Patent Publication Number: US-2022239454-A1

Title: Efficient Bandwidth Adaptation for a Wideband Carrier

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation, and claims priority under 35 U.S.C. § 120 from nonprovisional U.S. patent application Ser. No. 16/790,937, entitled “EFFICIENT BANDWIDTH ADAPTATION FOR A WIDEBAND CARRIER,” filed on Jun. 14, 2021, the subject matter of which is incorporated herein by reference. Application Ser. No. 16/790,937, in turn, is a continuation, and claims priority under 35 U.S.C. § 120 from nonprovisional U.S. patent application Ser. No. 16/145,704, entitled “EFFICIENT BANDWIDTH ADAPTATION FOR A WIDEBAND CARRIER”, filed on Sep. 28, 2018, the subject matter of which is incorporated herein by reference. Application Ser. No. 16/145,704, in turn, claims priority under 35 U.S.C. § 119 US provisional application 62/565,191, entitled “Methods of Power-efficient Bandwidth Adaptation in a Wideband Carrier” filed on Sep. 29, 2017, and application 62/585,005 entitled “Methods of Efficient Bandwidth Adaptation for a Wideband Carrier” filed on Nov. 13, 2017, and application 62/586,977 entitled “Efficient Bandwidth Adaptation Operation in a Wideband Carrier” filed on Nov. 16, 2017, the subject matter of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The disclosed embodiments relate generally to wireless communication, and, more particularly, to methods and apparatus for efficient bandwidth adaptation for wideband carrier. 
     BACKGROUND 
     Mobile networks communication continues to grow rapidly. The mobile data usage will continue skyrocketing. New data applications and services will require higher speed and more efficient. Large data bandwidth application continues to attract more consumers. New technologies are developed to meet the growth such as carrier aggregation (CA), which enables operators, vendors, content providers and the other mobile users to meet the increasing requirement for the data bandwidth. However, carrier aggregation assumes multiple RF chains for signal reception even for physically contiguous spectrum, which introduces long transition time to activate more carriers from one carrier for larger data bandwidth and decreases the efficiency of the data transmission. 
     In frequency bands above 3 GHz, there could be a block of physically continuous spectrum up to hundreds of MHz. The single carrier operation for such large continuous spectrum is more efficient in both the physical (PHY) control, with lower control signaling overhead, and PHY data, with higher trunking gains. It is, therefore, to configure the large contiguous spectrum for large data transmission instead of configuring multiple small spectrum resources. However, from the system level, not all the user equipment (UEs) require large channel bandwidth. Further, for each UE, not all applications require large channel bandwidth. Given that wideband operation requires higher power consumption, the use of the large spectrum resource for control signaling monitoring and low-data-rate services is not ideal for power saving and bandwidth efficiency. 
     A 5G base station/gNB would support enabling reduced UE bandwidth capability within a wideband carrier and enabling reduced UE power energy consumption by bandwidth adaptation. For UEs configured with multiple bandwidth parts (BWPs), the UE can switch BWP to enable faster data transmission or reduce power consumption or for other purposes. The issues remain in implementing the BWP management for UE efficiently. 
     Improvements and enhancements are required to facilitate 5G base station to support UEs operating with multiple BWPs to facilitate the power-efficient operation for wider bandwidth. 
