Patent Publication Number: US-2023140371-A1

Title: System and method for transmission indications

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priority under 35 U.S.C. § 120 as a continuation of PCT Patent Application No. PCT/CN2020/100779, filed on Jul. 8, 2020, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The disclosure relates generally to wireless communications and, more particularly, to systems and methods for transmission indications. 
     BACKGROUND 
     In areas where there is weak terrestrial network service or no terrestrial network service, a non-terrestrial network (“NTN”) network may be employed to support connectivity of massive Internet of Things (“IoT”) devices. NTNs such as Geostationary Earth Orbit (“GEO”) satellites or Low Earth Orbit (“LEO”) satellites can provide continental local or regional services. However, special considerations must be made when using NTN networks. 
     The fast movement of satellites relative to a user&#39;s position on earth can lead to Doppler frequency shifting. Further, the distance of a satellite from terrestrial wireless communication devices can result in large transmission round trip times. Thus, the transmissions between satellites and a user may be very lengthy because generally, data in the transmission may be repeated. 
     SUMMARY 
     The example embodiments disclosed herein are directed to solving the issues relating to one or more of the problems presented in the prior art, as well as providing additional features that will become readily apparent by reference to the following detailed description when taken in conjunction with the accompany drawings. In accordance with various embodiments, example systems, methods, devices and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and are not limiting, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of this disclosure. 
     In one embodiment, a method performed by a wireless communication node includes transmitting, by a wireless communication node to a wireless communication device, within an uplink gap or a downlink gap, control information. 
     In another embodiment, a method performed by a wireless communication device includes receiving, by a wireless communication device from a wireless communication node, within an uplink gap or a downlink gap, control information. 
     In yet another embodiment, a method performed by a wireless communication device includes, transmitting by a wireless communication device to a wireless communication node, within an uplink gap or a downlink gap, control information. 
     The above and other aspects and their implementations are described in greater detail in the drawings, the descriptions, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various example embodiments of the present solution are described in detail below with reference to the following figures or drawings. The drawings are provided for purposes of illustration only and merely depict example embodiments of the present solution to facilitate the reader&#39;s understanding of the present solution. Therefore, the drawings should not be considered limiting of the breadth, scope, or applicability of the present solution. It should be noted that for clarity and ease of illustration, these drawings are not necessarily drawn to scale. 
         FIG.  1    illustrates an example cellular communication network in which techniques and other aspects disclosed herein may be implemented, in accordance with some embodiments of the present disclosure. 
         FIG.  2    illustrates block diagrams of an example base station and a user equipment device, in accordance with some embodiments of the present disclosure. 
         FIG.  3    shows a block diagram of an example non-terrestrial communication network, in accordance with some embodiments of the present disclosure. 
         FIG.  4    shows a block diagram of an example non-terrestrial communication network, in accordance with some embodiments of the present disclosure. 
         FIG.  5    illustrates a flow chart of an example method of a base station transmitting control information to a user equipment, in accordance with some embodiments of the present disclosure. 
         FIG.  6    illustrates an example system signaling termination of scheduled transmissions in the time domain, in accordance with some embodiments of the present disclosure. 
         FIG.  7    illustrates an example system signaling termination of scheduled transmissions in the frequency domain, in accordance with some embodiments of the present disclosure. 
         FIG.  8    illustrates an example system transmitting an adjustment to the repeated transmission in the frequency domain using an appended compensation gap, in accordance with some embodiments of the present disclosure. 
         FIG.  9    illustrates an example system transmitting an adjustment to the repeated transmission in the frequency domain using additional compensation gaps, in accordance with some embodiments of the present disclosure. 
         FIG.  10    illustrates a flow chart of an example method of user equipment receiving control information from a base station, in accordance with some embodiments of the present disclosure. 
         FIG.  11    illustrates an example system receiving a control signal, in accordance with some embodiments of the present disclosure. 
         FIG.  12    illustrates a flow chart of an example method of a user equipment transmitting control information to a base station, in accordance with some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Various example embodiments of the present solution are described below with reference to the accompanying figures to enable a person of ordinary skill in the art to make and use the present solution. As would be apparent to those of ordinary skill in the art, after reading the present disclosure, various changes or modifications to the examples described herein can be made without departing from the scope of the present solution. Thus, the present solution is not limited to the example embodiments and applications described and illustrated herein. Additionally, the specific order or hierarchy of steps in the methods disclosed herein are merely example approaches. Based upon design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be re-arranged while remaining within the scope of the present solution. Thus, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or acts in a sample order, and the present solution is not limited to the specific order or hierarchy presented unless expressly stated otherwise. 
     1. Mobile Communication Technology and Environment 
