyclic diversity delay values that is different from the second set of delay values (e.g., delay 4, delay 5).

[0128] Figure 5 An example of a process flow diagram for supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure is illustrated. In some examples, the process flow diagram 500 can implement aspects of the wireless communication system 100. The process flow diagram 500 can include a base station 105-f and a UE 115-d, which can be as described in reference Figure 1-4Examples of base stations 105 and UEs 115 are described.

[0129] The base station 105-f may transmit a message on a SFN channel in a first frequency configuration using a directional beam at 505. In some cases, the message may be a broadcast message, and the SFN channel may be a multimedia broadcast SFN channel.

[0130] UE 115-d may receive the message on the SFN channel in the first frequency configuration using a directional beam at 510. In some cases, UE 115-d may not receive the message or may incorrectly receive the message from base station 105-f.

[0131] At 515, UE 115-d may transmit a retransmission request to base station 105-f, and base station 105-f may receive the retransmission request from UE 115-d, which may request a retransmission of the message from base station 105-f. For example, UE 115-d may transmit a NACK associated with failed reception of the message. In some cases, the NACK may include a retransmission request. In some other cases, the base station may determine to automatically retransmit the message (e.g., without receiving a retransmission request or NACK from UE 115-d). In such cases, UE 115-d may be configured to receive one or more retransmissions from base station 105-f.

[0132] At 520, the base station may adjust the first frequency configuration to a second frequency configuration. In one example, adjusting the first frequency configuration may include applying a frequency hopping pattern to retransmissions of the message. In such an example, adjusting the first frequency configuration to the second frequency configuration according to the frequency hopping pattern may include a first frequency configuration including a first set of frequency tones allocated for the message, and a second frequency configuration including a second set of frequency tones allocated for retransmissions of the message (e.g., where the first set of frequency tones is different from the second set of frequency tones).

[0133] In another example, adjusting the first frequency configuration may include applying CDD to retransmissions of the message.In some cases, the base station 105-f may receive a request from the UE-115d to apply CDD to the retransmissions.

[0134] In an example where base station 105-f applies CDD, base station 105-f may transmit a message using a first antenna and may apply a first phase delay to at least a portion of the message at a second antenna. Base station 105-f may then transmit a retransmission of the message based on applying the first phase delay.

[0135] At 525, the base station 105-f may transmit an indication of the frequency hopping pattern to the UE 115-d, and the UE 115-d may receive the indication. Additionally or alternatively, the base station 105-f may transmit an indication of CDD to the UE 115-d, and the UE 115-d may receive the indication.

[0136] The base station 105-f may transmit a retransmission of the message in the second frequency configuration over the SFN at 530. In some cases, the base station 105-f may transmit the retransmission of the message upon expiration of an interval after transmitting the message (e.g., the transmission and retransmission may not be contiguous in time).

[0137] In some other examples, base station 105-f may retransmit multiple retransmissions of the message to UE 115-d. For example, the base station may apply a second cyclic diversity delay (e.g., a phase delay) to the second retransmissions, where the second cyclic diversity delay is different from the first cyclic diversity delay used for the first retransmission of the message.

[0138] At 535, UE 115-d may receive a retransmission of the message on the SFN channel in the second frequency configuration. In some cases, UE 115-d may receive the retransmission of the message according to a frequency hopping pattern, wherein at least the second frequency configuration is based at least in part on the frequency hopping pattern.

[0139] In some cases, UE 115-d may receive a retransmission of the message from the first node according to a first CDD, wherein the second frequency configuration is based on the first CDD. UE 115-d may further receive a second retransmission of the message from the first node according to a second CDD different from the first CDD. Furthermore, UE 115-d may receive a retransmission of the message from the second node according to a third CDD different from the first CDD.

[0140] Figure 6 A block diagram 600 is shown of a device 605 that supports frequency diversity techniques for a single frequency network according to aspects of the present disclosure. The device 605 can be an example of aspects of the UE 115 as described herein. The device 605 can include a receiver 610, a communication manager 615, and a transmitter 620. The device 605 can also include a processor. Each of these components can be in communication with each other (e.g., via one or more buses).

[0141] The receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to frequency diversity techniques for single frequency networks, etc.). The information may be passed to other components of the device 605. The receiver 610 may be a reference Figure 9 Examples of aspects of the described transceiver 920. The receiver 610 may utilize a single antenna or a collection of antennas.

[0142] The communication manager 615 can receive a message on a single frequency network channel in a first frequency configuration using directional beams; and receive a retransmission of the message on a single frequency network channel in a second frequency configuration. The communication manager 615 can be an example of aspects of the communication manager 910 described herein.