     SUMMARY 
     Apparatus and methods are provided for efficient bandwidth adaptation for wideband carrier. In one novel aspect, timer-based active BWP switching are provided. The UE with multiple BWP configured starts a BWP timer upon detecting one or more BWP timer starting triggering events, resets the BWP timer upon detecting one or more BWP timer resetting triggering events, and switches to the default BWP upon expiration of the BWP timer. The UE sets an initial BWP or one of the configured BWPs as a default BWP based on a higher-layer configuration. In one embodiment, the BWP timer starting triggering event is successfully decoding a physical-layer signaling to switch away from the default BWP for a downlink (DL) to an active BWP other than the default BWP. In another embodiment, the BWP timer resetting triggering event is successfully decoding a downlink control information (DCI) to schedule one or more physical downlink shared channel (PDSCHs) in a BWP that is not the default BWP. In one embodiment, the UE is in a discontinuous reception (DRX) mode, and wherein a downlink (DL) active BWP during a DRX-on duration is set to be the default BWP for DL. In another embodiment, the UE is in the DRX mode and one of the configured DL BWP is set as the downlink (DL) active BWP during a DRX-on duration based on a higher-layer signaling. In one embodiment, the UE performs DCI monitoring on the default BWP for DL during the DRX-on duration. In one embodiment, the UE is in a discontinuous reception (DRX) mode, and wherein the UE switches to an active BWP different from the default BWP during the DRX-on duration upon receiving higher-layer signaling. The higher-layer signaling is RRC signaling, MAC CE or other form of signaling. In one embodiment, the UE is in a discontinuous reception (DRX) mode, and wherein BWP timer starting triggering event is successfully decoding a physical-layer signaling to switch away from the default BWP to an active BWP other than the default BWP. The UE starts the BWP timer upon detecting the physical-layer signaling to switch away from the default BWP to an active BWP other than the default BWP. In another embodiment, the UE is in a DRX mode, and wherein the BWP timer resetting triggering event is successfully decoding a DCI to schedule one or more physical downlink shared channel (PDSCHs) in a BWP that is not the default BWP for DL. In one embodiment, each BWP is configured with downlink (DL)/uplink (UL) pair, and wherein the BWP timer is restarted upon detecting a physical uplink shared channel (PUSCH) scheduled by a physical downlink common channel (PDCCH) in a configured DL/UL BWP pair that is not the default BWP. In yet another embodiment, the BWP timer resetting triggering event is successfully decoding a DCI to schedule one or more physical uplink shared channel (PUSCHs) in a BWP. 
     In another novel aspect, the UE only decodes the DCI indication for active BWP switching in the first three OFDM symbols of a subframe or a slot. The DCI indication for active BWP switching outside the first three OFDM symbols of a subframe or a slot is ignored. The BWP switching command applies to UL BWP and the DL BWP. In one embodiment, the BWP switching command indicates to switch from a default BWP to an active BWP, and wherein the default BWP is configured by a higher-layer signaling. 
     In yet another novel aspect, when the SPS is configured for the serving cell for a UE with multiple BWPs, the SPS is configured for all the BWPs accordingly. In one embodiment, the serving SPS is configured with no downlink control information (DCI) activation, and wherein the configured SPS opportunities remain valid after the UE switches its active BWP. In one embodiment, when the SPS is configured with no DCI activation, only the SPS opportunities in the active BWP are activated after the BWP switching. In yet another embodiment, wherein the serving SPS is configured with downlink control information (DCI) activation, and wherein the configured SPS opportunities are released after the UE switches its active BWP. The switching of the UE&#39;s active BWP is triggered by at least one condition comprising: receiving a DCI scheduling command, and an expiration of a BWP timer. 
     Other embodiments and advantages are described in the detailed description below. This summary does not purport to define the invention. The invention is defined by the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the invention. 
         FIG. 1  illustrates a system diagram of a wireless network with one more BWPs configured in accordance with embodiments of the current invention. 
         FIG. 2  illustrates exemplary diagrams of timer-based active BWP switching in accordance to embodiments of the current invention. 
         FIG. 3  illustrates exemplary diagrams for BWP operation with timer-based BWP switching in the DRX mode in accordance with embodiments of the current invention. 
         FIG. 4  illustrates exemplary diagrams for paired DL/UL BWP with timer-based active BWP switching in accordance with embodiments of the current invention. 
         FIG. 5  illustrates exemplary diagrams for the active BWP switching decoding scheme with OFDM symbols in accordance with embodiments of the current invention. 
         FIG. 6  illustrates an exemplary diagram for SPS configuration with multiple BWP in accordance with embodiments of the current invention. 
         FIG. 7  illustrates an exemplary flow chart for the time-based active BWP switching in accordance with embodiments of the current invention. 
         FIG. 8  illustrates an exemplary flow chart for the active BWP switching being valid only within the first three OFMD symbols of a subframe or a slot in accordance with embodiments of the current invention. 
         FIG. 9  illustrates an exemplary flow chart for SPS configuration with active BWP switching in accordance with embodiments of the current invention. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to some embodiments of the invention, examples of which are illustrated in the accompanying drawings. 
