Patent Description:
<CIT> discloses a beamforming technique according to which the UE firstly receives the configuration information from an eNB and then adjusts its beam sweep configuration to be compatible with this base station and finally performs a beam sweep with said base station.

<NPL>, discloses the amount of beams per sweep and amount of sweeping blocks should be flexible in the sense that they account for both UE complexity as well as for the BS needs in terms of spatial coverage.

A method and apparatus for handling beamforming in a wireless communication system are disclosed and defined in independent claim <NUM> (method - UE), claim <NUM> (method - network), claim <NUM> (device - UE) and claim <NUM> (device - network). Preferred embodiments thereof are defined in the dependent claims, respectively. The invention is defined in particular by the essential features prominently marked by the words "according to an essential aspect of the present invention". Other embodiments and/or examples not falling under the claims and not comprising these features are not part of the claimed invention but are useful for understanding the invention.

The exemplary wireless communication systems and devices described below employ a wireless communication system, supporting a broadcast service. Wireless communication systems are widely deployed to provide various types of communication such as voice, data, and so on. These systems may be based on code division multiple access (CDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), 3GPP LTE (Long Term Evolution) wireless access, 3GPP LTE-A or LTE-Advanced (Long Term Evolution Advanced), 3GPP2 UMB (Ultra Mobile Broadband), WiMax, or some other modulation techniques.

In particular, the exemplary wireless communication systems devices described below may be designed to support one or more standards such as the standard offered by a consortium named "3rd Generation Partnership Project" referred to herein as 3GPP, including: <NPL>; <NPL>; <NPL>; <NPL>; <NPL>"; <NPL>; 3GPP RAN2#<NUM> meeting minute; <NPL>; <NPL>; <NPL>; <NPL>; <NPL>; <NPL>.

<FIG> shows a multiple access wireless communication system according to one embodiment of the invention. An access network <NUM> (AN) includes multiple antenna groups, one including <NUM> and <NUM>, another including <NUM> and <NUM>, and an additional including <NUM> and <NUM>. In <FIG>, only two antennas are shown for each antenna group, however, more or fewer antennas may be utilized for each antenna group. Access terminal <NUM> (AT) is in communication with antennas <NUM> and <NUM>, where antennas <NUM> and <NUM> transmit information to access terminal <NUM> over forward link <NUM> and receive information from access terminal <NUM> over reverse link <NUM>. Access terminal (AT) <NUM> is in communication with antennas <NUM> and <NUM>, where antennas <NUM> and <NUM> transmit information to access terminal (AT) <NUM> over forward link <NUM> and receive information from access terminal (AT) <NUM> over reverse link <NUM>. In a FDD system, communication links <NUM>, <NUM>, <NUM> and <NUM> may use different frequency for communication. For example, forward link <NUM> may use a different frequency then that used by reverse link <NUM>.

In communication over forward links <NUM> and <NUM>, the transmitting antennas of access network <NUM> may utilize beamforming in order to improve the signal-to-noise ratio of forward links for the different access terminals <NUM> and <NUM>. Also, an access network using beamforming to transmit to access terminals scattered randomly through its coverage causes less interference to access terminals in neighboring cells than an access network transmitting through a single antenna to all its access terminals.

An access network (AN) may be a fixed station or base station used for communicating with the terminals and may also be referred to as an access point, a Node B, a base station, an enhanced base station, an evolved Node B (eNB), or some other terminology. An access terminal (AT) may also be called user equipment (UE), a wireless communication device, terminal, access terminal or some other terminology.

<FIG> is a simplified block diagram of an embodiment of a transmitter system <NUM> (also known as the access network) and a receiver system <NUM> (also known as access terminal (AT) or user equipment (UE)) in a MIMO system <NUM>. At the transmitter system <NUM>, traffic data for a number of data streams is provided from a data source <NUM> to a transmit (TX) data processor <NUM>.