[0143] The communication manager 615 or its subcomponents may be implemented in hardware, in code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 615 or its subcomponents may be performed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), an FPGA or other programmable logic device designed to perform the functions described in this disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0144] The communication manager 615 or its subcomponents can be physically located at various locations, including being distributed such that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 615 or its subcomponents can be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 615 or its subcomponents can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof.

[0145] The transmitter 620 may transmit signals generated by other components of the device 605. In some examples, the transmitter 620 may be co-located with the receiver 610 in a transceiver module. For example, the transmitter 620 may be a reference Figure 9 Examples of aspects of the described transceiver 920. The transmitter 620 may utilize a single antenna or a collection of antennas.

[0146] Figure 7 A block diagram 700 is shown of a device 705 that supports frequency diversity techniques for a single frequency network according to aspects of the present disclosure. The device 705 can be an example of aspects of the device 605 or UE 115 as described herein. The device 705 can include a receiver 710, a communication manager 715, and a transmitter 730. The device 705 can also include a processor. Each of these components can be in communication with each other (e.g., via one or more buses).

[0147] The receiver 710 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to frequency diversity techniques for single frequency networks, etc.). The information may be passed to other components of the device 705. The receiver 710 may be a reference Figure 9 Examples of aspects of the described transceiver 920. The receiver 710 may utilize a single antenna or a collection of antennas.

[0148] The communication manager 715 can be an example of aspects of the communication manager 615 as described herein. The communication manager 715 can include a first frequency transmitting component 720 and a retransmitting component 725. The communication manager 715 can be an example of aspects of the communication manager 910 as described herein.

[0149] The first frequency receiving component 720 can receive a message on a single frequency network channel using a directional beam in a first frequency configuration. The retransmitting component 725 can receive a retransmission of the message on a single frequency network channel in a second frequency configuration.

[0150] The transmitter 730 may transmit signals generated by other components of the device 705. In some examples, the transmitter 730 may be co-located with the receiver 710 in a transceiver module. For example, the transmitter 730 may be a reference Figure 9 Examples of aspects of the described transceiver 920. The transmitter 730 may utilize a single antenna or a collection of antennas.

[0151] In some examples, the communication manager 715 may be implemented as an integrated circuit or chipset for a mobile device modem, and the receiver 710 and transmitter 720 may be implemented as analog components (e.g., amplifiers, filters, antennas, etc.) coupled to the mobile device modem to enable wireless transmission and reception.

[0152] The communication manager 715 as described herein can be implemented to achieve one or more potential advantages. Various implementations can enable mitigation of interference (e.g., interference caused by one or more broadcast base stations or TRPs) along the received signal space of the device 705 including the communication manager 715. At least one implementation can enable the communication manager 715 to effectively apply various frequency diversity techniques, such as frequency hopping and CDD. At least one implementation can enable the communication manager 715 to effectively reduce noise and interference of broadcast and / or multicast transmissions at the device 705.

[0153] By implementing frequency diversity techniques as described herein, one or more processors of device 705 (e.g., a processor controlling one or more of receiver 710, communication manager 715, and transmitter 720, or in conjunction therewith) can reduce the amount of time required to effectively decode data streams transmitted from multiple serving base stations or TRPs, and can reduce interference and signal noise from broadcast transmissions. Such techniques can improve the overall communication quality within the network.

[0154] Figure 8 A block diagram 800 is shown of a communication manager 805 that supports frequency diversity techniques for a single frequency network in accordance with aspects of the present disclosure. The communication manager 805 can be an example of aspects of the communication manager 615, the communication manager 715, or the communication manager 910 described herein. The communication manager 805 can include a first frequency receiving component 810, a retransmission component 815, a frequency hopping receiving component 820, a CDD receiving component 825, a request module 830, and a HARQ component 835. Each of these modules can communicate directly or indirectly with each other (e.g., via one or more buses).

[0155] The first frequency receiving component 810 can receive messages on a single frequency network channel in a first frequency configuration using a directional beam.

[0156] The HARQ component 835 may transmit a negative acknowledgment associated with the message.

[0157] The retransmitting component 815 can receive a retransmission of the message on the single frequency network channel in the second frequency configuration. In some examples, the retransmitting component 815 can receive the retransmission of the message upon expiration of an interval after receiving the message.

[0158] In some examples, frequency hopping receiving component 820 can receive an indication of a frequency hopping pattern. Frequency hopping receiving component 820 can receive a retransmission of the message according to the frequency hopping pattern, wherein at least the second frequency configuration is based on the frequency hopping pattern.

[0159] The request module 830 may transmit a request to the base station to apply the cyclic diversity delay.

[0160] In some examples, CDD receiving component 825 can receive an indication of a cyclic diversity delay.CDD receiving component 825 can receive a retransmission of the message from the first node according to a first cyclic diversity delay on which at least the second frequency configuration is based.

