Patent Description:
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, etc. These systems may employ multiple-access technologies capable of supporting communications with multiple users by sharing available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, LTE Advanced (LTE-A) systems, code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

In some examples, a wireless multiple-access communication system may include a number of base stations (BSs) that each can simultaneously support communication for multiple communication devices, otherwise known as user equipment (UEs). In LTE or LTE-A network, a set of one or more gNBs may define an e NodeB (eNB). In other examples (e.g., in a next generation, new radio (NR), or <NUM> network), a wireless multiple access communication system may include a number of distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmission reception points (TRPs), etc.) in communication with a number of central units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), where a set of one or more distributed units, in communication with a central unit, may define an access node (e.g., a NR BS, a NR NB, a network node, a <NUM> NB, a next generation NB (gNB), etc.). A gNB or DU may communicate with a set of UEs on downlink channels (e.g., for transmissions from a base station or to a UE) and uplink channels (e.g., for transmissions from a UE to a gNB or DU).

NR (e.g., <NUM> radio access) is an example of an emerging telecommunication standard.

Such improvements may help enable "peer to peer" communication between a variety of devices, also referred to as device to device (D2D) communications. Examples of D2D communications include vehicle to everything (V2X) communications, where a vehicle may communicate with another vehicle (V2V) or a different device, such as a base station, traffic control system, or the like (all of which may help enable autonomous driving).

<NPL> provides details on physical layer structure for SL V2X.

The invention is described herein with reference to the appended claims.

Certain aspects of the present disclosure provide a method for wireless communications by a peer device in accordance with claim <NUM>.

Certain aspects of the present disclosure provide a peer wireless communications device according to claim <NUM>.

Certain aspects of the present disclosure provide a peer wireless communication device according to claim <NUM>.

Certain aspects of the present disclosure provide a method for wireless communications by a peer device according to claim <NUM>.

As noted above, examples of peer-to-peer (also referred to as device-to-device or D2D) communications include vehicle to everything (V2X) communications where a vehicle may communicate with another vehicle (V2V) or a different device, such as a base station, traffic control system, or the like.

One challenge in V2X systems is to support different types of traffic. The different types of traffic require different types of control information. As a result, a single control channel format is inefficient as the payload may be too large for some types of traffic, resulting in a waste of resources. In addition a single format to schedule different types of traffic may result in a large number of blind decoding operations.

Aspects of the present disclosure may help address this challenge by sending control information for scheduling peer-to-peer (e.g. V2X) traffic in multiple stages.

The techniques presented herein may be applied in various scenarios, such as NR (new radio access technology or <NUM> technology). NR may support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g. <NUM> beyond), millimeter wave (mmW) targeting high carrier frequency (e.g. <NUM> or beyond), massive machine type communications (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra-reliable low-latency communications (URLLC).

In certain systems, (e.g., 3GPP Release-<NUM> long term evolution (LTE) networks), enhanced machine type communications (eMTC) are supported, targeting low cost devices, often at the cost of lower throughput. eMTC may involve half-duplex (HD) operation in which uplink transmissions and downlink transmissions can both be performed-but not simultaneously. Some eMTC devices (e.g., eMTC UEs) may look at (e.g., be configured with or monitor) no more than around <NUM> or six resource blocks (RBs) of bandwidth at any given time. eMTC UEs may be configured to receive no more than around <NUM> bits per subframe. For example, these eMTC UEs may support a max throughput of around <NUM> Kbits per second. This throughput may be sufficient for certain eMTC use cases, such as certain activity tracking, smart meter tracking, and/or updates, etc., which may consist of infrequent transmissions of small amounts of data; however, greater throughput for eMTC devices may be desirable for other cases, such as certain Internet-of-Things (IoT) use cases, wearables such as smart watches, etc..

The following description provides examples, and is not limiting of the scope, set forth in the claims. Changes may be made in the function and arrangement of elements discussed.