Preferably, each data stream is transmitted over a respective transmit antenna. TX data processor <NUM> formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot data using OFDM techniques. The pilot data is typically a known data pattern that is processed in a known manner and may be used at the receiver system to estimate the channel response. The multiplexed pilot and coded data for each data stream is then modulated (i.e., symbol mapped) based on a particular modulation scheme (e.g., BPSK, QPSK, M-PSK, or M-QAM) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream may be determined by instructions performed by processor <NUM>.

At receiver system <NUM>, the transmitted modulated signals are received by NR antennas 252a through 252r and the received signal from each antenna <NUM> is provided to a respective receiver (RCVR) 254a through 254r. Each receiver <NUM> conditions (e.g., filters, amplifies, and downconverts) a respective received signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding "received" symbol stream.

Turning to <FIG>, this figure shows an alternative simplified functional block diagram of a communication device according to one embodiment of the invention. As shown in <FIG>, the communication device <NUM> in a wireless communication system can be utilized for realizing the UEs (or ATs) <NUM> and <NUM> in <FIG> or the base station (or AN) <NUM> in <FIG>, and the wireless communications system is preferably the LTE system. The communication device <NUM> may include an input device <NUM>, an output device <NUM>, a control circuit <NUM>, a central processing unit (CPU) <NUM>, a memory <NUM>, a program code <NUM>, and a transceiver <NUM>. The control circuit <NUM> executes the program code <NUM> in the memory <NUM> through the CPU <NUM>, thereby controlling an operation of the communications device <NUM>. The communications device <NUM> can receive signals input by a user through the input device <NUM>, such as a keyboard or keypad, and can output images and sounds through the output device <NUM>, such as a monitor or speakers. The transceiver <NUM> is used to receive and transmit wireless signals, delivering received signals to the control circuit <NUM>, and outputting signals generated by the control circuit <NUM> wirelessly. The communication device <NUM> in a wireless communication system can also be utilized for realizing the AN <NUM> in <FIG>.

<FIG> is a simplified block diagram of the program code <NUM> shown in <FIG> in accordance with one embodiment of the invention. In this embodiment, the program code <NUM> includes an application layer <NUM>, a Layer <NUM> portion <NUM>, and a Layer <NUM> portion <NUM>, and is coupled to a Layer <NUM> portion <NUM>. The Layer <NUM> portion <NUM> generally performs radio resource control. The Layer <NUM> portion <NUM> generally performs link control. The Layer <NUM> portion <NUM> generally performs physical connections.

3GPP standardization activities on next generation (i.e. <NUM>) access technology have been launched since March <NUM>. The next generation access technology aims to support the following three families of usage scenarios for satisfying both the urgent market needs and the more long-term requirements set forth by the ITU-R IMT-<NUM> as follows:.

An objective of the <NUM> study item on new radio access technology is to identify and develop technology components needed for new radio systems which should be able to use any spectrum band ranging at least up to <NUM>. Supporting carrier frequencies up to <NUM> brings a number of challenges in the area of radio propagation. As the carrier frequency increases, the path loss also increases.

Based on 3GPP R2-<NUM>, in lower frequency bands (e. current LTE bands < <NUM>) the required cell coverage may be provided by forming a wide sector beam for transmitting downlink common channels. However, utilizing wide sector beam on higher frequencies (>> <NUM>), the cell coverage is reduced with same antenna gain. Thus, in order to provide required cell coverage on higher frequency bands, higher antenna gain is needed to compensate the increased path loss. To increase the antenna gain over a wide sector beam, larger antenna arrays (e.g., number of antenna elements ranging from tens to hundreds) are used to form high gain beams.

As a consequence, the high gain beams are narrow compared to a wide sector beam so multiple beams for transmitting downlink common channels are needed to cover the required cell area. The number of concurrent high gain beams that access point is able to form may be limited by the cost and complexity of the utilized transceiver architecture. In practice, on higher frequencies, the number of concurrent high gain beams is much less than the total number of beams required to cover the cell area. In other words, the access point is able to cover only part of the cell area by using a subset of beams at any given time.

Based on 3GPP R2-<NUM>, beamforming is a signal processing technique used in antenna arrays for directional signal transmission/reception. With beamforming, a beam can be formed by combining elements in a phased array of antennas in such a way that signals at particular angles experience constructive interference while others experience destructive interference. Different beams can be utilized simultaneously using multiple arrays of antennas.