       FIG. 1  illustrates a system diagram of a wireless network  100  with one or more BWPs configured in accordance with embodiments of the current invention. Wireless communication system  100  includes one or more wireless networks each of the wireless communication network has fixed base infrastructure units, such as receiving wireless communications devices or base unit  102   103 , and  104 , forming wireless networks distributed over a geographical region. The base unit may also be referred to as an access point, an access terminal, a base station, a Node-B, an eNode-B, a gNB, or by other terminology used in the art. Each of the base unit  102 ,  103 , and  104  serves a geographic area. Backhaul connections  113 ,  114  and  115  connect the non-co-located receiving base units, such as  102 ,  103 , and  104 . These backhaul connections can be either ideal or non-ideal 
     A wireless communications device  101  in wireless network  100  is served by base station  102  via uplink  111  and downlink  112 . Other UEs  105 ,  106 ,  107 , and  108  are served by different base stations. UEs  105  and  106  are served by base station  102 . UE  107  is served by base station  104 . UE  108  is served by base station  103 . 
     In one novel aspect, wireless communication network  100  operates with large contiguous radio spectrums. UE  101  while accessing wireless communication network  100 , acquires synchronization information and system information using primary SS anchor. An SS block consists of synchronization signals and physical broadcast channel carries necessary system information for starting initial access procedure. UE RF bandwidth adaptation is supported. For more efficient operation of supporting the bandwidth adaptation, one or more bandwidth part (BWP) candidates with configuration parameters are configured per cell (or carrier). The BWP configuration parameters includes BWP numerology, such as subcarrier spacing and cyclic prefix (CP) length, the frequency location of the BWP and the BWP bandwidth. A BWP may include SS block. UE  101  may be configured with one or more BWPs per cell (or carrier). UE  101  is configured with at least one active DL/UL BWP at any given time. A DL BWP includes at least one control resource (CORESET) for the case of signal active DL/UL BWP at a given time. Each CORESET contains the time-frequency radio resource reserved to accommodate the schedulers for the DL/UL data. UE  101  can be configured with one or more COREETs. A CORESET with a set of candidate locations for the schedulers of system information broadcast, DL broadcast or multi-cast data is a common search space (CSS) CORESET. A CORESET with a set of candidate locations for the schedulers of DL/UL unicast data is a UE-specific search space CORESET. Radio resource management (RRM) measurement is used for the network to manage the radio resources. RRM measurement includes at least reference signal received power (RSRP) and reference signal received quality (RSRQ). 
     The UE supports different BWP configurations. In one example, for paired spectrum, up to four UE-specific RRC configured DL BWPs and up to four UE-specific RRC configured UL BWPs per serving cell is supported. For unpaired spectrum, up to four UE-specific RRC configured DL/UL BWP pairs per serving cell is supported. 
       FIG. 1  further shows simplified block diagrams of wireless device/UE  101  and base station  102  in accordance with the current invention. 
     Base station  102  has an antenna  126 , which transmits and receives radio signals. A RF transceiver module  123 , coupled with the antenna, receives RF signals from antenna  126 , converts them to baseband signals and sends them to processor  122 . RF transceiver  123  also converts received baseband signals from processor  122 , converts them to RF signals, and sends out to antenna  126 . Processor  122  processes the received baseband signals and invokes different functional modules to perform features in base station  102 . Memory  121  stores program instructions and data  124  to control the operations of base station  102 . Base station  102  also includes a set of control modules, such as a wide band manager  181  that configures BWP, CORESET and communicates with UEs to implement the wide band operations. 
     UE  101  has an antenna  135 , which transmits and receives radio signals. A RF transceiver module  134 , coupled with the antenna, receives RF signals from antenna  135 , converts them to baseband signals and sends them to processor  132 . RF transceiver  134  also converts received baseband signals from processor  132 , converts them to RF signals, and sends out to antenna  135 . Processor  132  processes the received baseband signals and invokes different functional modules to perform features in mobile station  101 . Memory  131  stores program instructions and data  136  to control the operations of mobile station  101 . 