An OFDMA network may implement a radio technology such as NR (e.g. <NUM> RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UNM), IEEE <NUM> (Wi-Fi), IEEE <NUM> (WiMAX), IEEE <NUM>, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS).

<FIG> illustrates an example wireless network <NUM> in which aspects of the present disclosure may be performed. For example, techniques presented herein may help transmitting control information for scheduling peer-to-peer traffic in multiple stages. For example, base stations <NUM> and UEs <NUM> (e.g., V2V UEs, such as UE120v-<NUM>, 120v-<NUM>, and UE 120v-<NUM>) may perform operations <NUM> and/or <NUM> to send control information in multiple stages (and/or process the same).

The wireless network <NUM> may be, for example, a new radio (NR) or <NUM> network. A UE <NUM> may be configured for enhanced machine type communications (eMTC). The UE <NUM> may be considered a low cost device, low cost UE, eMTC device, and/or eMTC UE. The UE <NUM> can be configured to support higher bandwidth and/or data rates (e.g., higher than <NUM>). The UE <NUM> may be configured with a plurality of narrowband regions (e.g., <NUM> resource blocks (RBs) or <NUM> RBs). The UE <NUM> may receive a resource allocation, from a gNB <NUM>, allocating frequency hopped resources within a system bandwidth for the UE <NUM> to monitor and/or transmit on. The resource allocation can indicate non-contiguous narrowband frequency resources for uplink transmission in at least one subframe. The resource allocation may indicate frequency resources are not contained within a bandwidth capability of the UE to monitor for downlink transmission. The UE <NUM> may determine, based on the resource allocation, different narrowband than the resources indicated in the resource allocation from the gNB <NUM> for uplink transmission or for monitoring. The resource allocation indication (e.g., such as that included in the downlink control information (DCI)) may include a set of allocated subframes, frequency hopping related parameters, and an explicit resource allocation on the first subframe of the allocated subframes. The frequency hopped resource allocation on subsequent subframes are obtained by applying the frequency hopping procedure based on the frequency hopping related parameters (which may also be partly included in the DCI and configured partly through radio resource control (RRC) signaling) starting from the resources allocated on the first subframe of the allocated subframes.

As illustrated in <FIG>, the wireless network <NUM> may include a number of gNBs <NUM> and other network entities. A gNB may be a station that communicates with UEs. Each gNB <NUM> may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to a coverage area of a Node B and/or a NB subsystem serving this coverage area, depending on the context in which the term is used. In NR systems, the term "cell" and NB, next generation NB (gNB), <NUM> NB, access point (AP), BS, NR BS, or transmission reception point (TRP) may be interchangeable. In some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile gNB. In some examples, the gNBs may be interconnected to one another and/or to one or more other gNBs or network nodes (not shown) in the wireless network <NUM> through various types of backhaul interfaces such as a direct physical connection, a virtual network, or the like using any suitable transport network.

A RAT may also be referred to as a radio technology, an air interface, etc. A frequency may also be referred to as a carrier, a frequency channel, a tone, a subband, a subcarrier, etc. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs.

A gNB may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cell. A gNB for a macro cell may be referred to as a macro gNB. A gNB for a pico cell may be referred to as a pico gNB. A gNB for a femto cell may be referred to as a femto gNB or a home gNB. In the example shown in <FIG>, the gNBs 110a, 110b and 110c may be macro gNBs for the macro cells 102a, 102b and 102c, respectively. The gNB 110x may be a pico gNB for a pico cell 102x. The gNBs 110y and 110z may be femto gNB for the femto cells 102y and 102z, respectively. A gNB may support one or multiple (e.g., three) cells.

A relay station is a station that receives a transmission of data and/or other information from an upstream station (e.g., a gNB or a UE) and sends a transmission of the data and/or other information to a downstream station (e.g., a UE or a gNB). In the example shown in <FIG>, a relay station 110r may communicate with the gNB 110a and a UE 120r in order to facilitate communication between the gNB 110a and the UE 120r. A relay station may also be referred to as a relay gNB, a relay, etc..