Based on 3GPP R2-<NUM> and as shown in <FIG> (which is a reproduction of <FIG> of 3GPP R2-<NUM>), an eNB may have multiple TRPs (either centralized or distributed). Each TRP can form multiple beams. The number of beams and the number of simultaneous beams in the time/frequency domain depend on the number of antenna array elements and the RF (Radio Frequency) at the TRP.

Potential mobility type for NR (New Radio) Access Technology can be listed as follows:.

Based on 3GPP R2-<NUM>, reliability of a system purely relying on beamforming and operating in higher frequencies might be challenging, since the coverage might be more sensitive to both time and space variations. As a consequence, the SINR of the narrow link can drop much quicker than in the case of LTE.

Using antenna arrays at access nodes with the number of elements in the hundreds, fairly regular grid-of-beams coverage patterns with tens or hundreds of candidate beams per node may be created. The coverage area of an individual beam from such array may be small, down to the order of some tens of meters in width. As a consequence, channel quality outside the current serving beam area would degrade quicker than in the case of wide area coverage, as provided by LTE.

Based on 3GPP R3-<NUM>, the scenarios illustrated in <FIG> and <FIG> should be considered for support by the NR radio network architecture.

Based on 3GPP R2-<NUM>, the following scenarios in terms of cell layout for standalone NR are captured to be studied:.

Based on 3GPP RAN2#<NUM> meeting minutes, <NUM> NR eNB corresponds to <NUM> or many TRPs. Two levels of network controlled mobility are as follows:.

Based on R2-<NUM>, in <NUM>, the principle of <NUM>-level mobility handling may possibly be kept as follows:.

<NUM> systems are expected to rely more heavily on "beam based mobility" to handle UE mobility, in addition to regular handover based UE mobility. Technologies like MIMO (Multiple Input Multiple Output), fronthauling, C-RAN (Cloud Radio Access Network), and NFV (Network Function Virtualization) will allow the coverage area controlled by one "<NUM> Node" to grow, thereby increasing the possibilities for beam level management and reducing the need for cell level mobility. All mobility within the coverage area of one <NUM> node could in theory be handled based on beam level management, which would leave handovers only to be used for mobility to the coverage area of another <NUM> Node.

<FIG> show some example of the concept of a cell in <NUM> NR. <FIG> (a reproduction of a diagram in <FIG> of 3GPP R2-<NUM>) shows a deployment with single TRP cell. <FIG> (a reproduction of a diagram in <FIG> of 3GPP R2-<NUM>) shows a deployment with multiple TRP cell. <FIG> (a reproduction of <FIG> of 3GPP R2-<NUM>) shows one <NUM> cell comprising a <NUM> node with multiple TRPs. <FIG> (a reproduction of <FIG> of 3GPP R2-<NUM>) shows a comparison between a LTE cell and a NR cell.

Apart from the handover based on RRM (Radio Resource Management) measurement, a <NUM> UE should be able to adapt the serving beam to maintain <NUM> connectivity subject to beam quality fluctuation or UE intra-cell mobility. In order to do so, <NUM> Node-B and UE should be able to track and change the serving beam properly (called beam tracking hereafter).

Based on 3GPP R2-<NUM>, the design of the new RAT must be forward compatible with Phase II specification and beyond. For forward compatible consideration, and to avoid duplicated discussion, it does not expect different low layer designs for standalone NR and the NR used for tight interworking, and prefer the lower layer of standalone NR should be same as the one used for the tight interworking.

The following terminologies and assumption may be used hereafter.

The following assumptions for network side may be used hereafter.

The following assumptions for UE side may be used hereafter:.

Based on 3GPP R2-<NUM>, to use beamforming in both eNB and UE sides, practically, antenna gain by beamforming in eNB is considered about <NUM> to <NUM> dBi and the antenna gain of UE is considered about <NUM> to <NUM> dBi. <FIG> (a reproduction of <FIG> of 3GPP R2-<NUM>) illustrates gain compensation by beamforming.