     UE  101  also includes a set of control modules that carry out functional tasks. These functions can be implemented in software, firmware and hardware. A BWP timer unit/circuit  191  starts a dedicated BWP timer upon detecting one or more BWP timer starting triggering events and resets the BWP timer upon detecting one or more BWP resetting triggering events. A BWP discontinuous reception (DRX) unit/circuit  192  performs timer-based BWP switching in the DRX mode. A BWP SPS unit/circuit  193  configures SPS for UE with multiple BWPs and activates and releases the SPS upon BWP switching. A BWP detector  194  detects BWP management events including BWP timer triggers. 
     In one novel aspect, a timer-based active BWP switching is provided. A dedicated BWP timer is used independent of the DRX timer. The considerations of the DRX inactivity timer configuration and the timer configuration for the timer-based active BWP switching are very different. The DRX inactivity timer usually requires larger value to reduce the latency of potential DL data packet transmission. The timer for timer-based active BWP switching requires smaller value to maximize UE power saving. Enforcing the two different schemes to share the same timer may defeat their own design purpose and will complicate the designs. Further, from the UE perspective, the added complexity of one new timer is negligible. 
       FIG. 2  illustrates exemplary diagrams of timer-based active BWP switching in accordance to embodiments of the current invention. In one embodiment, the BWP timer is triggered when the UE receives a DCI to switch its active DL BWP from the default BWP to another. In one embodiment, the UE sets an initial BWP as the default BWP. In another embodiment, the UE sets one of the configured BWPs as a default BWP. The setting of the default BWP is based on the higher-layer signaling. In one embodiment, the higher layer signaling is RRC signaling. In another embodiment, the higher layer signaling is MAC CE. The BWP timer is reset upon detecting the timer-resetting condition. In one embodiment, the timer-resetting condition is the UE receiving a DCI to schedule physical down link shared channels (PDSCHs) in the BWP other the default BWP. As illustrated, the UE is configured with multiple BWPs for a cell of the UE. BWP configuration  210  includes a default BWP  211  with a smaller bandwidth and a BWP #2  212  with larger bandwidth. Other similar BWP configurations are also possible for each cell of the UE. At any given time, at least one BWP is active. A default BWP is also configured for the UE. Time slots  201  to  206  is shown as exemplary continuous time slots for the UE. Default BWP  251  is active at slot  201 . At step  221 , a BWP switch command is received in the DCI. In one novel aspect, upon decoding the BWP switch command in the DCI, the UE starts a BWP timer at step  231 . The UE switches to BWP #2  252  at time slot  202 . Before the BWP timer expires, a BWP timer-resetting triggering event is detected and the UE reset the BWP timer at step  232 . In one embodiment, the BWP timer-resetting triggering event is receiving a DCI to schedule PDSCH in the BWP other than the default BWP. The UE is scheduled to continue on BWP #2 at time slot  203 . Similarly, the BWP timer is reset at step  233  upon detecting the DL PDSCH scheduling on BWP #2 for time slot  204 . The UE stays on BWP #2 at time slot  204 . At time slot  205 , there is no more DL data transmission and the BWP timer continues. At the end of time slot  205 , the BWP timer expired at step  234 . In one embodiment, upon detecting the expiration of the BWP timer at step  234 , the UE performs the timer-based BWP switching at step  222 . The UE switches back to default BWP. The UE stays on the default BWP at time slot  206  with bandwidth of  254 . 
     In other similar scenarios, the BWP timer serves to facilitate the BWP switches such that the UE configured with wideband carriers can be more efficient. Other BWP timer triggering events and timer-resetting triggering events can also be configured for the UE. In other embodiments, the UE operates in the DRX mode uses timer-based active BWP switching based on different triggering and resetting events. 
       FIG. 3  illustrates exemplary diagrams for BWP operation with timer-based BWP switching in the DRX mode in accordance with embodiments of the current invention. For the UE without BWP configuration, the UE operates in the DRX mode  310  is configured with a DRX cycle  301 , and a DRX-off period  302 . In the DRX-on period, the UE operates with the bandwidth  303 . At period  311 , the UE detects DL data transfer during DRX-on period and the data transfer continues during period  311 . At the end of period  311 , the DL data transfer ended. The UE is configured with an inactivity timer with a timer value  313 . During the period of  312 , there is no DL data but the UE stays with the bandwidth  303  and monitors the PDCCH. At the end of the inactivity timer  313 , the UE enters DRX-off period again. 