The wireless network <NUM> may be a heterogeneous network that includes gNBs of different types, e.g., macro gNB, pico gNB, femto gNB, relays, etc. These different types of gNBs may have different transmit power levels, different coverage areas, and different impact on interference in the wireless network <NUM>. For example, a macro gNB may have a high transmit power level (e.g., <NUM> Watts) whereas pico gNB, femto gNB, and relays may have a lower transmit power level (e.g., <NUM> Watt).

For synchronous operation, the gNBs may have similar frame timing, and transmissions from different gNBs may be approximately aligned in time. For asynchronous operation, the gNBs may have different frame timing, and transmissions from different gNBs may not be aligned in time.

A network controller <NUM> may couple to a set of gNBs and provide coordination and control for these gNBs. The network controller <NUM> may communicate with the gNBs <NUM> via a backhaul. The gNBs <NUM> may also communicate with one another, for example, directly or indirectly via wireless or wireline backhaul.

A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a Customer Premises Equipment (CPE), a cellular phone, a smart phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or medical equipment, a biometric sensor/device, a wearable device such as a smart watch, smart clothing, smart glasses, a smart wrist band, smart jewelry (e.g., a smart ring, a smart bracelet, etc.), an entertainment device (e.g., a music device, a video device, a satellite radio, etc.), a vehicular component or sensor, a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium. Some UEs may be considered evolved or machine-type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., that may communicate with a gNB, another device (e.g., remote device), or some other entity. Some UEs may be considered Internet-of-Things (IoT) devices or narrowband IoT (NB-IoT) devices.

In <FIG>, a solid line with double arrows indicates desired transmissions between a UE and a serving gNB, which is a gNB designated to serve the UE on the downlink and/or uplink. A finely dashed line with double arrows indicates interfering transmissions between a UE and a gNB.

For example, the spacing of the subcarriers may be <NUM> and the minimum resource allocation (e.g., an RB) may be <NUM> subcarriers (or <NUM>). Consequently, the nominal FFT size may be equal to <NUM>, <NUM>, <NUM>, <NUM> or <NUM> for system bandwidth of <NUM>, <NUM>, <NUM>, <NUM> or <NUM> megahertz (MHz), respectively. For example, a subband may cover <NUM> (i.e., <NUM> resource blocks), and there may be <NUM>, <NUM>, <NUM>, <NUM> or <NUM> subbands for system bandwidth of <NUM>, <NUM>, <NUM>, <NUM> or <NUM>, respectively.

A single component carrier bandwidth of <NUM> may be supported. NR resource blocks may span <NUM> sub-carriers with a sub-carrier bandwidth of <NUM> over a <NUM> duration. Each radio frame may consist of two half frames, each half frame consisting of <NUM> subframes, with a length of <NUM>. Consequently, each subframe may have a length of <NUM>. Each subframe may indicate a link direction (i.e., DL or UL) for data transmission and the link direction for each subframe may be dynamically switched. Each subframe may include DL/UL data as well as DL/UL control data. UL and DL subframes for NR may be as described in more detail below with respect to <FIG> and <FIG>.

slots) depending on the tone-spacing (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

In some examples, access to the air interface may be scheduled, wherein a scheduling entity (e.g., a gNB) allocates resources for communication among some or all devices and equipment within its service area or cell. gNBs are not the only entities that may function as a scheduling entity.

<FIG> illustrates example components of the gNB <NUM> and UE <NUM> illustrated in <FIG>, which may be used to implement aspects of the present disclosure for frequency hopping for large bandwidth allocations. For example, antennas <NUM>, Tx/Rx <NUM>, processors <NUM>, <NUM>, <NUM>, and/or controller/processor <NUM> of the UE <NUM> and/or antennas <NUM>, processors <NUM>, <NUM>, <NUM>, and/or controller/processor <NUM> of the gNB <NUM> may be used to perform the operations described herein and illustrated with reference to <FIG> and <FIG>.