       FIG.  1    illustrates an example wireless communication network, and/or system,  100  in which techniques disclosed herein may be implemented, in accordance with an embodiment of the present disclosure. In the following discussion, the wireless communication network  100  may be any wireless network, such as a cellular network or a narrowband Internet of things (NB-IoT) network, and is herein referred to as “network  100 .” Such an example network  100  includes a base station  102  (hereinafter “BS  102 ”) and a user equipment device  104  (hereinafter “UE  104 ”) that can communicate with each other via a communication link  110  (e.g., a wireless communication channel), and a cluster of cells  126 ,  130 ,  132 ,  134 ,  136 ,  138  and  140  overlaying a geographical area  101 . In  FIG.  1   , the BS  102  and UE  104  are contained within a respective geographic boundary of cell  126 . Each of the other cells  130 ,  132 ,  134 ,  136 ,  138  and  140  may include at least one base station operating at its allocated bandwidth to provide adequate radio coverage to its intended users. 
     For example, the BS  102  may operate at an allocated channel transmission bandwidth to provide adequate coverage to the UE  104 . The BS  102  and the UE  104  may communicate via a downlink radio frame  118 , and an uplink radio frame  124  respectively. Each radio frame  118 / 124  may be further divided into sub-frames  120 / 127  which may include data symbols  122 / 128 . In the present disclosure, the BS  102  and UE  104  are described herein as non-limiting examples of “communication nodes,” generally, which can practice the methods disclosed herein. Such communication nodes may be capable of wireless and/or wired communications, in accordance with various embodiments of the present solution. 
       FIG.  2    illustrates a block diagram of an example wireless communication system  200  for transmitting and receiving wireless communication signals, e.g., half-duplexing signals, in accordance with some embodiments of the present solution. The system  200  may include components and elements configured to support known or conventional operating features that need not be described in detail herein. In one illustrative embodiment, system  200  can be used to communicate (e.g., transmit and receive) data symbols in a wireless communication environment such as the wireless communication environment  100  of  FIG.  1   , as described above. 
     System  200  generally includes a base station  202  (hereinafter “BS  202 ”) and a user equipment device  204  (hereinafter “UE  204 ”). The BS  202  includes a BS (base station) transceiver module  210 , a BS antenna  212 , a BS processor module  214 , a BS memory module  216 , and a network communication module  218 , each module being coupled and interconnected with one another as necessary via a data communication bus  220 . The UE  204  includes a UE (user equipment) transceiver module  230 , a UE antenna  232 , a UE memory module  234 , and a UE processor module  236 , each module being coupled and interconnected with one another as necessary via a data communication bus  240 . The BS  202  communicates with the UE  204  via a communication channel  250 , which can be any wireless channel or other medium suitable for transmission of data as described herein. 
     As would be understood by persons of ordinary skill in the art, system  200  may further include any number of modules other than the modules shown in  FIG.  2   . Those skilled in the art will understand that the various illustrative blocks, modules, circuits, and processing logic described in connection with the embodiments disclosed herein may be implemented in hardware, computer-readable software, firmware, or any practical combination thereof. To clearly illustrate this interchangeability and compatibility of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps are described generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software can depend upon the particular application and design constraints imposed on the overall system. Those familiar with the concepts described herein may implement such functionality in a suitable manner for each particular application, but such implementation decisions should not be interpreted as limiting the scope of the present disclosure. 
     In accordance with some embodiments, the UE transceiver  230  may be referred to herein as an “uplink” transceiver  230  that includes a radio frequency (RF) transmitter and a RF receiver each comprising circuitry that is coupled to the antenna  232 . A duplex switch (not shown) may alternatively couple the uplink transmitter or receiver to the uplink antenna in time duplex fashion. Similarly, in accordance with some embodiments, the BS transceiver  210  may be referred to herein as a “downlink” transceiver  210  that includes a RF transmitter and a RF receiver each comprising circuitry that is coupled to the antenna  212 . A downlink duplex switch may alternatively couple the downlink transmitter or receiver to the downlink antenna  212  in time duplex fashion. The operations of the two transceiver modules  210  and  230  can be coordinated in time such that the uplink receiver circuitry is coupled to the uplink antenna  232  for reception of transmissions over the wireless transmission link  250  at the same time that the downlink transmitter is coupled to the downlink antenna  212 . In some embodiments, there is close time synchronization with a minimal guard time between changes in duplex direction. 
     The UE transceiver  230  and the base station transceiver  210  are configured to communicate via the wireless data communication link  250 , and cooperate with a suitably configured RF antenna arrangement  212 / 232  that can support a particular wireless communication protocol and modulation scheme. In some illustrative embodiments, the UE transceiver  210  and the base station transceiver  210  are configured to support industry standards such as the Long Term Evolution (LTE) and emerging 5G standards, and the like. It is understood, however, that the present disclosure is not necessarily limited in application to a particular standard and associated protocols. Rather, the UE transceiver  230  and the base station transceiver  210  may be configured to support alternate, or additional, wireless data communication protocols, including future standards or variations thereof. 
     In accordance with various embodiments, the BS  202  may be an evolved node B (eNB), a serving eNB, a target eNB, a femto station, or a pico station, for example. In some embodiments, the UE  204  may be embodied in various types of user devices such as a mobile phone, a smart phone, a personal digital assistant (PDA), tablet, laptop computer, wearable computing device, etc. The processor modules  214  and  236  may be implemented, or realized, with a general purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. In this manner, a processor may be realized as a microprocessor, a controller, a microcontroller, a state machine, or the like. A processor may also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other such configuration. 