     For UE configured with multiple BWPs, the DRX operation  350  is different. For better power saving gain, the UE assumes the default DL BWP as the active DL BWP by default for DCI monitoring during DRX-on duration. However, it is also beneficial to allow the network to switch a UE&#39;s active DL BWP from the default DL BWP to the one with wider bandwidth to shorten the time for DL data reception when there is DL data scheduling. For active UL BWP indication/switching, it can be indicated by UL scheduling DCI. It is also beneficial to support the timer-based active DL BWP switching to allow faster switching back to the default BWP when there is no data scheduling. The DCI-based DL/UL BWP switching and the timer-based DL/UL BWP switching are supported with the DRX mode. 
     The UE, with multiple BWP operating with DRX, is configured multiple BWPs with a default BWP. The UE also configured with DRX cycle  351  and the DRX-off period  352 . When there is no data transmission, in one embodiment, the UE operates in the default BWP with a bandwidth  353 . During the DRX-on period, the UE receives BWP adaptation command from a higher-layer signaling at step  381 . In one embodiment, the BWP adaptation command is received in the DCI. In another embodiment, the BWP adaptation command is received through the radio resource control (RRC) signaling. Optionally, in one embodiment, the UE starts the BWP timer at step  391 , upon decoding the higher-layer signaling for the BWP adaptation. The UE switches its active BWP to BWP  361  with a bandwidth  354 . In one novel aspect, a separate BWP timer is used together with the DRX timers. During the data transmission, the UE may reset its BWP timer started at step  391 . Upon finishing the data transfer, the UE starts the inactivity timer at step  382 . 
     In another embodiment, instead of triggering the BWP timer at step  391  upon detecting the BWP switching command, the BWP timer is started when the data transfer finished at step  392 . The BWP timer started at step  392  has a timer value  363 , which is smaller than the inactivity timer value  362 . Upon expiration of the BWP timer, the UE performs the timer-based active BWP switching and switches its active BWP back to the default BWP at step  393 . At step  383 , the inactivity timer expired and the UE returns to DRX-off period. 
     In the first embodiment, in the DRX mode, a UE assumes that the default DL BWP is the active DL BWP by default during DRX-on duration if there is no higher-layer configuration supported or signaled from the network to the UE. In second embodiment, in DRX mode, the network signals to a UE by higher-layer signaling, indicating which DL BWP is the active DL BWP by default during DRX-on duration. In one embodiment, the higher-layer signaling is the RRC signaling. In another embodiment, the higher-layer signaling is MAC CE. In third embodiment, in DRX mode, a UE switches its active DL BWP from one to another when it receives a physical-layer signaling for active DL BWP switching during DRX-on duration. In the fourth embodiment, in DRX mode, a UE switches its active UL BWP from one to another when it receives a physical-layer signaling for active UL BWP switching during DRX-on duration. In the fifth embodiment, in DRX mode, a UE switches its active DL BWP from a DL BWP to the default DL BWP when the timer for timer-based active DL BWP switching expires. 
     For unpaired spectrum, such the TDD, due to the linking between the configured DL BWP and the UL BWP, there may be active DL/UL BWP pair indication conflict between the scheduling DCI based and timer-based BWP switching. The linked DL BWP and UL BWP allows the UE to switch from Rx to Tx and vice versa without changing its RF center frequency for short switching time that requires increasing RF hardware cost. Therefore, it is important to resolve the conflict for the paired DL/UL BWP configuration. 