[0161] In some examples, CDD receiving component 825 can receive a second retransmission of the message from the first node based on a second cyclic diversity delay different from the first cyclic diversity delay. In some examples, CDD receiving component 825 can receive a retransmission of the message from the second node based on a third cyclic diversity delay different from the first cyclic diversity delay.

[0162] Figure 9 A diagram of a system 900 including a device 905 supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure is shown. Device 905 can be an example of, or include components of, device 605, device 705, or UE 115 as described herein. Device 905 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communication manager 910, an I / O controller 915, a transceiver 920, an antenna 925, a memory 930, and a processor 940. These components can be in electronic communication via one or more buses (e.g., bus 945).

[0163] The communications manager 910 may receive a message on a single frequency network channel in a first frequency configuration using a directional beam; and receive a retransmission of the message on a single frequency network channel in a second frequency configuration.

[0164] I / O controller 915 can manage input and output signals for device 905. I / O controller 915 can also manage peripheral devices that are not integrated into device 905. In some cases, I / O controller 915 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 915 can utilize an operating system, such as or another known operating system. In other cases, I / O controller 915 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 915 may be implemented as part of a processor. In some cases, a user may interact with device 905 via I / O controller 915 or via hardware components controlled by I / O controller 915.

[0165] The transceiver 920 can communicate bidirectionally via one or more antennas, wired or wireless links, as described herein. For example, the transceiver 920 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 920 can also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, and demodulate packets received from the antenna.

[0166] In some cases, a wireless device may include a single antenna 925. However, in some cases, the device may have more than one antenna 925, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0167] The memory 930 may include RAM and ROM. The memory 930 may store computer-readable, computer-executable code 935 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 930 may include, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0168] Processor 940 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 940 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into processor 940. Processor 940 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 930) to cause device 905 to perform various functions (e.g., functions or tasks supporting frequency diversity technology for a single frequency network).

[0169] The code 935 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 935 may be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, the code 935 may not be directly executed by the processor 940, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0170] Figure 10 A block diagram 1000 is shown of a device 1005 supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure. The device 1005 can be an example of aspects of a base station 105 as described herein. The device 1005 can include a receiver 1010, a communication manager 1015, and a transmitter 1020. The device 1005 can also include a processor. Each of these components can be in communication with each other (e.g., via one or more buses).

[0171] The receiver 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to frequency diversity technology for single frequency networks, etc.). The information may be passed to other components of the device 1005. The receiver 1010 may be a reference Figure 13 Examples of aspects of the described transceiver 1320. The receiver 1010 may utilize a single antenna or a collection of antennas.

[0172] The communication manager 1015 can transmit a message on a single frequency network channel at a first frequency configuration using a directional beam; adjust the first frequency configuration to a second frequency configuration different from the first frequency configuration; and transmit a retransmission of the message on the single frequency network channel at the second frequency configuration. The communication manager 1015 can be an example of aspects of the communication manager 1310 described herein.

[0173] The communication manager 1015 or its subcomponents may be implemented in hardware, in code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 1015 or its subcomponents may be performed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), an FPGA or other programmable logic device designed to perform the functions described in this disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0174] The communication manager 1015 or its subcomponents can be physically located at various locations, including being distributed such that portions of functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 1015 or its subcomponents can be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 1015 or its subcomponents can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof.

[0175] The transmitter 1020 may transmit signals generated by other components of the device 1005. In some examples, the transmitter 1020 may be co-located with the receiver 1010 in a transceiver module. For example, the transmitter 1020 may be a reference Figure 13 Examples of aspects of the described transceiver 1320. The transmitter 1020 may utilize a single antenna or a collection of antennas.

[0176] Figure 11 A block diagram 1100 is shown of a device 1105 supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure. The device 1105 may be an example of aspects of the device 1005 or base station 105 as described herein. The device 1105 may include a receiver 1110, a communication manager 1115, and a transmitter 1135. The device 1105 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0177] The receiver 1110 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to frequency diversity technology for single frequency networks, etc.). The information may be passed to other components of the device 1105. The receiver 1110 may be a reference Figure 13 Examples of aspects of the described transceiver 1320. The receiver 1110 may utilize a single antenna or a collection of antennas.

[0178] Communications manager 1115 can be an example of aspects of communications manager 1015 as described herein. Communications manager 1115 can include a first frequency transmitting component 1120, a frequency reconfiguration component 1125, and a retransmitting component 1130. Communications manager 1115 can be an example of aspects of communications manager 1310 as described herein.

[0179] The first frequency transmitting component 1120 can transmit a message in a first frequency configuration on a single frequency network channel using a directional beam.

[0180] The frequency reconfiguration component 1125 can adjust the first frequency configuration to a second frequency configuration that is different from the first frequency configuration.