<FIG> shows a block diagram of a design of a gNB <NUM> and a UE <NUM>, which may be one of the gNBs and one of the UEs in <FIG>. For a restricted association scenario, the gNB <NUM> may be the macro gNB 110c in <FIG>, and the UE <NUM> may be the UE 120y. The gNB <NUM> may also be gNB of some other type. The gNB <NUM> may be equipped with antennas 234a through 234t, and the UE <NUM> may be equipped with antennas 252a through 252r.

At the gNB <NUM>, a transmit processor <NUM> may receive data from a data source <NUM> and control information from a controller/processor <NUM>. The control information may be for the Physical Broadcast Channel (PBCH), Physical Control Format Indicator Channel (PCFICH), Physical Hybrid ARQ Indicator Channel (PHICH), Physical Downlink Control Channel (PDCCH), etc. The data may be for the Physical Downlink Shared Channel (PDSCH), etc. The processor <NUM> may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The processor <NUM> may also generate reference symbols, e.g., for the PSS, SSS, and cell-specific reference signal (CRS). A transmit (TX) multiple-input multiple-output (MIMO) processor <NUM> may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) 232a through 232t. Downlink signals from modulators 232a through 232t may be transmitted via the antennas 234a through 234t, respectively.

At the UE <NUM>, the antennas 252a through 252r may receive the downlink signals from the gNB <NUM> and may provide received signals to the demodulators (DEMODs) 254a through 254r, respectively. A MIMO detector <NUM> may obtain received symbols from all the demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols.

The symbols from the transmit processor <NUM> may be precoded by a TX MIMO processor <NUM> if applicable, further processed by the demodulators 254a through 254r (e.g., for SC-FDM, etc.), and transmitted to the gNB <NUM>. At the gNB <NUM>, the uplink signals from the UE <NUM> may be received by the antennas <NUM>, processed by the modulators <NUM>, detected by a MIMO detector <NUM> if applicable, and further processed by a receive processor <NUM> to obtain decoded data and control information sent by the UE <NUM>.

The controllers/processors <NUM> and <NUM> may direct the operation at the gNB <NUM> and the UE <NUM>, respectively. The processor <NUM> and/or other processors and modules at the gNB <NUM> may perform or direct, e.g., the execution of various processes for the techniques described herein. The processor <NUM> and/or other processors and modules at the UE <NUM> may also perform or direct, e.g., the execution of the functional blocks illustrated in <FIG> and <FIG>, and/or other processes for the techniques described herein.

As noted above, LTE vehicle-to-everything (LTE-V2X) has been developed as a technology to address basic vehicular wireless communications to enhance road safety and the driving experience. In other systems, new radio vehicle-to-everything (NR-V2X) has been developed as an additional technology that covers more advanced communication use cases to further enhance road safety and driving experience. Non-limiting embodiments for frequencies covered may be, for example, <NUM> to <NUM>. As described below, V2X systems, methods, and apparatuses may be applicable to both LTE-V2X and NR-V2X as well as other frequencies. Other frequency spectrums other than those covered by LTE-V2X and NR-V2X are also considered to be applicable to the description and as such, the disclosure should not be considered limiting.

<FIG> illustrate example V2X systems in which aspects of the present disclosure may be practiced. The V2X system, provided in <FIG>, provides two complementary transmission modes. A first transmission mode involves direct communications between participants in the local area. Such communications are illustrated in <FIG>. A second transmission mode involves network communications through a network as illustrated in <FIG>.