     Furthermore, the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in firmware, in a software module executed by processor modules  214  and  236 , respectively, or in any practical combination thereof. The memory modules  216  and  234  may be realized as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In this regard, memory modules  216  and  234  may be coupled to the processor modules  210  and  230 , respectively, such that the processors modules  210  and  230  can read information from, and write information to, memory modules  216  and  234 , respectively. The memory modules  216  and  234  may also be integrated into their respective processor modules  210  and  230 . In some embodiments, the memory modules  216  and  234  may each include a cache memory for storing temporary variables or other intermediate information during execution of instructions to be executed by processor modules  210  and  230 , respectively. Memory modules  216  and  234  may also each include non-volatile memory for storing instructions to be executed by the processor modules  210  and  230 , respectively. 
     The network communication module  218  generally represents the hardware, software, firmware, processing logic, and/or other components of the base station  202  that enable bi-directional communication between base station transceiver  210  and other network components and communication nodes configured to communication with the base station  202 . For example, network communication module  218  may be configured to support internet or WiMAX traffic. In a typical deployment, without limitation, network communication module  218  provides an 802.3 Ethernet interface such that base station transceiver  210  can communicate with a conventional Ethernet based computer network. In this manner, the network communication module  218  may include a physical interface for connection to the computer network (e.g., Mobile Switching Center (MSC)). The terms “configured for,” “configured to” and conjugations thereof, as used herein with respect to a specified operation or function, refer to a device, component, circuit, structure, machine, signal, etc., that is physically constructed, programmed, formatted and/or arranged to perform the specified operation or function. 
     When devices communicate via half-duplex (“HD”), devices may not transmit and receive simultaneously. In other words, a UE can not process UL transmission and DL transmission at the same time. Thus, there is an asymmetric flow for UL and DL data transmission. Examples of these devices may include low-cost narrow band devices that connect to the internet, in other words, narrow band Internet of Things devices (“NB-IoT”) such as sensors and industrial devices. In frequency-division duplexing (“FDD”), separate frequency bands may be employed to transmit UL and DL information. In time-division duplexing (“TDD”), a single frequency band may be employed for UL and DL information, but the transmissions are scheduled to occur during different time slots. 
       FIG.  3    shows a block diagram of an example non-terrestrial communication network  300  including at least one unmanned aerial system based wireless communication nodes. In particular,  FIG.  3    shows a communication network  300  including a satellite or an unmanned aerial vehicle (UAV)  302 , UE  304 , a gateway  306  and a data network  308 . The satellite  302  can serve as a platform for a base station, such as, for example, the BS  102  and  202  discussed above in relation to  FIGS.  1  and  2   , and the UE  304  can be similar to the UE  104  and  204  discussed above in relation to  FIGS.  1  and  2   . The UE  304  and the BS on the satellite  302  can communicate over a communication link  310 , and the BS on the satellite  302  and the gateway  306  can communicate over a feeder link  312 . The gateway  306  can communicate with the data network  308  over a data link  314 . 
       FIG.  4    shows another example non-terrestrial communication network  400  including at least one unmanned aerial system based wireless communication nodes. The communication network  400  shown in  FIG.  4    is similar to the communication network  300  shown in  FIG.  3   , but include an additional satellite or UAV platform  402 .  FIG.  4    depicts the scenario where the communication network includes a constellation of satellites that allow communication between the UE and the gateway or data network. 
     The gateway can be one of several gateways that can provide connectivity between satellite  302 / 402  and the data network  308 , which can be a public terrestrial data network. The gateways can be deployed across the satellite&#39;s targeted coverage area, which can include regional or continental coverage area. In examples where the satellite is a non-geostationary earth orbit satellite (“non-GEO satellite”), the satellite can be served successively by one or several gateways at a time. The communication network can ensure that there is the service link and the feeder link continuity is maintained between successive gateways with sufficient time duration to proceed with mobility anchoring and handover. In some examples, the UE in a cell may be served by only one gateway. 
     The satellite can implement either a transparent or a regenerative (with on-board processing) payload. The satellite can generate several beams over a service area that can be bounded by its field of view, which can depend on the on-board antenna characteristics and a minimum elevation angle of the satellite. The footprints of the beams on the surface of the earth can be elliptical in shape. In instances where the satellite implements transparent payload, the satellite may carry out radio filtering, frequency conversion, and amplification, thereby repeating the signals. In instances where the satellite platform implements regenerative payload, the satellite can carry out radio frequency filtering, frequency conversion, amplification, as well as demodulation/modulation, switching and/or routing, coding/modulation, etc., effectively carrying out functions, at least in part, of a base station on-board the satellite. 
     In instances where the communication system includes a constellation of satellites, such as for example, the communication system shown in  FIG.  4   , the network can include an inter-satellite link (“ISL”)  412 . In some such instances, the satellites can implement regenerative payload. The ISL can may operate in RF or in optical frequency bands. 
     Table 1 below lists various types of satellites that can be used to implement the satellite/UAV  302  and  402  shown in  FIGS.  3  and  4   . The types of satellites and the corresponding information shown in Table 1 are only examples and are not limiting, as other types of platforms and satellites can also be utilized. 
     