From the perspective of SINR (Signal to Interference Plus Noise Ratio), sharp beamforming reduces interference power from neighbor interferers, i.e., neighbor eNBs in downlink case or other UEs connected to neighbor eNBs. In TX (Transmission) beamforming case, only interference from other TXs whose current beam points the same direction to the RX will be the "effective" interference. The "effective" interference means the interference power is higher than the effective noise power. In RX (Reception) beamforming case, only interference from other TXs whose beam direction is the same to the UE's current RX beam direction will be the effective interference. <FIG> (a reproduction of <FIG> of 3GPP R2-<NUM>) illustrates weakened interference by beamforming.

After a UE powers on, the UE needs to find a cell to camp on. Then, the UE may initiate a connection establishment to network by itself for registration and/or data transmission. Besides, network could also request the UE to initiate a connection establishment to the network via paging, e.g., in order to transmit DL (Downlink) data to the UE.

A case of initial access may have the following steps:.

<FIG> illustrates an example of a flow chart for initial access.

3GPP R1-<NUM> proposed to concentrate sweeping common control plane functionality into specific subframes, called as sweeping subframes. The common control signaling to be transmitted in sweeping subframe includes synchronization signal (DL), reference signal (DL), system information (DL), random access channel (UL), etc. <FIG> (a reproduction of <FIG> of 3GPP R1-<NUM>) illustrates the principle of sweeping subframe.

One of the main use cases of downlink sweeping is downlink discovery signaling, which comprises for instance signals for cell search, time and frequency synchronization acquisition, essential system information signalling and cell/beam measurements (e.g., RRM measurements).

For UL (Uplink) PRACH (Physical Random Access Channel), the high level idea is to utilize BS beam reciprocity and enable a UE to transmit PRACH preamble when a BS is receiving using beam(s) with high array gain towards the transmitting UE. That means the PRACH resources are associated with the BS beams which are advertised periodically through DL discovery signalling, which conveys beam specific reference signals. <FIG> (a reproduction of <FIG> of 3GPP R1-<NUM>) illustrates the association between BS beams and PRACH resources.

Since high gain beams are narrow and the number of concurrent high gain beams that can be formed may depend on cost and complexity of the utilized transceiver architecture, beam sweeping is needed for a number of times, e.g., beam sweeping number, to cover all possible directions for transmission and/or reception. For example, in <FIG>, the TRP takes <NUM> time intervals to cover all directions and <NUM> beams are generated at each time interval by this TRP.

Signaling for transmission and/or reception, which needs to cover the whole cell coverage by beam sweeping, may include synchronization signal(s), reference signal(s), system information, paging, signal to initiate random access procedure, signals of random access procedure (e.g., random access preamble, random access response, contention resolution), signal for DL/UL scheduling, and/or etc. For downlink signaling, beam sweeping is performed by a TRP for transmission and/or by a UE for reception. For uplink signaling, beam sweeping is performed by a UE for transmission and/or by a TRP for reception.

Based on beam sweeping number of a cell or a TRP and possibly some other parameter(s), the UE accessing the cell or connecting to the TRP could understand the timing where the TRP is transmitting or receiving the signaling. If the UE does not know the beam sweep number, the UE does not know whether to receive or transmit the signaling in a specific time interval. For example, since the UE cannot know whether the signaling is not transmitted by network or is not received due to bad radio condition, the UE may keep measuring reference signal or monitoring paging in time interval(s) when the signaling is not transmitted by the TRP. Or the UE may keep transmitting signal for random access procedure in time interval(s) when the TRP would not receive. Power consumption is increased, and derivation of measurement results may be incorrect (e.g., not reflecting the actual radio condition).

One possible way is to fix the beam sweeping number of the signaling. However, beam sweeping number could depend on capability of network device(s). Fixing the beam sweeping number would limit implementation of network vendors as well as limit scheduling flexibility. Alternatively, the UE should be aware of beamforming capability of the TRP or the cell.