Referring to <FIG>, the first transmission mode allows for direct communication between different participants in a given geographic location. As illustrated, a vehicle can have a communication with an individual (V2P) through a PC5 interface. Communications between a vehicle and another vehicle (V2V) may also occur through a PC5 interface. In a like manner, communication may occur from a vehicle to other highway components, such as a signal (V2I) through a PC5 interface. In each embodiment illustrated, two-way communication can take place between elements, therefore each element may be a transmitter and a receiver of information. In the configuration provided, the first transmission mode is a self-managed system and no network assistance is provided. Such transmission modes provide for reduced cost and increased reliability as network service interruptions do not occur during handover operations for moving vehicles. Resource assignments do not need coordination between operators and subscription to a network is not necessary, therefore there is reduced complexity for such self-managed systems.

In one, non-limiting embodiment, the V2X system is configured to work in a <NUM> spectrum, thus any vehicle with an equipped system may access this common frequency and share information. Such harmonized/common spectrum operations allows for safe operation. V2X operations may also co-exist with <NUM>. 11p operations by being placed on different channels, thus existing <NUM>. 11p operations will not be disturbed by the introduction of V2X systems. In one non-limiting embodiment, the V2X system may be operated in a <NUM> band that describes/contains basic safety services. In other non-limiting embodiments, the V2X system may support advanced safety services in addition to basic safety services described above. In another non-limiting embodiment, the V2X system may be used in a <NUM> NR V2X configuration, which is configured to interface with a wide variety of devices. By utilizing a <NUM> NR V2X configuration, multi Gbps rates for download and upload may be provided. In a V2X system that uses a <NUM> NR V2X configuration, latency is kept low, for example <NUM>, to enhance operation of the V2X system, even in challenging environments.

Referring to <FIG>, a second of two complementary transmission modes is illustrated. In the illustrated embodiment, a vehicle may communicate with another vehicle through network communications. These network communications may occur through discrete nodes, such as eNodeBs, that send and receive information between vehicles. The network communications may be used, for example, for long range communications between vehicles, such as noting the presence of an accident approximately <NUM> mile ahead. Other types of communication may be sent by the node to vehicles, such as traffic flow conditions, road hazard warnings, environmental/weather reports, service station availability and other like data. Data can be obtained from cloud-based sharing services.

For network communications, residential service units (RSUs) may be utilized as well as <NUM>/<NUM> small cell communication technologies to benefit in more highly covered areas to allow real time information to be shared among V2X users. As the number of RSUs diminishes, the V2X systems may rely more on small cell communications, as necessary.

In either of the two complementary transmission modes, higher layers may be leveraged to tune congestion control parameters. In high density vehicle deployment areas, using higher layers for such functions provides an enhanced performance on lower layers due to congestion control for PHY/MAC.

The vehicle systems that use V2X technologies have significant advantages over <NUM>. 11p technologies. Conventional <NUM>. 11p technologies have limited scaling capabilities and access control can be problematic. In V2X technologies, two vehicles apart from one another may use the same resource without incident as there are no denied access requests. V2X technologies also have advantages over <NUM>. 11p technologies as these V2X technologies are designed to meet latency requirements, even for moving vehicles, thus allowing for scheduling and access to resources in a timely manner.

In the instance of a blind curve scenario, road conditions may play an integral part in decision making opportunities for vehicles. V2X communications can provide for significant safety of operators where stopping distance estimations may be performed on a vehicle by vehicle basis. These stopping distance estimations allow for traffic to flow around courses, such as a blind curve, with greater vehicle safety, while maximizing the travel speed and efficiency.

As noted above, one challenge in V2X systems is to support different types of traffic. The different types of traffic require different types of control information. As a result, a single control channel format is inefficient as the payload may be too large for some types of traffic, resulting in a waste of resources. Further, if multiple formats are used for the single stage to reduce waste of resources, then the number of formats would be too large, thereby resulting in a large number of blind decoding attempts.