[0181] The retransmitting component 1130 can transmit a retransmission of the message on the SFN channel using the second frequency configuration.

[0182] The transmitter 1135 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1135 may be co-located with the receiver 1110 in a transceiver module. For example, the transmitter 1135 may be a reference Figure 13 Examples of various aspects of the described transceiver 1320. The transmitter 1135 may utilize a single antenna or a collection of antennas.

[0183] Figure 12 A block diagram 1200 is shown of a communication manager 1205 supporting frequency diversity techniques for a single frequency network in accordance with aspects of the present disclosure. The communication manager 1205 can be an example of aspects of the communication manager 1015, the communication manager 1115, or the communication manager 1310 described herein. The communication manager 1205 can include a first frequency transmission component 1210, a frequency reconfiguration component 1215, a retransmission component 1220, a frequency hopping component 1225, a CDD transmission component 1230, a HARQ component 1235, and a broadcast component 1240. Each of these modules can communicate directly or indirectly with each other (e.g., via one or more buses).

[0184] The first frequency transmitting component 1210 can transmit a message in a first frequency configuration on a single frequency network channel using a directional beam.

[0185] The HARQ component 1235 can receive a negative acknowledgment associated with the message, wherein transmitting a retransmission of the message is based on receiving the negative acknowledgment.

[0186] The frequency reconfiguration component 1215 can adjust the first frequency configuration to a second frequency configuration that is different from the first frequency configuration.

[0187] In some examples, frequency hopping component 1225 can transmit an indication of a frequency hopping pattern. Frequency hopping component 1225 can apply the frequency hopping pattern to retransmissions of the message.

[0188] In some cases, the first frequency configuration includes a first set of tones allocated for the message, and the second frequency configuration includes a second set of tones, different from the first set of tones, allocated for retransmissions of the message.

[0189] In some examples, CDD transmitting component 1230 may transmit an indication of a cyclic diversity delay. In some examples, CDD transmitting component 1230 may receive a request from the UE to apply the cyclic diversity delay. CDD transmitting component 1230 may apply the cyclic diversity delay to retransmissions of the message. In some examples, CDD transmitting component 1230 may transmit the message using a first antenna. In some examples, CDD transmitting component 1230 may apply a first phase delay to at least a portion of the message at a second antenna.

[0190] In some examples, CDD transmitting component 1230 can transmit a retransmission of the message based on a first phase delay. In some examples, CDD transmitting component 1230 can transmit a second retransmission of the message based on a second phase delay that is different than the first phase delay.

[0191] The retransmitting component 1220 can transmit a retransmission of the message on the SFN channel using the second frequency configuration.

[0192] In some examples, retransmission component 1220 can transmit a retransmission of the message upon expiration of an interval after transmitting the message. In some cases, the retransmission is transmitted automatically.

[0193] Broadcast component 1240 can indicate the message as a broadcast message.In some cases, the SFN channel comprises a multimedia broadcast SFN channel.

[0194] Figure 13A diagram of a system 1300 including a device 1305 supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure is shown. Device 1305 may be an example of, or include components of, device 1005, device 1105, or base station 105 as described herein. Device 1305 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communications manager 1310, a network communications manager 1315, a transceiver 1320, an antenna 1325, a memory 1330, a processor 1340, and an inter-station communications manager 1345. These components may be in electronic communication via one or more buses (e.g., bus 1350).

[0195] The communication manager 1310 may transmit a message on a single frequency network channel in a first frequency configuration using a directional beam; adjust the first frequency configuration to a second frequency configuration different from the first frequency configuration; and transmit a retransmission of the message on the single frequency network channel in the second frequency configuration.

[0196] The network communications manager 1315 may manage communications with the core network (eg, via one or more wired backhaul links). For example, the network communications manager 1315 may manage the delivery of data communications for client devices, such as one or more UEs 115.

[0197] The transceiver 1320 can communicate bidirectionally via one or more antennas, wired or wireless links, as described herein. For example, the transceiver 1320 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 1320 can also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, and demodulate packets received from the antenna.

[0198] In some cases, a wireless device may include a single antenna 1325. However, in some cases, the device may have more than one antenna 1325, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0199] Memory 1330 may include RAM, ROM, or a combination thereof. Memory 1330 may store computer-readable code 1335 including instructions that, when executed by a processor (e.g., processor 1340), cause the device to perform the various functions described herein. In some cases, memory 1330 may include, among other things, a BIOS that controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0200] Processor 1340 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1340 may be configured to operate a memory array using a memory controller. In some cases, the memory controller may be integrated into processor 1340. Processor 1340 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1330) to cause device 1305 to perform various functions (e.g., functions or tasks supporting frequency diversity technology for a single frequency network).