A method to indicate the beam sweeping number to the UE could be considered. The way to indicate the beam sweeping number could be explicit or implicit. The beam sweeping number could be indicated by one or more of the following signaling: (i) synchronization signal(s), (ii) reference signal(s), (iii) system information, and/or (iv) paging. The system information, e.g. master information block (MIB) or primary system information, is broadcasted. The beam sweeping number could be applied to some or all of the signals/signaling requiring beam sweeping in downlink and/or uplink.

For implicit indication, different transmission patterns of the signaling, e.g. synchronization signal(s) or reference signal(s), could be defined corresponding to different beam sweeping number. The patterns could be differentiated by different transmitting timing or frequency resources. Then, the UE could know the beam sweeping number by detecting which pattern is used by a TRP (or a cell). For explicit indication, the beam sweeping number could be derived from information included in the signaling. N bits are needed to signal <NUM>N possible values.

Before the UE acquires the beam sweeping number, if the UE needs to acquire a signaling where beam sweeping is applied, the UE could assume a default beam sweeping number for the signaling. For example, it is assumed that beam sweeping number is indicated by system information. If the UE needs to receive reference signal(s) before acquiring system information, the UE receives the reference signal(s) based on the default beam sweeping number. Furthermore, the UE receives signaling based on the beam sweeping number indicated by system information after the beam sweeping number is acquired.

In another aspect, if interworking (e.g., via dual connectivity) between different RATs or between cell(s) using beam sweeping and cell(s) not using beam sweeping is assumed, a UE could connect to a primary cell (e.g., a LTE cell or a cell not using beam sweeping), and connect to one or more secondary cells at the same time. The beam sweeping number of the secondary cell(s) could be indicated via the primary cell, e.g., included in the configuration to add the secondary cell as a serving cell of the UE. Then, the beam sweeping number of a cell could be known before connecting to the cell.

On the other hand, since it is up to network implementation whether beam sweeping is needed (e.g., a cell in lower frequency band may also use beamforming or beam sweeping to increase coverage, or digital beamforming does not need beam sweeping), the UE may need to know whether a TRP or a cell uses beam sweeping or not in order to decide timing for reception and/or transmission. Similarly, the UE may need to know whether a TRP or a cell uses beamforming or not.

The above method(s) could explicitly or implicitly indicate whether a TRP or a cell uses beam sweeping. Similarly, the above method(s) could explicitly or implicitly indicate whether a TRP or a cell uses beamforming or not. Alternatively, beam sweeping number could be used to inform the UE whether beam sweeping is used by the cell or the TRP. Similarly, beam sweeping number could be used to inform the UE whether beamforming is used by the cell or the TRP.

For example, the absence of the beam sweeping number information or the beam sweeping number equals to zero or one may be used to represent that beam sweeping is not used.

Similarly, the absence of the beam sweeping number information or the beam sweeping number equals to zero or one may be used to represent that beamforming is not used.

From the point of view of a UE, the beam sweeping number is more like a scaling number indicating scaling level of a signaling transmission in time domain. According to an essential aspect of the present invention, the signaled beam sweeping number is considered as a number of how many time intervals the UE needs to monitor (or transmit) a specific signal in a time period. The UE determines to monitor (or transmit) the specific signal for how many and in which time intervals (at least) based on the beam sweeping number. The time intervals may be continuous or interleave. Other parameters may also be provided to the UE for the determination. For example, if paging is transmitted every x TTIs (Transmission Time Intervals) and the signaled beam sweeping number is y, the UE monitors paging for y TTIs every x TTIs at the paging occasion of the UE.

In addition, since it is up to network implementation whether UE beamforming is supported by network and could be used by UE for transmission and/or reception, the UE also needs to know whether a TRP or a cell supports or enables UE beamforming in order to decide timing for reception and/or transmission. The above method(s) could explicitly or implicitly indicate whether a TRP or a cell supports or enables UE beamforming. The UE also needs to know the number of beams to be generated concurrently by UE. The above method(s) could explicitly or implicitly indicate the number of beams to be generated by UE.