       
         
           
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                 Typical beam 
               
            
           
           
               
               
               
               
            
               
                 Platforms 
                 Altitude range 
                 Orbit 
                 footprint size 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Low-Earth Orbit 
                 300-1500 
                 km 
                 Circular around 
                 100-500 
                 km 
               
               
                 (LEO) satellite 
                   
                   
                 the earth 
               
               
                 Medium-Earth 
                 7000-25000 
                 km 
                   
                 100-500 
                 km 
               
               
                 Orbit (MEO) 
               
               
                 satellite 
               
               
                 Geostationary 
                 35 786 
                 km 
                 notional station 
                 200-1000 
                 km 
               
               
                 Earth Orbit 
                   
                   
                 keeping position 
               
               
                 (GEO) satellite 
                   
                   
                 fixed in terms of 
               
            
           
           
               
               
               
               
               
            
               
                 UAS platform 
                 8-50 km (20 
                 elevation/azimuth 
                 5-200 
                 km 
               
               
                 (including 
                 km for HAPS) 
                 with respect to a 
               
            
           
           
               
               
               
               
               
               
            
               
                 HAPS) 
                   
                   
                 given earth point 
                   
                   
               
               
                 High Elliptical 
                 400-50000 
                 km 
                 Elliptical around 
                 200-1000 
                 km 
               
               
                 Orbit (HEO) 
                   
                   
                 the earth 
               
               
                 satellite 
               
               
                   
               
            
           
         
       
     