[0201] The inter-site communication manager 1345 can manage communications with other base stations 105 and can include a controller or scheduler for controlling communications with the UE 115 in coordination with the other base stations 105. For example, the inter-site communication manager 1345 can coordinate the scheduling of transmissions to the UE 115 for various interference mitigation techniques, such as beamforming or joint transmission. In some examples, the inter-site communication manager 1345 can provide an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between the base stations 105.

[0202] The code 1335 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1335 may be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, the code 1335 may not be directly executed by the processor 1340, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0203] Figure 14 A flow chart illustrating a method 1400 for supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure is shown. The operations of the method 1400 may be implemented by the base station 105 or components thereof as described herein. For example, the operations of the method 1400 may be implemented by the base station 105 or components thereof as described herein. Figures 10 to 13 In some examples, a base station may execute an instruction set to control functional elements of the base station to perform the functions described herein. Additionally or alternatively, a base station may use dedicated hardware to perform various aspects of the functions described herein.

[0204] At 1405, the base station may transmit a message on a single frequency network channel using a directional beam in a first frequency configuration. The operations of 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be performed as described with reference to Figures 10 to 13 The first frequency transfer component described is performed.

[0205] At 1410, the base station may adjust the first frequency configuration to a second frequency configuration that is different from the first frequency configuration. The operations of 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be as described with reference to Figures 10 to 13 The frequency reconfiguration component described is used to perform the above operation.

[0206] At 1415, the base station may transmit a retransmission of the message on the single frequency network channel in the second frequency configuration. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be performed as described with reference to Figures 10 to 13 The retransmission component described is performed.

[0207] Figure 15 A flow chart illustrating a method 1500 for supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure is shown. The operations of the method 1500 may be implemented by the base station 105 or components thereof as described herein. For example, the operations of the method 1500 may be implemented by the base station 105 or components thereof as described herein. Figures 10 to 13 In some examples, a base station may execute an instruction set to control functional elements of the base station to perform the functions described herein. Additionally or alternatively, a base station may use dedicated hardware to perform various aspects of the functions described herein.

[0208] At 1505, the base station may transmit a message on a single frequency network channel using a directional beam in a first frequency configuration. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be performed as described with reference to Figures 10 to 13 The first frequency transfer component described is performed.

[0209] At 1510, the base station may adjust the first frequency configuration to a second frequency configuration that is different from the first frequency configuration. The operations of 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be as described with reference to Figures 10 to 13 The frequency reconfiguration component described is used to perform the above operation.

[0210] At 1515, the base station may apply a frequency hopping pattern to retransmissions of the message. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be performed as described with reference to Figures 10 to 13 The described frequency hopping components are implemented.

[0211] At 1520, the base station may transmit a retransmission of the message on a single frequency network channel in a second frequency configuration. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be as described with reference to Figures 10 to 13 The retransmission component described is performed.

[0212] Figure 16 A flow chart illustrating a method 1600 for supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 1600 may be implemented by a base station 105 or components thereof as described herein. Figures 10 to 13 In some examples, a base station may execute an instruction set to control functional elements of the base station to perform the functions described herein. Additionally or alternatively, a base station may use dedicated hardware to perform various aspects of the functions described herein.

[0213] At 1605, the base station may transmit a message on a single frequency network channel using a directional beam in a first frequency configuration. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed as described with reference to Figures 10 to 13 The first frequency transfer component described is performed.

[0214] At 1610, the base station may adjust the first frequency configuration to a second frequency configuration that is different from the first frequency configuration. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be as described with reference to Figures 10 to 13 The frequency reconfiguration component described is used to perform the above operation.

[0215] At 1615, the base station may apply a cyclic diversity delay to the retransmission of the message. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed as described with reference to Figures 10 to 13 The CDD delivery component described is executed.

[0216] At 1620, the base station may transmit a retransmission of the message on a single frequency network channel in a second frequency configuration. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be as described with reference to Figures 10 to 13 The retransmission component described is performed.

[0217] Figure 17 1700 is a flowchart illustrating a method 1700 for supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure. The operations of the method 1700 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1700 may be implemented by the UE 115 or components thereof as described herein. Figures 6 to 9 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0218] At 1705, the UE may receive a message on a single frequency network channel using a directional beam in a first frequency configuration. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be as described with reference to Figures 6 to 9 The described first frequency receiving component is performed.

[0219] At 1710, the UE may receive a retransmission of the message on a single frequency network channel in a second frequency configuration. The operations of 1710 may be performed according to the methods described herein. In some examples, aspects of the operations of 1710 may be as described with reference to Figures 6 to 9 The retransmission component described is performed.

