Patent Description:
Atmospheric ducting is a mode of propagation of electromagnetic radiation, usually in lower layers of the Earth's atmosphere, where the waves are bent by atmospheric refraction. In case of atmospheric ducting, a downlink signal of a network device (for example, an Evolved NodeB) may degrade too little to be ignored by a remote network device (for example, another Evolved NodeB). In this case, remote interference between network devices occurs.

<CIT> discloses a far-end interference detection method and a far-end interference detection device based on TD-LTE system. <CIT> discloses method and apparatus for positioning an interference source.

The present disclosure provide methods, devices, apparatuses, a computer program product and a computer readable storage medium for signal source identification and determination.

In a first aspect, there is provided a method for identifying a signal source. The method comprises transmitting, from a device, at least one unit sequence to a further device, wherein a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies the device in the plurality of devices.

In a second aspect, there is provided a method for determining a signal source. The method comprises in response to detecting a signal at a device, identifying at least one unit sequence from the signal, wherein a bandwidth of each unit sequence is a common divisor of overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies a further device transmitting the signal; and determining, based on the at least one unit sequence, the further device from the plurality of devices.

In a third aspect, there is provided a device. The device comprises at least one processor and at least one memory including computer program codes. The at least one memory and the computer program codes are configured to, with the at least one processor, cause the device to transmit at least one unit sequence to a further device, wherein a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies the device in the plurality of devices.

In a fourth aspect, there is provided a device. The device comprises at least one processor and at least one memory including computer program codes. The at least one memory and the computer program codes are configured to, with the at least one processor, cause the device to in response to detecting a signal, identify at least one unit sequence from the signal, wherein a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies a further device transmitting the signal; and determine, based on the at least one unit sequence, the further device from the plurality of devices.

In a fifth aspect, there is provided an apparatus. The apparatus comprises means for transmitting, from a device, at least one unit sequence to a further device, wherein a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies the device in the plurality of devices.

In an sixth aspect, there is provided an apparatus. The apparatus comprises means for in response to detecting a signal at a device, identifying at least one unit sequence from the signal, wherein a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies a further device transmitting the signal; and means for determining, based on the at least one unit sequence, the further device from the plurality of devices.

In a seventh aspect, there is provided a computer program product that is stored on a computer readable medium and includes machine-executable instructions. The machine-executable instructions, when being executed, cause a machine to perform the method according to the above first or second aspect.

In an eighth aspect, there is a computer readable storage medium comprising program instructions stored thereon. The instructions, when executed by an apparatus, cause the apparatus to perform the method according to the above first or second aspect.

Through the more detailed description of some example embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:.

Further, when a particular feature, structure, or characteristic is described in connection with an example embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

As used herein, the term "communication network" refers to a network following any suitable communication standards, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), Time Division-Long Term Evolution (TD-LTE), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT), New Radio (NR) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (<NUM>), the second generation (<NUM>), <NUM>, <NUM>, the third generation (<NUM>), the fourth generation (<NUM>), <NUM>, the future fifth generation (<NUM>) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term "network device" refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology.

Although functionalities described herein can be performed, in various example embodiments, in a fixed and/or a wireless network node may, in other example embodiments, functionalities may be implemented in a user equipment apparatus (such as a cell phone or tablet computer or laptop computer or desktop computer or mobile IOT device or fixed IOT device). This user equipment apparatus can, for example, be furnished with corresponding capabilities as described in connection with the fixed and/or the wireless network node(s), as appropriate. The user equipment apparatus may be the user equipment and/or or a control device, such as a chipset or processor, configured to control the user equipment when installed therein. Examples of such functionalities include the bootstrapping server function and/or the home subscriber server, which may be implemented in the user equipment apparatus by providing the user equipment apparatus with software configured to cause the user equipment apparatus to perform from the point of view of these functions/nodes.

Atmospheric ducting is a mode of propagation of electromagnetic radiation, usually in lower layers of the Earth's atmosphere, where the waves are bent by atmospheric refraction. In case of atmospheric ducting, a downlink signal of a network device may degrade too little to be ignored by a remote network device. In this case, remote interference between network devices occurs.

Some legacy solution proposes that each network device belonging to a same operator transmits a specific sequence which uniquely identifies the network device. As such, if a network device detects an interference signal from another network device, the network device may identify the specific sequence from the interference signal and then identify the other network device interfering with the network device based on the determined sequence. However, the legacy solution requires that all of the network devices use a same bandwidth and same frequency carriers. Otherwise, the network devices cannot identify each other and thus the interference source cannot be identified.

In some case, the operator spectrum deployment may be complex. Even for a same operator, the bandwidth and frequency carriers used by network devices in different areas may be not the same. In this event, the legacy solution will not be applicable.