In a cell with multiple TRPs where each TRP operates with multiple beams, it is possible that not all TRPs in the cell have the same capability with respect to beamforming, e.g., total number of beams, maximum number of beams that can be generated concurrently, minimum beam sweeping number, or etc. As mentioned above, a signal of a cell may be transmitted by beam sweeping in order to cover whole cell coverage. The signal may include synchronization signal(s), reference signal(s), system information, and/or paging. If the number of beams which a TRP can generate concurrently is less than total number of beams in the TRP, and if at least two TRPs of the cell have different total numbers of beams, it would be beneficial to share a same beam sweeping number among all TRPs of the cell so that each TRP of the cell could transmit the same signal to UEs in the cell at multiple time intervals in beam sweeping manner with the same beam sweeping number.

Keeping beam sweeping number aligned among TRPs in the same cell can reduce overhead of signaling the beam sweeping number. If beam sweeping number of TRPs in a cell is aligned or less than the beam sweeping number indicated to the UE, the cell does not need to signal different beam sweeping numbers for different TRPs, or the UE does not need to reacquire the beam sweeping number when changing TRP within a cell. In other words, the actual beam sweeping number performed by TRPs in the cell is, according to an essential aspect of the present invention, less or equal to the indicated beam sweeping number associated with the cell. In addition, some degree of flexibility can still be reached since beam sweeping number in different cells can be different.

The beam sweeping number could be the number of time intervals to sweep beams in all directions once for transmission and/or reception. The beam sweeping number could be indicated to UEs to be served by the cell. Actual number of beam sweeping performed by a TRP should not be larger than (e.g., could be less than or equal to) the indicated beam sweeping number. A same number of beams could be generated by the TRP at multiple time intervals for transmitting a signal.

The above information (e.g., beam sweeping number, usage of beam sweeping by network, enabling UE beamforming, etc.) could be indicated by the same signaling or different signaling. Beam sweeping is performed to provide whole coverage of the cell or the TRPs. The number of beam sweeping is determined based on the maximum number of beams that can be generated concurrently by the TRP and/or other TRP of the cell, and the total number of beams in the TRP and/or other TRP of the cell. The time interval may be a unit on time domain (e.g., TTI, subframe, or symbol).

<FIG> is a flow chart <NUM> according to one exemplary embodiment from the perspective of a network. In step <NUM>, the network forms a cell that comprises at least two network nodes, wherein a first signal is transmitted by every network node of the cell using beam sweeping limited by a same number of beam sweeping, and wherein the two network nodes have different beamforming capabilities.

Referring back to <FIG> and <FIG>, the device <NUM> includes a program code <NUM> stored in the memory <NUM>. The CPU <NUM> could execute program code <NUM> to form a cell that comprises at least two network nodes, wherein a first signal is transmitted by every network node of the cell using beam sweeping limited by a same number of beam sweeping, and wherein the two network nodes have different beamforming capabilities. Furthermore, the CPU <NUM> can execute the program code <NUM> to perform all of the above-described actions and steps or others described herein.

<FIG> is a flow chart <NUM> according to an essential aspect of the present invention, from the perspective of a network. In step <NUM>, the network forms a cell that comprises at least two network nodes, wherein a same number of beam sweeping is indicated by a second signal transmitted by every network node of the cell, and wherein the two network nodes have different beamforming capabilities.

Referring back to <FIG> and <FIG>, the device <NUM> includes a program code <NUM> stored in the memory <NUM>. The CPU <NUM> could execute program code <NUM> to form a cell that comprises at least two network nodes, wherein a same number of beam sweeping is indicated by a second signal transmitted by every network node of the cell, and wherein the two network nodes have different beamforming capabilities. Furthermore, the CPU <NUM> can execute the program code <NUM> to perform all of the above-described actions and steps or others described herein.

<FIG> is a flow chart <NUM> according to one exemplary embodiment from the perspective of a network. In step <NUM>, the network transmits a first signal from every network nodes of a cell, wherein the first signal is transmitted using beam sweeping limited by a same number of beam sweeping; and at least two network nodes of the cell have different beamforming capabilities. Referring back to <FIG> and <FIG> the device <NUM> includes a program code <NUM> stored in the memory <NUM>. The CPU <NUM> could execute program code <NUM> to transmit a first signal from every network nodes of a cell, wherein the first signal is transmitted using beam sweeping limited by a same number of beam sweeping; and at least two network nodes of the cell have different beamforming capabilities. Furthermore, the CPU <NUM> can execute the program code <NUM> to perform all of the above-described actions and steps or others described herein.