<FIG> illustrates one example format for sending content of a control channel, such as a Physical Sidelink Control Channel (PSCCH) to schedule traffic in a Physical Sidelink Shared Channel (PSSCH), in a single transmission, in accordance with certain aspects of the present disclosure. To cover all types of traffic, this format includes information that may not be needed for all types of traffic it schedules. For example, as will be described in greater detail below, certain information, such as Zone ID for distance based negative acknowledgement (NACK) <NUM>, hybrid automatic repeat request (HARQ) ACK/NACK feedback <NUM>, and channel state information-reference signal (CSI-RS) parameters <NUM> may not be needed for all types of traffic. Thus, sending this information when not needed is a waste of resources. As can be seen in the figure, the total payload size <NUM> for a single-stage control information format may be <NUM> bits in order to be able to carry all of the required information.

<FIG> illustrates example operations <NUM> for a transmitting peer device (e.g., a V2X UE), in accordance with certain aspects of the present disclosure. The operations <NUM> may be performed, for example, by a V2X UE 120v shown in <FIG> (e.g., to schedule peer-to-peer traffic to one or more other V2X UEs).

Operations <NUM> begin, at block <NUM>, by generating content for a control channel to schedule peer-to-peer traffic intended for one or more other peer devices, wherein the content comprises a first portion with content that remains constant for different types of traffic and a second portion with content that varies with the different types of traffic. At <NUM>, the UE transmits the first portion of the control channel in a first stage using first time and frequency resources. At <NUM>, the UE transmits the second portion of the control channel in a second stage using second time and frequency resources.

<FIG> illustrates example operations <NUM> for a receiving peer device (e.g., a V2X UE), in accordance with certain aspects of the present disclosure. The operations <NUM> may be performed, for example, by a V2X UE 120v shown in <FIG> (e.g., to process a multi-stage control channel transmission sent by one or more other V2X UEs performing operations <NUM>).

The operations <NUM> begin, at <NUM>, by receiving, in a first stage using first time and frequency resources, a first portion of a control channel to schedule peer-to-peer traffic, the first portion including content that remains constant for different types of traffic. At <NUM>, the UE uses information in the first portion to decode, in a second stage using second time and frequency resources, a second portion of the control channel, the second portion including content that varies with the different types of traffic.

A multi-stage (e.g., <NUM>-stage) transmission as proposed herein may help accommodate future needs and may allow for different sidelink control information (SCI) formats for the second stage. <FIG> illustrates different formats for the second stage, each with different types of information and a different size payload.

As illustrated in <FIG>, the first stage may include resource reservation content. In general, the multi-stage transmission splits the content of a control channel (e.g., PSCCH) into two stages, referred to herein as Control A and Control B.

In general, Control A may include content that is constant for different types of traffic (e.g., resource reservation indication-assist scheduling) and may include information that would assist in the allocation of resource of channel in an efficient way. This information may not allow a UE to decode the actual data it schedules, but may let the UE know what resources have been reserved and the like. Information needed to decode the data may be conveyed in the second stage (Control B). Control A may include information needed to decode control B, like a format indicator.

Some information may be conveyed in either Control A or Control B. For example, Control A could include a ZONE ID and/or DESTINATION ID that may define groups for Groupcast (e.g., Group ID)/Broadcast (e.g., generic like <NUM>)/Unicast (e.g., specific ID of the receiver). A Zone ID may be indicative of location information of the transmitter. The information could also include actual location information instead (e.g., GPS coordinates) and/or a transmitter ID. A UE may decode some information, look at the ID, then know if it has to decode the rest. In some cases, a zone ID may indicate a location of transmitter (e.g., like GPS coordinates). A receiver may use this information to decide if the receiver is too far from the transmitter (e.g., and may ignore the transmission) or if the receiver is in close proximity to the transmitter so the transmission must be important.

The Control A and Control B transmissions may have different amount of protection/aggregation level/repetition (e.g., AL <NUM>, repeating <NUM> times, with much better performance).

In general, the Control B information includes information that varies in content with the types of traffic (e.g., groupcast, broadcast, unicast). It may include additional information (relative to Control A) that is needed only for data decoding.