     In some embodiments, GEO satellite and UAS platforms can be used to provide continental, regional, or local service. In some embodiments, a constellation of LEO and MEO satellites can be used to provide services in both northern and southern hemispheres. In some instances, constellation of satellites can even provide global coverage including the polar regions. In some such instances, appropriate orbit inclination, ISLs and beams can be selected. 
     2. Base Station Transmits Control Information 
     DL and UL transmission between satellites and users can be very lengthy because there may be a need to repeat the transmission various times. Thus, there may be a schedule of repeated transmissions such that the same transmission is repeated n times. The schedule of repeated transmissions may increase the performance of the receiver. In some embodiments, a BS may transmit control information such that the repeated transmission schedule may be adjusted. In other words, the configuration of the repeated transmission schedule may be adjusted. The control information may include at least one of broadcasting information, synchronization information, or a reference signal (“RS”). In some embodiments, repeated transmission schedules may be adjusted by control information where the control information includes beam switching information, a number of missed repeated transmissions, or termination information. In some embodiments, the BS may process the control information. Alternatively, the BS may process the repeated transmission information. The BS may process the control information and/or the repeated transmission information by scrambling, modulating, and/or resource mapping the information before it is transmitted. 
     In some embodiments, a transmission may not completely end in one service beam because of the BS&#39;s movement and long propagation delays. The propagation delay may be the time associated with the transmission of one signal by a BS and the reception of that signal at a UE. Subsequently, a BS may determine to continue the transmission via a different service beam. In other words, the BS may determine to switch from a first resource to a second, different resource. For example, a resource may be associated with a beam. In other words, in response to a UE moving out of a first beam coverage, a BS may indicate beam switching should occur and a second beam may be employed for a next repeated transmission. Alternatively, a BS may indicate beam switching should occur in response to the receiver power of a UL signal in a first beam being smaller than the receiver power of UL signal in a second beam. In other words, the transmitting beam may switch from a first resource to a second, different resource. In some embodiments, the information indicating that the beam may be switched may be transmitted in the form of a 1 bit flag in a control field in the transmitted signal. In other embodiments, the information indicating that the beam may be switched may be transmitted by indicating a second beam to switch to. 
     In some embodiments, in response to the beam switch, partial repeated data may not be successfully received. For example, PUSCH may be missed. In other words, when the BS determines to switch beams, data may not successfully be received at the BS. In some embodiments, the number of repetitions missed by the BS may be 2′, where n may be based on the switch time, round-trip time, and the numerology, for example, of a PUSCH transmission. In one example, a subcarrier space may be 3.75 kHz and the duration of a PUSCH transmission may be 32 ms. When the subcarrier space is 15 kHz, the duration of a PUSCH transmission may be 1 ms, 2 ms, 4 ms or 8 ms. Thus, in addition to indicating the beam switching information, the BS may indicate a number of missed PUSCH transmissions. 
     In some embodiments, in response to the BS successfully decoding the transmitted data, the subsequent repeated transmissions may not be necessary. For example, a transmission may be scheduled to repeat n times. In response to the BS successfully decoding PUSCH, PRACH and/or PUCCH in x transmissions, where x&lt;n, the remaining n−x transmissions may not be transmitted. In other words, the BS may signal to the UE via termination information that the UE may stop transmitting a portion of the scheduled repeated transmissions. For example, the UE may stop current transmission and subsequent repeated transmissions, and the current schedule/transmission may come to an end. Subsequently, the UE may be scheduled via other DL control information or high layer signaling. In another example, the UE may stop transmitting the remaining transmissions. The BS may signal the termination information to improve system efficiency and reduce power consumption. In some embodiments, the termination information may be transmitted in the form of a 1 bit flag in a control field of the transmitted signal. 
     To compensate for Doppler frequency offsets and propagation delay offsets based on the distance of a UE from a BS and the speed at which the BS may be moving, a UE may insert a UL gap or DL gap between UL or DL transmissions. During the gap, the timing and/or frequency re-synchronization may occur between the UE and the BS. The UL and/or DL gap may be called a compensation gap. 
     In some embodiments, the compensation gap may be inserted at the end of a maximum continuous UL transmission. In other embodiments, the compensation gap may occur after Physical Random Access Channel (“PRACH”) transmission, Physical Uplink Shared Channel (“PUSCH”) transmissions, and Physical Uplink Control Channel (“PUCCH”) transmission. The gap may be inserted and/or interrupt a transmission periodically. For example, the gap may be inserted every 256 ms. In some embodiments, the gap may be 40 ms long. In some embodiments, when the compensation gap is inserted after a DL transmissions, the period of the DL compensation gap for a first UE may need to consider the schedule of other DL transmissions of other UEs. For example, long DL repeated transmissions may occupy an entire channel. Thus, the timing of the compensation gap after DL transmissions may be adjusted for other UE transmissions. 
     The compensation gap may be employed to transmit the control information. The BS may transmit the control information such that the control information may be received by the UE. In some embodiments, the BS may determine the time to transmit the control information not earlier than a time-domain length before the beginning of the compensation gap, and not later than the time-domain length before the end of the compensation gap. In some embodiments, the time-domain length may be based on one or more propagation delays. In other words, the BS may consider propagation delays when determining when to transmit the control information. 
     In some embodiments, a timing may be determined to transmit the control information, the timing of the determining beginning after the start of the compensation gap. The determination of the timing to transmit the control information may be based on the BS&#39;s reception of data and preparing of the transmission of data. The determination of the timing to transmit the control information may be one or more symbols, slots, or subframes. 
       FIG.  5    illustrates a flow chart of an example method of a BS transmitting control information to a UE. As described in  501 , a BS may transmit control information in a UL or DL gap to a UE. The control information may adjust the repeated transmission schedule and may include information related to beam switching information, a number of missed repeated transmissions, or termination information, as discussed herein. 
       FIG.  6    illustrates an example system  600  signaling termination of scheduled transmissions in the time domain, according to some embodiments. The system  600  may include a BS  601  and a UE  602  transmitting and receiving in the time domain. The UE  602  may transmit, for example UL PUSCH  603  during designated time slots. A number n may be the scheduled number of repeated transmissions that the UE  602  is scheduled to transmit UL PUSCH  603 . Thus, UL PUSCH  603  may be repeated n times, where each UL PUSCH  603  other than the first UL PUSCH  603 , may be preceded by a compensation gap  604 . In one example, after four transmissions  605 , where 4&lt;n, the BS  601  may successfully decode the UL PUSCH  603 . Upon successfully decoding the UL PUSCH  603 , the UE  602  may not need to repeat the UL PUSCH  603  transmissions. Thus, the BS  601  may insert termination information  606  during the compensation gap  604  to be received at UL Gap  607 . The termination information may be transmitted after the BS  601  decodes the UL PUSCH  603 . Thus, UE  602  may preserve power and efficiency by terminating the UL PUSCH  603  repeated transmissions before the originally scheduled n times. 