Embodiments of the present disclosure provide a solution for signal source identification and determination, so as to solve the above problem and one or more of other potential problems. According to the claimed invention, a device transmits at least one unit sequence, where a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies the device in the plurality of devices. On the other hand, if a device detects a signal, the device identifies at least one unit sequence from the signal, where a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies a further device transmitting the signal. The device determines, based on the at least one unit sequence, the further device from the plurality of devices.

As such, a device suffering interference due to atmospheric ducting can find out an interference source and perform an action to avoid the interference, without requiring all of the devices to use a same bandwidth and same frequency carriers.

<FIG> shows an example communication network <NUM> in which implementations of the present disclosure can be implemented. The communication network <NUM> includes devices <NUM>, <NUM>, <NUM> and <NUM>. In this example, the devices <NUM> and <NUM> are illustrated as terminal devices and the devices <NUM> and <NUM> are illustrated as network devices. The device <NUM> may provide one or more serving cells <NUM> to serve terminal devices, for example, the device <NUM>. The device <NUM> may provide one or more serving cells <NUM> to serve terminal devices, for example, the device <NUM>. In some example embodiments, the network devices <NUM> and <NUM> may belong to a same operator. Alternatively, the network devices <NUM> and <NUM> may belong to different operators.

It is to be understood that the numbers of network devices, terminal devices and serving cells are shown only for the purpose of illustration without suggesting any limitations. The network <NUM> may include any suitable number of network devices, terminal devices and serving cells adapted for implementing embodiments of the present disclosure. In the following, only for the purpose of illustration, the devices <NUM> and <NUM> are also referred to as terminal device <NUM> and <NUM>, respectively. The devices <NUM> and <NUM> are also referred to as network devices <NUM> and <NUM>, respectively.

In the communication network <NUM>, the network device <NUM> can communicate data and control information to the terminal device <NUM> and the terminal device <NUM> can also communication data and control information to the network device <NUM>. The network device <NUM> can communicate data and control information to the terminal device <NUM> and the terminal device <NUM> can also communication data and control information to the network device <NUM>. A link from the network device to the terminal device is referred to as a downlink (DL) or a forward link, while a link from the terminal device to the network device is referred to as an uplink (UL) or a reverse link.

Communications in the communication system <NUM> may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (<NUM>), the second generation (<NUM>), the third generation (<NUM>), the fourth generation (<NUM>) and the fifth generation (<NUM>) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) <NUM> and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Divided Multiple Address (CDMA), Frequency Divided Multiple Address (FDMA), Time Divided Multiple Address (TDMA), Frequency Divided Duplexer (FDD), Time Divided Duplexer (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Divided Multiple Access (OFDMA) and/or any other technologies currently known or to be developed in the future.

In case of atmospheric ducting, for example, a signal transmitted by the device <NUM> may degrade too little to be ignored by the device <NUM>. In this case, remote interference between the devices <NUM> and <NUM> occurs. In order to enable the device <NUM> to identify the interference source (for example, the device <NUM>), the device <NUM> may transmit a specific sequence that uniquely identifies the device <NUM>. In response to detecting a signal from the device <NUM>, the device <NUM> can identify the specific sequence from the signal and then determine the signal source (for example, the network device <NUM>) based on the identified sequence.

<FIG> shows a flowchart of a method <NUM> for identifying a signal source in accordance with the claimed invention. For example, the method <NUM> can be implemented at the device <NUM> as shown in <FIG>. It is to be understood that the method <NUM> may include additional blocks not shown and/or may omit some shown blocks, and the scope of the present disclosure is not limited in this regard.

At block <NUM>, the device <NUM> transmits at least one unit sequence to a further device (for example, the device <NUM> and/or <NUM>), where a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies the device in the plurality of devices.

In some example embodiments, a plurality of unit sequences may be generated and stored at the device <NUM> for identifying the plurality of devices. The device <NUM> may selects, from the plurality of unit sequences, at least one unit sequence that uniquely identifies the device <NUM> in the plurality of devices.

In some example embodiments, the number of unit sequences to be generated may depend on the number of network devices or cells to be identified. For example, if there are <NUM> network devices or cells to be identified, <NUM> unit sequences may be generated. Alternatively, if the device <NUM> can transmit two different signals generated from two different unit sequences in two different sub-frames, <NUM> unit sequences can be used to identify <NUM> network devices or cells.

In some example embodiments, the network device <NUM> may belong to an operator. In some example embodiments, a bandwidth of each unit sequence to be generated may be a common divisor of comprehensive overlapping system bandwidths among a plurality of cells in the operator's network. An overlapping system bandwidth refers to the overlapping part of system bandwidths of any two of the plurality of network devices or cells. The comprehensive overlapping system bandwidths refer to a collection of overlapping system bandwidths among the plurality of network devices or cells in the operator's network. For example, the bandwidth of each unit sequence may equal to the greatest common divisor of the overlapping system bandwidths among the plurality of cells. Moreover, the bandwidth of each unit sequence can be divided by respective system bandwidths of the plurality of cells.