<FIG> is a flow chart <NUM> according to an essential aspect of the present invention, from the perspective of a UE. Step <NUM> includes receiving a second signal indicating a number of beam sweeping from a cell, wherein there are multiple network nodes in the cell and at least two network nodes of the cell have different beamforming capabilities. Step <NUM> includes receiving a first signal from any network node of the cell at multiple time intervals based on the number of beam sweeping. The first signal is transmitted by any network node of the cell using beam sweeping.

Referring back to <FIG> and <FIG>, in one exemplary embodiment of a UE, the device <NUM> includes a program code <NUM> stored in the memory <NUM>. The CPU <NUM> could execute program code <NUM> to enable the UE (i) to receive a second signal indicating a number of beam sweeping from a cell, wherein there are multiple network nodes in the cell and at least two network nodes of the cell have different beamforming capabilities, and (ii) to receive a first signal from any network node of the cell at multiple time intervals based on the number of beam sweeping. Furthermore, the CPU <NUM> can execute the program code <NUM> to perform all of the above-described actions and steps or others described herein.

<FIG> is a flow chart <NUM> according to one exemplary embodiment from the perspective of a network. In step <NUM>, the network transmits a second signal indicating a same number of beam sweeping from every network node of a cell, wherein there are multiple network nodes in the cell and at least two network nodes of the cell have different beamforming capabilities.

Referring back to <FIG> and <FIG> the device <NUM> includes a program code <NUM> stored in the memory <NUM>. The CPU <NUM> could execute program code <NUM> to transmit a second signal indicating a same number of beam sweeping from every network node of a cell, wherein there are multiple network nodes in the cell and at least two network nodes of the cell have different beamforming capabilities. Furthermore, the CPU <NUM> can execute the program code <NUM> to perform all of the above-described actions and steps or others described herein.

<FIG> is a flow chart <NUM> according to one exemplary embodiment from the perspective of a network node. In step <NUM>, the network node of a cell transmits a first signal using beam sweeping limited by a number of beam sweeping, wherein the number of beam sweeping is the same for every TRP of the cell, and a first network node and a second network node of the cell have different beamforming capabilities.

Referring back to <FIG> and <FIG> the device <NUM> includes a program code <NUM> stored in the memory <NUM>. The CPU <NUM> could execute program code <NUM> to transmit a first signal using beam sweeping limited by a number of beam sweeping, wherein the number of beam sweeping is the same for every TRP of the cell, and a first network node and a second network node of the cell have different beamforming capabilities. Furthermore, the CPU <NUM> can execute the program code <NUM> to perform all of the above-described actions and steps or others described herein.

<FIG> is a flow chart <NUM> according to one exemplary embodiment from the perspective of a network node. In step <NUM>, the network node of a cell transmits a second signal indicating a number of beam sweeping, wherein the number of beam sweeping is the same as that indicated by every network node of the cell, and a first network node and a second network node of the cell have different beamforming capabilities.

Referring back to <FIG> and <FIG> the device <NUM> includes a program code <NUM> stored in the memory <NUM>. The CPU <NUM> could execute program code <NUM> to transmit a second signal indicating a number of beam sweeping, wherein the number of beam sweeping is the same as that indicated by every network node of the cell, and a first network node and a second network node of the cell have different beamforming capabilities. Furthermore, the CPU <NUM> can execute the program code <NUM> to perform all of the above-described actions and steps or others described herein.

In the context of the embodiments disclosed in <FIG> and discussed above, preferably, the network node (e.g. the first network node and/or the second network node) could operate with multiple beams. Each network node of the cell could operate with multiple beams. The number of beams that the network node can generate concurrently is less than total number of beams in the network node.

Preferably, the beamforming capability could include a total number of beams, a number of beams that can be generated concurrently, and/or a beam sweeping number. A same number of beams could be generated by the network node for transmitting the first signal or the second signal, or by each network node of the cell for transmitting the first signal or the second signal.