       FIG.  7    illustrates an example system  700  signaling termination of scheduled transmissions in the frequency domain duplex system, according to some embodiments. The system  700  may include a BS  701  and a UE  702  transmitting and receiving in DL subframe and UL gap. The UE  702  may transmit, for example, UL PUSCH  703  on a certain UL frequency band. A number n may be the scheduled number of repeated transmissions that UE  702  is scheduled to transmit UL PUSCH  703 . Thus, UL PUSCH  703  may be repeated n times, where each UL PUSCH  703  other than the first UL PUSCH  703  may be preceded by a compensation gap  704 . In one example, after four transmissions  706 , where 4&lt;n, the BS  701  may successfully decode the UL PUSCH  703 . Upon successfully decoding the UL PUSCH  703 , the UE  702  may not need to repeat the UL PUSCH  703  transmissions. Thus, the BS  701  may process and prepare termination information  707 . The processing and preparing of the termination information may be performed such that the termination information may be transmitted and received by UE  702  during the next UL Gap  704 , specifically UL Gap  708 . The termination information  707  may be processed and prepared after the BS  701  decodes the UL PUSCH  703 . Thus, UE  702  may preserve power and efficiency by terminating the UL PUSCH  703  repeated transmissions before the originally scheduled n times. 
     In some embodiments, a second compensation gap may occur after the first compensation gap. As discussed herein, the compensation gap may be adjusted for DL transmissions. In other words, the timing of the compensation gap after DL transmissions may be adjusted for other UE transmissions. Thus, the second compensation gap may be adjusted for other UE transmission when implemented for DL transmissions. 
     Control information may be transmitted or received during the first compensation gap or second compensation gap. The first compensation gap and second compensation gap may have different beginning times. In other words, there may be a first UL gap and a second UL gap, where the first and second UL gaps have different beginning times. Further, there may be a first DL gap and a second DL gap, where the first and second DL gaps have different beginning times. In some embodiments, the second compensation gap may be inserted between two first compensation gaps. For example, if the period of the first compensation gaps is 256 ms, a first compensation gap may be at 0 ms and 256 ms. The second compensation gap may be inserted at 128 ms. In some embodiments, the second compensation gap may be the same length of time as the first compensation gap. In some embodiments, the second compensation gap may be 40 ms long. In other embodiments, the second compensation gap may be a fraction of the length of time of the first compensation gap. 
     In some embodiments, the second compensation gap may be inserted by the BS after a round trip time. The round trip time may be the time for a transmission from the BS to reach the UE and a subsequent transmission from a UE to reach the BS. In some embodiments, the BS may insert an additional gap between the first and second compensation gaps based on a fixed time offset. 
     In some embodiments, the additional compensation gap can be appended to a first and/or second compensation gap such that the duration of the compensation gap is extended. In other words, a UL gap may be appended by an additional UL gap. Further, a DL gap may be appended by an additional DL gap. As discussed herein, the compensation gap may be adjusted for DL transmissions. In other words, the timing of the compensation gap after DL transmissions may be adjusted for other UE transmissions. Thus, the additional compensation gap may be adjusted when implemented for DL transmissions to consider other UE transmissions. 
     This compensation gap with an appended compensation gap may be called an extended compensation gap. The extension of the compensation gap, whether a UL compensation gap or DL compensation gap, may be based on comparing a plurality of propagation delays. The extended compensation gap may be a UL or DL gap in the time domain. In some embodiments, a BS may configure a plurality of UL or DL extended gaps in the time domain. An extended compensation gap may increase the likelihood that the UE receive the BS transmission within the compensation gap. An extended compensation gap may increase the overhead of the compensation gap. 
     In some embodiments, a first UL gap and a second UL gap may be inserted into a single UL gap such that at least one of PUSCH, PUCCH, or PRACH transmission is postponed. 
       FIG.  8    illustrates an example system  800  transmitting an adjustment to the repeated transmission in the frequency domain using an appended compensation gap, according to some embodiments. The system  800  may include a UE  802  and BS  801 A-B that can both receive and transmit, where the receiver side BS  801 A and the transmitter side BS  801 B do not operate simultaneously. 
     In some embodiments, the adjustment to the repeated transmission may include adjusting the repeated transmission such that BS  801  indicates beam switching is to occur. In some embodiments, BS  801 B may transmit a flag in the control field that indicates beam switching is occurring. In other embodiments, BS  801 B may transmit a new beam source, indicating that beam switching is occurring. In response to BS  801  determining that beam switching should occur, BS  801 B may deliver the beam switch information such that the UE  802  receives the beam switch information in the closest compensation gap after BS  801  makes the beam switch determination. For example, BS  801  may make a determination to beam switch when a UE moves out of the first beam coverage or the receiver power of a UL signal in a first beam is smaller than the receiver power of a UL signal in a second beam, BS  801  may determine that a beam switch is appropriate and prepare the control information before UL Gap  804  such that BS  801 B is ready to transmit the adjusted control information during UL Gap  804 , specifically at UL Gap  807 . The propagation delay  806  may be the time between BS  801 B transmitting the control information, the control information containing the beam switch information, and UE  802  receiving the control information at UL Gap  807 . Appended UL Gap  805  may be inserted such that UE  802  shall receive the control information within the UL Gap, has time to process the received control information, and adjust for the next UL PUSCH  803  transmission. 
       FIG.  9    illustrates an example system  900  transmitting an adjustment to the repeated transmission using additional compensation gaps, according to some embodiments. The system  900  may include a UE  902  and BS  901 A-B that can both receive and transmit, where the receiver side BS  902 A and the transmitter side  902 B do not operate simultaneously. 
     In some embodiments, the adjustment to the repeated transmission may include adjusting the repeated transmission such that BS  901  indicates beam switching is to occur. In some embodiments, BS  901 B may transmit a flag in the control field that indicates beam switching is occurring. In other embodiments, BS  901 B may transmit a new beam source, indicating that beam switching is occurring. In response to BS  901  determining that beam switching should occur, BS  901 B may transmit the beam switch information such that the UE  902  receives the beam switching information in the closest compensation gap after BS  901  makes the beam switch determination. BS  901  may determine that a beam switch is appropriate and prepare the control information such that BS  801 B is ready to transmit the adjusted control information during a UL Gap. In some embodiments, for example, when the propagation delay  906  is long, an Additional Gap  905  may be inserted in between UL Gaps  904 . The Additional Gap  905  allows UE  902  to receive information from BS  901 B when there are long propagation delays. Thus BS  901 B may transmit information to UE  902  during UL Gap  904  or Additional Gap  905 . 