       FIG. 4  illustrates exemplary diagrams for paired DL/UL BWP with timer-based active BWP switching in accordance with embodiments of the current invention. The UE is configured with multiple BWPs with DL/UL BWP pair. The exemplary cell BWP configuration  416  includes a default DL/UL BWP pair  417  and a DL/UL BWP #2 pair  418 . As illustrated, the UE operates at the DL/UL default BWP pair in time slots  401  and  402 . At the beginning of time slot  402 , the UE receives BWP switching command in the DCI at step  451 . In one embodiment, the UE starts the BWP timer, at step  461  upon detecting the triggering event of the BWP switching command. The UE receives DL data transmission with the BWP #2 at time slots  403  and  404 . At step  462 , the UE resets the BWP timer because it receives the DL scheduling. At time slot  405 , the UE transmits UL data with UL BWP #2. At time  406 , the UE receives DL scheduling for DL data to be received on DL BWP #2. Upon receiving the DL scheduling, the UE reset the BWP timer at step  463 . At time slot  407 ,  408  and  409 , the UE stays on BWP #2 while there is no DL or UL data. The BWP timer elapsed and at step  464 , the BWP timer expired. Accordingly, the UE would have switch back to the default BWP for both the DL and UL BWP since the DL and UL are linked BWP pair. A conflict would occur when at time slot  410 , the UE needs to send uplink data and is scheduled to use BWP #2 for the UL. If the UE follows the higher-layer signaling switching the UL to BWP #2 while the DL BWP switched back to the default BWP based on the timer-based active BWP switching, the DL and UL have a conflict. In one embodiment, the UE restarts the timer when it detects PDCCH to schedule PDSCH in the DL/UL BWP pair other than the default DL/UL BWP pair. The UE adds one timer-resetting condition as detecting PDCCH to schedule PUSCH in the DL/UL BWP pair other than the default DL/UL BWP pair. In another embodiment, the UE restarts the timer when it successfully decoding a DCI to schedule one or more PDSCHs in a BWP that is not the default BWP for DL. The UE adds one timer-resetting condition as successfully decoding a DCI to schedule one or more PDSCHs in a BWP that is not the default BWP for DL. In another embodiment, the UE follows the indication of scheduling DCI based active DL/UL BWP pair switching when there is a conflict between the indication of timer-based active DL/UL BWP pair switching and the indication of scheduling DCI based active DL/UL BWP pair switching. In another embodiment, the UE restarts the timer when it successfully decoding a DCI to schedule one or more PUSCHs in a BWP. The UE adds one timer-resetting condition as successfully decoding a DCI to schedule one or more PUSCHs in a BWP. 
     In another embodiment, the UE only decodes the scheduling DCI carrying an indication of active DL or UL BWP switching in a CORESET within the first 3 orthogonal frequency division multiplexing (OFDM) symbols of a subframe or a slot. The BWP switching information outside the first 3 OFDM symbols of a subframe or a slot is ignored. 
       FIG. 5  illustrates exemplary diagrams for the active BWP switching decoding scheme with OFDM symbols in accordance with embodiments of the current invention. The UE is not expected to receive the scheduling DCI carrying an indication of active DL (or UL) BWP switching in a CORESET outside first 3 OFDM symbols of a subframe or a slot. Three exemplary scenarios are shown. Scenario  510  illustrates an 15 Khz subcarrier space (SCS) with the DCI carrying the indication of active BWP switching in the first three OFDM symbols of a subframe or a slot. Scenario  520  illustrates an 15 Khz SCS with the DCI carrying the indication of active BWP switching outside the first three OFDM symbols of a subframe or a slot and the DCI command is ignored. Scenario  530  illustrates an 30 Khz SCS with the DCI carrying the indication of active BWP switching in the first three OFDM symbols of a subframe or a slot. 
     The UE is configured with a default BWP #1 with bandwidth  501  and a BWP #2 with bandwidth  502 . Scenario  510  shows four time slots. The SCS is 15 khz. At the beginning of the second time slot at step  511 , the UE receives active BWP switching DCI at the default BWP #1 to switch to BWP #2. After time  503  of processing time for the DCI command, at step  512 , the UE starts to perform RF tuning and AGC settling for BWP #2 with time  504 . At step  513 , the UE starts to receiving data on PDCCH or PDSCH. From step  511  to  513 , length  519  there are 28 OFDM symbols. The UE starts the new BWP #2 at the start of the subframe or the slot. In this scenario, the UE monitors the first three OFDM symbols for the DCI indication of active BWP switching and upon successfully obtaining the command, the UE switches its BWP accordingly. 
     In scenario  520 , the UE ignores any DCI indication for active BWP switching outside the first three symbols of a subframe or a slot. At step  521 , assuming there is a DCI indication received on BWP #1 for active BWP switching command to BWP #2, the UE would ignore this command. As an example, if the UE performs the command accordingly, the UE needs time  503  to prepare and at step  522  the UE performs the RF tuning and AGC settling. Upon finishing the RF tuning, the UE at step  523  would start to receive data on BWP #2. However, the starting of the BWP #2 does not fall at the beginning of a subframe or a slot. From step  521  to  523 , length  529  there are 28 OFDM symbols. Instead, the BWP #2 starts at the middle of a subframe or a slot. Therefore, to avoid the problem, the DCI indication for active BWP switching outside the first three symbols are ignored. The UE continues to operate on BWP #1. 