In some cases, the Control A and Control B information may be sent with different link budgets for first and second stage transmissions. For example, the second stage may not need to have more link budget than data.

By providing information for the second stage via Control A, blind decoding may only need to be performed for the first stage. This may be aided by the reduced payload and may be further aided by limiting the time and location of the Control A transmissions. As illustrated, the total decoding overhead of the first and second stages may be a bit increased relative to a single stage transmission (e.g., total payload may increase due to an additional cyclic redundancy code (CRC)). As illustrated in <FIG>, an example control transmission may take <NUM> bits in one stage control <NUM> with <NUM> bits for future proof, versus <NUM> (e.g., the combination of control A <NUM> and control B <NUM>, e.g., for group-cast traffic) or <NUM> bits (e.g., the combination of control A <NUM> and control B <NUM>, e.g., for unicast traffic) when sent in two stages.

<FIG> show how control and data may be multiplexed in single stage and multi-stage transmissions.

In the example shown in <FIG>, resource mapping for single stage may be <NUM> resource blocks (RBs) x <NUM> symbols, with <NUM> symbols with comb-<NUM> demodulation reference signals (DMRS). This may result in a code rate of approximately <NUM> or <NUM> without reserved bits. For MCS0 for NR, the code rate may be approximately <NUM> (for table <NUM>, <NUM>) and approximately <NUM> (for table <NUM>).

In the mutli-stage examples shown in <FIG>, the first stage Control A information may have a target code rate, for example, of <NUM> (or less), if mapped to two symbols. In some cases, the Control A information may be limited to a single symbol. The code rate for the second stage (Control B) may vary. For example, different aggregation levels can be defined and chosen by the transmitter based on the MCS of data.

There are various options for RE mapping. For example, <FIG> illustrates a first option where Control B is mapped with Control A, which is somewhat similar to a single stage mapping (shown in <FIG>). According to other options, as shown in <FIG>, Control B information may be multiplexed ("piggybacked") with data (e.g., similar to uplink control information (UCI) multiplexing on PUSCH).

There are various options when Control B information is mapped together with Control A information. These options may be illustrated by considering an example of Control B Info of <NUM> bits (e.g., for groupcast as shown in <FIG>). This information could be sent using <NUM> symbol, as shown in <FIG>, which may result in a code rate of approximately <NUM> (e.g., data MCS <NUM>-<NUM> for table <NUM>). As another option, this information could be sent using <NUM> symbols, as shown in <FIG>, which may result in a code rate of approximately <NUM> (e.g., data MCS <NUM>-<NUM> for table <NUM>). As another option, this information could be sent using <NUM> symbols, as shown in <FIG>, which may result in a code rate of approximately <NUM> (e.g., data MCS <NUM>/<NUM>-<NUM> for table <NUM>).

Three aggregation levels (signaled with <NUM> bits) may be sufficient for many types of control B formats. Further, different Control B formats may support only certain aggregation levels (e.g. AGG3 only needed for Control B for groupcast).

There are various options for Quasi Co Location (QCL) assumption on RS for Control A and Control B. For example, for Control A, omni-like transmission may be needed. Control B information may be directed towards an intended receiver only. In unicast, if data DMRS is being pre-coded, then the Control B information may also be precoded so Control-B and data will have similar link budgets.

In some cases, multi stage transmission may support non-QCL and/or different precodings for RS on Control A and/or Control B, in general by specification, or depending on the Control B format (unicast vs. groupcast/broadcast). For groupcast/broadcast, the RS may be QCL'ed. This may present a challenge in certain cases, for example, with carrier frequency offset issues and performance under certain requirements, such as certain speeds of the transmitter and/or receiver.