     After a BS transmits the control information, a UE may receive the control information in a compensation gap.  FIG.  10    illustrates a flow chart of an example method of a UE receiving control information from a BS. As described in  1001 , a UE may receive control information in a UL or DL gap from a BS. The control information may adjust the repeated transmission schedule and may include beam switching information, a number of missed repeated transmissions, or termination information, as discussed herein. 
       FIG.  11    illustrates an example system  1100  receiving a control signal, according to some embodiments. The system  1100  may include a BS  1101  and a UE  1102  transmitting and receiving in the time domain. The UE  1102  may receive, for example, a transmitted control signal at a UL gap  1104  indicated by  1106 . The control signal may be received at  1106 , which may be one propagation delay  1105  after the control signal was transmitted by BS  1101 . 
     A UE may receive control information from a BS. The control information may be received in a UL or DL compensation gap. As discussed herein, the compensation gap may be adjusted for DL communication. In other words, the timing of the compensation gap after DL reception may be adjusted for other UE transmissions. 
     In some embodiments, control information received in compensation gaps may adjust repeated transmission schedules by including beam switching information, a number of missed repeated transmissions, or termination information. In some embodiments, the UE may receive information about DL transmission in a UL compensation gap. In some embodiments, the control information may be received after the start of the compensation gap. In some embodiments, the control information may be received during one or more of: symbols, slots, subframes or frames. In some embodiments, the control information may be received after one or more propagation delays. In some embodiments, the UE may need to process the control information. In alternate embodiments, the UE may need to process the repeated transmission information. The UE may process the control information and/or the repeated transmission information by resource demapping, demodulations, and/or descrambling. 
     In some embodiments, a transmission may not be completely received in one service beam because of the BS&#39;s movement and long propagation delays. Subsequently, a UE may need to continue receiving the transmission at a different service beam. In other words, the UE may determine to switch from a first resource to a second, different resource. In some embodiments, the UE may determine to switch resources based on the determination that the transmission is not complete. In other embodiments, the UE may determine to switch resources based on the control information received. In the event that another beam is to be employed for a next repeated DL transmission, a UE may receive beam switching information. In other words, the UE may track the BS&#39;s beam switch from a first resource to a second, different resource based on the received control information. In some embodiments, the information indicating that the beam may be switched may be received in the form of a 1 bit flag in a control field in the transmitted signal. In other embodiments, the information indicating that the beam may be switched may be received by indicating a second beam that is being switched to. 
     In some embodiments, in response to the beam switch, data may not be successfully transmitted to the BS. In some embodiments, the UE may receive control information indicating a certain number of missed data, for example missed PUSCH. In some embodiments, the missed data may be caused by the BS determining that a beam switching is to occur. In response to the UE receiving information indicating that data has been missed, the UE may determine a number of repeated transmissions such that the information missed by the BS is communicated to the BS. The UE may determine the number of repeated transmissions based on an initially configured value, signaling, and/or propagation delays. In some embodiments, if information was missed by the BS because the BS was determining to switch beams, the UE may transmit the missed data to the newly scheduled beam. 
     In some embodiments, in response to the BS successfully decoding the transmitted data, the subsequent repeated transmissions may not be necessary. For example, a transmission may generally be repeated n times. In response to the BS successfully decoding PUSCH, PRACH and/or PUCCH in x transmissions, where x&lt;n, the remaining n−x transmissions may not be transmitted by the UE. In other words, the UE may be notified, via received termination information from the BS, that the UE may stop transmitting a portion of the scheduled repeated transmissions. For example, the UE may stop transmitting the remaining scheduled repeated transmissions. The UE&#39;s system efficiency and power may be improved by not transmitting the remainder of the n−x transmissions. In some embodiments, the termination information may be received in the form of a 1 bit flag in a control field in the transmitted signal. 
     3. User Equipment Transmits Control Information 
     DL and UL transmission between satellites and users can be very lengthy because there may be a need to repeat the transmission various times. In some embodiments, a UE may transmit control information in an UL or DL compensation gap such that the repeated transmission schedule may be adjusted. In some embodiments, repeated transmission schedules may be adjusted by control information where the control information includes beam switching information or termination information. 
       FIG.  12    illustrates a flow chart of an example method of a UE transmitting control information to a BS. As described in  1201 , a UE may transmit control information in a UL or UL gap to a BS. The control information may adjust the repeated transmission schedule and may include information related to beam switching information and termination information, as discussed herein. 
     In some embodiments, a transmission may not completely end in one service beam because of the BS&#39;s movements and long propagation delays. In some embodiments, it may be advantageous to continue transmitting in a different service beam. As discussed herein, transmissions may be interrupted by compensation gaps for timing and/or frequency resynchronization. Generally, the frequency resource of each beam of a satellite and/or BS is pre-allocated. The pre-allocated beam resource may be based on a reference signal. 
     In some embodiments, a UE may determine that beam switching should occur based on measurements of a reference signal. In other words, transmissions scheduled to occur via certain beams may be adjusted. For example, the UE may determine to switch beams from beam  1  to beam  2  during a scheduled repeated transmission. In other words, a UE transmitting PUSCH on beam  1 , that is scheduled to repeat the transmission of PUSCH on beam  1 , may switch beams and subsequently transmit PUSCH on beam  2 . In some embodiments, the UE processes beam switching within a compensation gap and may begin transmitting the repeat transmission after the last symbol of the compensation gap. 
     The UE may determine to switch beams if the resources on the new beam are suitable for transmission. For example, if the resources in beam  2  are available, the UE may determine to switch to beam  2 . In other words, the UE may transmit switching information indicative of switching from a first resource to a second, different resource. For example, the UE may transmit switching information in the form of a raised beam switch flag. 
     In some embodiments, resources of a single beam may be shared by UEs. In one example, a first UE may be transmitting to a BS via a beam. A BS may determine that the first UE was switched in response to the BS receiving beam information from a second UE. The BS may allocate the resources from the first UE to a second UE and stop transmission with the first UE. 