     Scenario  530  illustrates a similar success active BWP switching for a 30 Khz SCS whose DCI indication for active BWP switching is within the first three symbol of a subframe or a slot. At step  531 , the UE receives active BWP switching DCI at the default BWP #1 to switch to BWP #2. After time  503  of processing time for the DCI command, at step  532 , the UE starts to perform RF tuning and AGC settling for BWP #2 with time  504 . At step  533 , the UE starts to receiving data on PDCCH or PDSCH. From step  531  to  533 , length  539  there are 56 OFDM symbols. The UE starts the new BWP #2 at the start of the subframe or the slot. In this scenario, the UE monitors the first three OFDM symbols for the DCI indication of active BWP switching and upon successfully obtaining the command, the UE switches its BWP accordingly. 
     In another novel aspect, when a semi-persistent scheduling (SPS) is configured for a serving cell, each configured DL/UL BWP also includes SPS configuration. 
       FIG. 6  illustrates an exemplary diagram for SPS configuration with multiple BWP in accordance with embodiments of the current invention. Since SPS is mainly meant for smaller data packet, the configured or activated SPS opportunities (either DL or UL) should be able to be accommodated in all configured (either DL or UL) BWPs. For SPS with no DCI-based activation/release, the configured SPS opportunities should remain valid after a UE switches its active DL (UL) BWP from one to another by either scheduling DCI-based or timer-based scheme. In one embodiment, only the SPS opportunities in its active DL (UL) BWP are activated to the UE. For SPS with DCI-based activation/release, the activated SPS opportunities should be assumed to be released by default after a UE switches its active DL (UL) BWP from one to another by either scheduling DCI-based or timer-based scheme. At step  601 , the serving cell of the UE is configured with SPS. At step  602 , each BWP configured is also configured with SPS accordingly. At step  603 , the UE receives BWP switching command. At step  611 , the UE determines if the BWP switching command is DCI-based BWP activation or release. If step  611  determines no, the UE moves to step  621 , the configured SPS remains valid by either scheduling DCI-based or timer-based. In one embodiment, only the SPS opportunities in its active DL (UL) BWP are activated to the UE. If step  611  determines yes, the configured SPS is released. 
       FIG. 7  illustrates an exemplary flow chart for the time-based active BWP switching in accordance with embodiments of the current invention. At step  701 , the UE configures a plurality of BWPs in a wireless network, wherein a BWP includes a plurality of contiguous PRBs, and wherein the UE sets an initial BWP or one of the configured BWPs as a default BWP based on a higher-layer configuration. At step  702 , the UE starts a BWP timer upon detecting one or more BWP timer starting triggering events. At step  703 , the UE resets the BWP timer upon detecting one or more BWP timer resetting triggering events. At step  704 , the UE switches to the default BWP upon expiration of the BWP timer. 
       FIG. 8  illustrates an exemplary flow chart for the active BWP switching being valid only within the first three OFMD symbols of a subframe or a slot in accordance with embodiments of the current invention. At step  801 , the UE configuring a plurality of BWPs in a wireless network, wherein a BWP includes a plurality of contiguous PRBs. At step  802 , the UE receives DL DCI, wherein the DCI is carried in a DL OFDM CORESET. At step  803 , the UE obtains indication of active BWP switching command by decoding first three OFDM symbols of a slot in a CORSET. At step  804 , the UE ignores indication of active BWP switching command outside the first three OFDM symbols of a slot. 
       FIG. 9  illustrates an exemplary flow chart for SPS configuration with active BWP switching in accordance with embodiments of the current invention. At step  901 , the UE configures a plurality of BWPs in a wireless network, wherein a BWP includes a plurality of contiguous PRBs. At step  902 , the UE configures a SPS in a serving cell of the UE. At step  903 , the UE configures SPS opportunities in all the BWPs of the UE based on the SPS configuration for the serving cell. 
     Although the present invention has been described in connection with certain specific embodiments for instructional purposes, the present invention is not limited thereto. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.