[0220] Figure 18 A flow chart illustrating a method 1800 for supporting frequency diversity techniques for a single frequency network according to aspects of the present disclosure is shown. The operations of the method 1800 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1800 may be implemented by a UE 115 or components thereof as described herein. Figures 6 to 9 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0221] At 1805, the UE may receive a message on a single frequency network channel using a directional beam in a first frequency configuration. The operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be as described with reference to Figures 6 to 9 The described first frequency receiving component is performed.

[0222] At 1810, the UE may receive a retransmission of the message from the first node according to a first cyclic diversity delay, wherein at least the second frequency configuration is based on the first cyclic diversity delay. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be as described with reference to Figures 6 to 9 The described CDD receives components to execute.

[0223] At 1815, the UE may receive a second retransmission of the message from the first node based on a second cyclic diversity delay different from the first cyclic diversity delay. The operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be as described with reference to Figures 6 to 9 The described CDD receives components to execute.

[0224] At 1820, the UE may receive a retransmission of the message from the second node according to a third cyclic diversity delay that is different from the first cyclic diversity delay. The operations of 1820 may be performed according to the methods described herein. In some examples, aspects of the operations of 1820 may be as described with reference to Figures 6 to 9 The described CDD receives components to execute.

[0225] At 1825, the UE may receive a retransmission of the message on a single frequency network channel in a second frequency configuration. The operations of 1825 may be performed according to the methods described herein. In some examples, aspects of the operations of 1825 may be as described with reference to Figures 6 to 9 The retransmission component described is performed.

[0226] The following provides an overview of various aspects of the disclosure:

[0227] Aspect 1: A method for wireless communication at a base station, comprising: transmitting a message on a single frequency network channel at a first frequency configuration using a directional beam; adjusting the first frequency configuration to a second frequency configuration different from the first frequency configuration; and transmitting a retransmission of the message on the single frequency network channel at the second frequency configuration.

[0228] Aspect 2: The method of aspect 1, wherein adjusting the first frequency configuration comprises: applying a frequency hopping pattern to retransmission of the message

[0229] Aspect 3: The method of aspect 2 further comprises: transmitting an indication of the frequency hopping mode.

[0230] Aspect 4: The method of any of Aspects 2 to 3, wherein the first frequency configuration comprises a first set of frequency tones allocated for the message, and the second frequency configuration comprises a second set of frequency tones different from the first set of frequency tones allocated for retransmission of the message.

[0231] Aspect 5: The method according to any one of aspects 1 to 4, wherein adjusting the first frequency configuration comprises: applying a cyclic diversity delay to retransmissions of the message

[0232] Aspect 6: The method of aspect 5, further comprising: transmitting an indication of the cyclic diversity delay.

[0233] Aspect 7: The method according to any one of aspects 5 to 6, further comprising: receiving a request to apply a cyclic diversity delay from a UE.

[0234] Aspect 8: A method as in any one of Aspects 5 to 7, wherein applying a cyclic diversity delay to a retransmission of a message comprises: transmitting the message using a first antenna; applying a first phase delay to at least a portion of the message at a second antenna; and transmitting the retransmission of the message based at least in part on the first phase delay.

[0235] Aspect 9: The method of aspect 8, further comprising: transmitting a second retransmission of the message based at least in part on a second phase delay different from the first phase delay.

[0236] Aspect 10: The method of any one of aspects 1 to 9, further comprising: receiving a negative acknowledgement associated with the message, wherein the retransmission of the message is based at least in part on receiving the negative acknowledgement.

[0237] Aspect 11: The method of aspect 10, wherein the negative acknowledgement includes a retransmission request associated with the message.

[0238] Aspect 12: The method of any one of aspects 1 to 9, wherein the retransmission is automatically transmitted.

[0239] Aspect 13: The method of aspect 12 further comprises: upon expiration of a gap after transmitting the message, retransmitting the message

[0240] Aspect 14: The method of any one of Aspects 1 to 13, wherein the message comprises a broadcast message.

[0241] Aspect 15: The method according to any one of aspects 1 to 14, wherein the single frequency network channel comprises a multimedia broadcast single frequency network channel.

[0242] Aspect 16: A method for wireless communication at a UE, comprising: receiving a message on a single frequency network channel in a first frequency configuration using a directional beam; and receiving a retransmission of the message on the single frequency network channel in a second frequency configuration.

[0243] Aspect 17: The method of Aspect 16, further comprising: receiving a retransmission of the message according to a frequency hopping pattern, wherein at least the second frequency configuration is based at least in part on the frequency hopping pattern.

[0244] Aspect 18: The method of Aspect 17 further comprises: receiving an indication of a frequency hopping pattern.

[0245] Aspect 19: The method of any one of aspects 16 to 18, further comprising: receiving a retransmission of the message from the first node according to a first cyclic diversity delay, wherein at least the second frequency configuration is based at least in part on the first cyclic diversity delay.