     The UE that determines that beam switching should occur may transmit the beam switching information in a switching compensation gap. The switching compensation gap may have a duration of one or more symbols, slots or subframes. In some embodiments, the switching compensation gap may consume resources of the scheduled UL compensation gap. For example, the switching compensation gap may occur at the end of a scheduled UL compensation gap. Alternatively, the switching compensation gap may occur at the beginning of a scheduled UL compensation gap. Further, the switching compensation gap may denote one or more time-domain resources, such as slots or symbols, which may be used as a feedback transmission from the BS. 
     The BS may pre-assign dedicated resources for use in transmission to a UE during the feedback transmission in response to the switching compensation gap. The BS may determine the pre-assigned resources based on UE reports of the quality of neighboring beams. 
     In alternate embodiments, the information provided to the BS may be limited. For example, the UE may not provide the BS with an indication of beam switching. For example, a BS may not indicate beam switching by raising a flag in the control field. Further, a UE may not indicate the number of missed repeated transmissions, the missed repeated transmissions caused by the beam switching. 
     The BS may expect the UE to transmit repeated transmissions, for example PUSCH repetitions, during the scheduled transmission times. In the event the UE beam switches and does not transmit beam switching information or a number of missed repeated transmissions, the BS may fail to detect the scheduled transmission at the scheduled service beam. In some embodiments, in response to failing to detect the scheduled transmission at the scheduled service beam, the BS may blindly detect and/or search other beams for the scheduled transmissions. In the event that the BS searches for the repeated transmissions, the BS may tolerate some loss of the repeated transmissions while the BS is searching for the repeated transmissions on different beam resources. 
     In some embodiments, a UE may successfully decode the DL transmission before the transmission has repeated the scheduled n number of times. For example, the UE may successfully decode Physical Downlink Shared Channel (“PDSCH”) in x transmissions, where x&lt;n. The UE may determine to stop the scheduled transmissions early, for example, after x transmissions. Thus, the remaining n-−x scheduled transmissions may be terminated. Thus, the UE may transmit termination information indicative of terminating a portion of the scheduled repeated transmissions. For example, a first UE may transmit termination information and then begin waiting for feedback or acknowledgement from the BS. The first UE may signal to the BS via the termination information that the BS may stop current transmission and subsequent repeated transmissions. In response to receiving the termination information and transmitting the acknowledgement to the first UE, the BS may schedule the first UE or a second UE. In another example, a UE may transmit termination information indicative of terminating the remaining scheduled repeated transmissions. Terminating the remaining scheduled transmissions may improve system efficiency and save power. The termination signal may be transmitted from the BS to the UE in a pre-allocated DL compensation gap. The pre-allocated DL compensation gap may replace a duration of the compensation gap. For example, the pre-allocated DL compensation gap may be transmitted for several symbols, slots, or subframes at the beginning or end of the compensation gap. 
     In other embodiments, a termination signal may not be transmitted. Instead, during the remaining n−x scheduled transmissions, the UE may not transmit anything. 
     While various embodiments of the present solution have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. Likewise, the various diagrams may depict an example architectural or configuration, which are provided to enable persons of ordinary skill in the art to understand example features and functions of the present solution. Such persons would understand, however, that the solution is not restricted to the illustrated example architectures or configurations, but can be implemented using a variety of alternative architectures and configurations. Additionally, as would be understood by persons of ordinary skill in the art, one or more features of one embodiment can be combined with one or more features of another embodiment described herein. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described illustrative embodiments. 
     It is also understood that any reference to an element herein using a designation such as “first,” “second,” and so forth does not generally limit the quantity or order of those elements. Rather, these designations can be used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements can be employed, or that the first element must precede the second element in some manner. 
     Additionally, a person having ordinary skill in the art would understand that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits and symbols, for example, which may be referenced in the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. 
     A person of ordinary skill in the art would further appreciate that any of the various illustrative logical blocks, modules, processors, means, circuits, methods and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two), firmware, various forms of program or design code incorporating instructions (which can be referred to herein, for convenience, as “software” or a “software module), or any combination of these techniques. To clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware or software, or a combination of these techniques, depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in various ways for each particular application, but such implementation decisions do not cause a departure from the scope of the present disclosure. 
     Furthermore, a person of ordinary skill in the art would understand that various illustrative logical blocks, modules, devices, components and circuits described herein can be implemented within or performed by an integrated circuit (IC) that can include a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, or any combination thereof. The logical blocks, modules, and circuits can further include antennas and/or transceivers to communicate with various components within the network or within the device. A general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration to perform the functions described herein. 
     If implemented in software, the functions can be stored as one or more instructions or code on a computer-readable medium. Thus, the steps of a method or algorithm disclosed herein can be implemented as software stored on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program or code from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. 
     In this document, the term “module” as used herein, refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purpose of discussion, the various modules are described as discrete modules; however, as would be apparent to one of ordinary skill in the art, two or more modules may be combined to form a single module that performs the associated functions according embodiments of the present solution. 
     Additionally, memory or other storage, as well as communication components, may be employed in embodiments of the present solution. It will be appreciated that, for clarity purposes, the above description has described embodiments of the present solution with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic elements or domains may be used without detracting from the present solution. For example, functionality illustrated to be performed by separate processing logic elements, or controllers, may be performed by the same processing logic element, or controller. Hence, references to specific functional units are only references to a suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization. 
     Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other implementations without departing from the scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as recited in the claims below.