Preferably, the first signal and/or the second signal could be transmitted at multiple time intervals using beam sweeping. Preferably, the first signal and/or the second signal could be a synchronization signal. Alternatively, the first signal and/or the second signal could be a reference signal. Alternatively, the first signal and/or the second signal could be a discovery signal. Alternatively, the first signal and/or the second signal could comprise system information. Alternatively, the first signal and/or the second signal could comprise paging. The first signal or the second signal could be transmitted via a channel. Preferably, the channel could be used to deliver synchronization signals. Alternatively, the channel could be used to deliver reference signals. Alternatively, the channel could be used to deliver discovery signals. Alternatively, the channel could be used to deliver system information. Alternatively, the channel could be used to deliver paging.

Preferably, the time interval could be a transmission time interval (TTI), a subframe, a symbol, or a unit on time domain.

Preferably, the beam sweeping could be performed to provide whole coverage of the cell or the network nodes. The number of beam sweeping could be a number of time intervals used to cover whole coverage of the cell or the network nodes, or a number of subset of beams used to cover whole coverage of the cell or the network nodes. The number of beam sweeping could be determined based on a number of beams that can be generated concurrently by a network node and total number of beams in the network node, or a number of beams that can be generated concurrently by other network node of the cell and total number of beams in other network node of the cell. The number of beam sweeping is indicated to UEs to be served by the cell. The number of beams that can be generated concurrently could be a number of beams that can be generated in a same time interval.

Preferably, the beam sweeping limited by the number of beam sweeping comprises that the beam sweeping is performed with a number of times no larger than the number of beam sweeping in a period of time, equal to the number of beam sweeping in a period of time, or less than the number of beam sweeping in a period of time.

Preferably, the network node may not able to transmit the signal with multiple beams to cover whole coverage of the network node in one time interval. Furthermore, the network node could be a TRP, a base station, or a <NUM> node. The signal comprises a common signal.

Preferably, transmitting the first signal using beam sweeping means to transmit the same first signal using different subset of beams in different time intervals during a period of time.

Based on above method(s) and/or embodiment(s), signaling overhead of beam sweeping number can be reduced within a cell while different number of beam sweeping may still be used.

Various aspects of the disclosure have been described above. It should be apparent that the teachings herein may be embodied in a wide variety of forms and that any specific structure, function, or both being disclosed herein is merely representative. Based on the teachings herein one skilled in the art should appreciate that an aspect disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. As an example of some of the above concepts, in some aspects concurrent channels may be established based on pulse repetition frequencies. In some aspects concurrent channels may be established based on pulse position or offsets. In some aspects concurrent channels may be established based on time hopping sequences. In some aspects concurrent channels may be established based on pulse repetition frequencies, pulse positions or offsets, and time hopping sequences.

Those of skill would further appreciate that the various illustrative logical blocks, modules, processors, means, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two, which may be designed using source coding or some other technique), various forms of program or design code incorporating instructions (which may be referred to herein, for convenience, as "software" or a "software module"), or combinations of both. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure, as defined by the appended claims.

It is understood that any specific order or hierarchy of steps in any disclosed process is an example of a sample approach. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged while remaining within the scope of the present disclosure, as defined by the appended claims. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

Claim 1:
A method of a UE (User Equipment), comprising:
receiving (<NUM>), from every network node of a cell, a second signal indicating a same first network beam sweeping number associated with the cell, wherein the first network beam sweeping number is to be used by the UE for receiving a first signal from any network node of the cell, wherein there are multiple network nodes in the cell and at least two network nodes of the cell have different beamforming capabilities, and wherein a beamforming capability of a network node of the cell comprises at least a total number of beams, and actual network beam sweeping numbers performed by the multiple network nodes are less than or equal to the first network beam sweeping number,
wherein:
the first network beam sweeping number is a number of times needed for sweeping beams in all possible directions once for transmission of a signal;
and the method further comprises receiving (<NUM>) the first signal from any network node of the cell at multiple time intervals, wherein the multiple time intervals are determined based on the received first network beam sweeping number.