[0246] Aspect 20: The method of aspect 19, further comprising: receiving an indication of the first cyclic diversity delay.

[0247] Aspect 21: The method of any one of Aspects 19 to 20, further comprising: receiving a second retransmission of the message from the first node based at least in part on a second cyclic diversity delay different from the first cyclic diversity delay.

[0248] Aspect 22: The method of any one of aspects 19 to 21, further comprising: receiving a retransmission of the message from the second node according to a third cyclic diversity delay different from the first cyclic diversity delay.

[0249] Aspect 23: The method according to any one of aspects 19 to 22, further comprising: transmitting a request to apply a first cyclic diversity delay to the base station.

[0250] Aspect 24: The method of any one of Aspects 16 to 23, further comprising: receiving a retransmission of the message upon expiration of a gap after receiving the message.

[0251] Aspect 25: The method of any one of aspects 16 to 24, further comprising: transmitting a negative acknowledgement associated with the message.

[0252] Aspect 26: The method of Aspect 25, wherein the negative acknowledgement includes a retransmission request associated with the message.

[0253] Aspect 27: An apparatus for performing wireless communication at a base station, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method as described in any one of Aspects 1 to 15.

[0254] Aspect 28: An apparatus for wireless communication at a base station, comprising at least one means for performing the method of any one of Aspects 1 to 15.

[0255] Aspect 29: A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to perform the method of any one of aspects 1 to 15.

[0256] Aspect 30: An apparatus for wireless communication at a UE, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of aspects 16 to 24.

[0257] Aspect 31: An apparatus for wireless communication at a UE, comprising at least one means for performing the method of any one of aspects 16 to 24.

[0258] Aspect 32: A non-transitory computer-readable medium storing code for wireless communication at a UE, the code comprising instructions executable by a processor to perform the method of any one of aspects 16 to 24.

[0259] Aspect 33: An apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of aspects 25 to 26.

[0260] Aspect 34: An apparatus comprising at least one means for performing the method of any one of aspects 25 to 26.

[0261] Aspect 35: A non-transitory computer-readable medium storing code, the code comprising instructions executable by a processor to perform the method of any one of Aspects 25 to 26.

[0262] It should be noted that the methods described herein describe possible implementations, and that the operations and steps may be rearranged or otherwise modified and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0263] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used throughout much of the description, the techniques described herein may also be applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described may be applicable to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0264] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0265] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a digital signal processor (DSP) and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0266] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted by a computer-readable medium as one or more instructions or code. Other examples and implementations fall within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features that implement the functions may also be physically located in various locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0267] Computer-readable media include both non-transient computer storage media and communication media, including any media that facilitates the transfer of a computer program from one place to another. Non-transient storage media can be any available medium that can be accessed by a general or special-purpose computer. As an example and not limitation, non-transient computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, magnetic disk storage or other magnetic storage device, or any other non-transient medium that can be used to carry or store the desired program code means in the form of instructions or data structures and can be accessed by a general or special-purpose computer, or a general or special-purpose processor. Similarly, any connection is also properly referred to as a computer-readable medium. For example, if software is transmitted from a website, server or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of computer-readable media. Disk and disc, as used herein, include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations herein are also included within the scope of computer-readable media.

[0268] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items followed by a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Likewise, as used herein, the phrase "based on" should not be read as referencing a closed set of conditions. For example, an example step described as "based on condition A" could be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be read in the same manner as the phrase "based at least in part on."

[0269] In the accompanying drawings, similar components or features may have the same reference number. In addition, components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between the similar components. If only the first reference number is used in the specification, the description applies to any of the similar components having the same first reference number, regardless of the second reference number or other subsequent reference numbers.

[0270] The description set forth herein in conjunction with the accompanying drawings describes example configurations and does not represent all examples that can be implemented or fall within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration" and does not mean "better than" or "better than other examples." This detailed description includes specific details to provide an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0271] The description herein is provided to enable one of ordinary skill in the art to make or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a network device, comprising: transmitting a broadcast message on a single frequency network channel in a first frequency configuration using a directional beam; transmitting an indication of a second frequency configuration for at least one retransmission of the broadcast message, wherein the second frequency configuration is different from the first frequency configuration; adjusting the first frequency configuration to the second frequency configuration; as well as The at least one retransmission of the broadcast message is transmitted on the single frequency network channel in the second frequency configuration.

2. The method of claim 1 , wherein adjusting the first frequency configuration comprises: A frequency hopping pattern is applied to the at least one retransmission of the broadcast message.

3. The method of claim 2, further comprising: An indication of the frequency hopping pattern is transmitted.

4. The method of claim 2, wherein the first frequency configuration comprises a first frequency tuning set allocated for the broadcast message, and the second frequency configuration comprises a second frequency tuning set different from the first frequency tuning set allocated for the at least one retransmission of the broadcast message.