As illustrated in <FIG>, in some cases, there may be certain problems when Control B is mapped together with Control A. For example, as illustrated in <FIG>, problematic cases may arise if mapping Control B to more than <NUM> symbol depending on speed (e.g., at higher speeds, more DMRS symbols may be needed). One approach to address this problem is to not limit Control B to the same frequency allocation as Control A (e.g., 10RBs). In some cases, the size in RB may be determined, for example, by AGG level, Format, and/or the RB allocation for data. For example, for a low-code rate Control B transmission, <NUM> RBs may be allocated (i.e. data transmission minimum BW is 15RBs). Control B information distributed non-uniformly over frequencies may also be possible (although this may not be ideal).

<FIG> illustrate other options for when Control B is mapped together with Control A. As illustrated, Control B may have different frequency allocation than Control A. One limitation may be that some combinations may not work (e.g., 10RB data transmission at MCS0 with <NUM> symbols for Control B with DMRS pattern <NUM> may not be allowed. In some cases, the Control B may skip the DMRS locaton. In this case, the DMRS location or DMRS format should be indicated in the Control A information.

<FIG> shows another option for Control B mapped information that is similar to UCI multiplexing with PUSCH. The Control B information may be mapped to all layers for the data TB and may have the same modulation as data. In some cases, the RE locations of Control B may need to be specified depending on DMRS pattern density (possible). Control REs may be made more robust than Data REs (e.g., by placing Control REs closer to RS symbols) and/or data may be rate matched (RM) around those REs. This approach may have an advantage in that control can be made to follow data link budget. RE overheads are smaller (albeit at a cost in terms of latency depending on control RE location).

There are various other options for the two stage control proposed herein. For example, the first stage may include all relevant information for broadcast traffic, such that receivers of broadcast traffic would not have to decode the second stage.

Second stage control information may be transmitted in a similar fashion as data, such that DMRS, channel estimation, number of layers, precoding, and the like, are all performed in a similar fashion as data.

There may be multiple formats for the first stage, for example, with RSRP instead of distance for example may be two formats. There may be multiple formats for each traffic type for second stage as well (e.g., with Zone ID present/absent, RSRP/distance, feedback information).

The first stage may not always be accompanied by the second stage. For example, for reservation signals only, there may be no need for a second stage. The first stage may also be used for pre-emption or unbooking of reserved resources. Reserved resources can also be released by transmission of only the first stage.

In some cases, Control A may be configured to be transmitted with a certain periodicity. In some cases, single Control A may be associated with multiple Control B transmissions.

In some cases, certain devices (e.g., RSU/Group leader transmissions) may send Control A transmissions. For example, Control A may be transmitted by RSU or group leader (not associated with a single Control B). Other (member) UEs may transmit on the reserved resources (reserved by Control A) and transmit only Control B. Thus, multiple member UEs may transmit Control B resulting a one-to-many mapping of Control A to Control B transmissions.

Control B transmissions may also occur on their own, for example, with the implicit association to a Control A that has been transmitted in the past. They may also occur on their own for retransmissions of the same packet.

As an example, "at least one of a, b, or c" is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

For example, processors <NUM>, <NUM>, <NUM>, and/or controller/processor <NUM> of the UE <NUM> shown in <FIG> may be configured to perform operations <NUM> of <FIG> and/or operations <NUM> of <FIG>.

In the case of a UE <NUM> (see <FIG>), a user interface (e.g., keypad, display, mouse, joystick, etc.) may also be connected to the bus.

Claim 1:
A method (<NUM>) for wireless communications by a peer device, comprising:
generating (<NUM>) control information to schedule peer-to-peer communication, wherein the control information comprises a first portion with a first set of control information and a second portion with a second set of control information;
transmitting (<NUM>) the first portion of the control information in a first stage using first time and frequency resources, wherein the first portion indicates a control information format of the second portion; and
transmitting (<NUM>) the second portion of the control information in a second stage using second time and frequency resources and the indicated control information format; the method being characterized in that:
content included in the second set of control information varies based on casting type of the peer-to-peer communication; or
the second set of control information comprises information regarding a location of the peer device.