5. The method of claim 1 , wherein adjusting the first frequency configuration comprises: A cyclic diversity delay is applied to the at least one retransmission of the broadcast message.

6. The method of claim 5, further comprising: An indication of the cyclic diversity delay is transmitted.

7. The method of claim 5, further comprising: A request to apply the cyclic diversity delay is received from a user equipment (UE).

8. The method of claim 5, wherein applying the cyclic diversity delay to the at least one retransmission of the broadcast message comprises: transmitting the broadcast message using a first antenna; applying a first phase delay to at least a portion of the broadcast message at a second antenna; as well as The at least one retransmission of the broadcast message is transmitted based at least in part on the first phase delay.

9. The method of claim 8, further comprising: A second retransmission of the broadcast message is transmitted based at least in part on a second phase delay different than the first phase delay.

10. The method of claim 1, further comprising: A negative acknowledgment associated with the broadcast message is received, wherein transmitting the at least one retransmission of the broadcast message is based at least in part on receiving the negative acknowledgment.

11. The method of claim 10, wherein the negative acknowledgement comprises a retransmission request associated with the broadcast message.

12. The method of claim 1, wherein the at least one retransmission is transmitted automatically.

13. The method of claim 12, further comprising: Upon expiration of a gap after transmitting the broadcast message, the at least one retransmission of the broadcast message is transmitted.

14. The method of claim 1, wherein the single frequency network channel comprises a multimedia broadcast single frequency network channel.

15. A method for wireless communication at a user equipment (UE), comprising: receiving a broadcast message on a single frequency network channel in a first frequency configuration using a directional beam; receiving a message having an indication of a second frequency configuration for at least one retransmission of the broadcast message; as well as At least one retransmission of the broadcast message is received on the single frequency network channel in the second frequency configuration.

16. The method of claim 15, further comprising: The at least one retransmission of the broadcast message is received according to a frequency hopping pattern, wherein at least the second frequency configuration is based at least in part on the frequency hopping pattern.

17. The method of claim 16, further comprising: An indication of the frequency hopping pattern is received.

18. The method of claim 15, further comprising: The at least one retransmission of the broadcast message is received from a first node according to a first cyclic diversity delay, wherein at least the second frequency configuration is based at least in part on the first cyclic diversity delay.

19. The method of claim 18, further comprising: An indication of the first cyclic diversity delay is received.

20. The method of claim 18, further comprising: A second retransmission of the broadcast message is received from the first node based at least in part on a second cyclic diversity delay different than the first cyclic diversity delay.

21. The method of claim 18, further comprising: The at least one retransmission of the broadcast message is received from a second node according to a third cyclic diversity delay different from the first cyclic diversity delay.

22. The method of claim 18, further comprising: A request to apply the first cyclic diversity delay is transmitted to a network device.

23. The method of claim 15, further comprising: A negative acknowledgment associated with the broadcast message is transmitted.

24. The method of claim 23, wherein the negative acknowledgement comprises a retransmission request associated with the broadcast message.

25. The method of claim 15, further comprising: Upon expiration of a gap after receiving the broadcast message, the at least one retransmission of the broadcast message is received.

26. An apparatus for wireless communication at a network device, comprising: processor; a memory coupled to the processor; as well as instructions stored in the memory and executed by the processor, the instructions causing the apparatus to: transmitting a broadcast message on a single frequency network channel in a first frequency configuration using a directional beam; transmitting an indication of a second frequency configuration for at least one retransmission of the broadcast message, wherein the second frequency configuration is different from the first frequency configuration; adjusting the first frequency configuration to be consistent with the second frequency configuration; as well as The at least one retransmission of the broadcast message is transmitted on the single frequency network channel in the second frequency configuration.

27. An apparatus for wireless communication at a network device, comprising: processor; a memory coupled to the processor; as well as Instructions stored in the memory and executed by the processor, the instructions causing the apparatus to perform the method according to any one of claims 2 to 14.

28. An apparatus for wireless communication at a user equipment (UE), comprising: processor; a memory coupled to the processor; as well as Instructions stored in the memory and executed by the processor, the instructions causing the apparatus to: receive a broadcast message on a single frequency network channel in a first frequency configuration using a directional beam; receiving a message having an indication of a second frequency configuration for at least one retransmission of the broadcast message; as well as At least one retransmission of the broadcast message is received on the single frequency network channel in the second frequency configuration.

29. An apparatus for wireless communication at a user equipment (UE), comprising: processor; a memory coupled to the processor; as well as Instructions stored in the memory and executed by the processor, the instructions causing the apparatus to perform the method of any one of claims 16-25.

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