<FIG> show diagrams of an example for determining a bandwidth of a unit sequence based on overlapping bandwidths among network devices in accordance with some example embodiments of the present disclosure.

As shown in <FIG>, for example, an operator may deploy network devices in different areas <NUM>, <NUM> and <NUM>. The network device deployed in the area <NUM> may provide a cell <NUM>. The system bandwidth of the cell <NUM> may be <NUM>. For example, the cell <NUM> is configured with frequency carriers in <NUM>~<NUM>. The network device(s) deployed in the area <NUM> may provide cells <NUM> and <NUM>. The system bandwidth of the cell <NUM> may be <NUM>. For example, the cell <NUM> is configured with frequency carriers in <NUM>~<NUM>. The system bandwidth of the cell <NUM> may be <NUM>. For example, the cell <NUM> is configured with frequency carriers in <NUM>~<NUM>. The network device(s) deployed in the area <NUM> may provide cells <NUM> and <NUM>. The system bandwidth of the cell <NUM> may be <NUM>. For example, the cell <NUM> is configured with frequency carriers in <NUM>~<NUM>. The system bandwidth of the cell <NUM> may be <NUM>. For example, the cell <NUM> is configured with frequency carriers in <NUM>~<NUM>.

According to the above spectrum deployment, there are overlapping system bandwidths among the cells <NUM>, <NUM>, <NUM>, <NUM> and <NUM>, as shown in <FIG>. For example, the overlapping bandwidth between the cells <NUM> and <NUM> is <NUM>. The overlapping bandwidth between the cells <NUM> and <NUM> is <NUM>. The overlapping bandwidth between the cells <NUM> and <NUM> is <NUM>. The overlapping bandwidth between the cells <NUM> and <NUM> is <NUM>. The overlapping bandwidth between the cells <NUM> and <NUM> is <NUM>. The greatest common divisor of the overlapping system bandwidths among the cells is <NUM>. Moreover, <NUM> can be divided by respective system bandwidths of the cells. As such, <NUM> can be determined as the bandwidth of the unit sequence.

<FIG> shows a diagram of a unit sequence <NUM> in accordance with some example embodiments of the present disclosure. As shown in <FIG>, the bandwidth of the unit sequence <NUM> is split into two guard band parts <NUM> and <NUM> at both sides and one sequence part <NUM> in the middle.

In some example embodiments, the bandwidth of the guard band can be determined based on the maximum guard band from all of system bandwidth options in the operator's network. For example, in TD-LTE cells, there are <NUM> system bandwidth options <NUM>, <NUM> and <NUM>, among which <NUM> guard band per side from the <NUM> system bandwidth option is the maximum one. As such, <NUM> guard band per side can be applied to the unit sequence <NUM>. That is, if the bandwidth of the unit sequence <NUM> is determined as <NUM>, the bandwidth of each of the guard band parts <NUM> and <NUM> may be <NUM> and the bandwidth of the sequence part <NUM> may be <NUM>.

In some example embodiments, the length of the sequence part <NUM> and the length of the guard band parts <NUM> and <NUM> may be in units of subcarriers. In some example embodiments, the number of subcarriers configured for the guard band may follow principles as below: (<NUM>) the accumulated bandwidth of subcarriers configured for a guard band should be not lower than the above determined bandwidth of the guard band; and (<NUM>) after configuring subcarriers for the guard band, the bandwidth of subcarriers configured for the sequence part should not exceed the above determined bandwidth of the sequence part. For example, if <NUM> is used as the bandwidth of the guard band per side and if a subcarrier interval in the system is <NUM>, the length of the guard band part <NUM> or <NUM> may be not lower than <NUM>. If each of the guard band parts <NUM> and <NUM> has a length of <NUM>, the bandwidth of the sequence part <NUM> may be at most <NUM> (that is, <NUM> - <NUM>*<NUM>*<NUM>). Thus, the sequence part <NUM> may have a length of <NUM> (that is, <NUM> / <NUM>).

In some example embodiments, if the bandwidth of a unit sequence locates at the edge of the system bandwidth, the guard band of the unit sequence may exclude the system guard band part at the edge of system bandwidth. For example, if the bandwidth of a unit sequence locates at the highest edge of the <NUM> system bandwidth, since there is a <NUM> guard band at that side, the guard band of the unit sequence may only occupy a bandwidth of <NUM> (that is, <NUM> -<NUM>) and at least <NUM> subcarriers.

In some example embodiments, the sequence part <NUM> may be derived from a pre-determined sequence. For example, the pre-determined sequence may be a Gold sequence, a Zadoff-Chu sequence, or any other sequence. In some example embodiments, after applying Binary Phase Shift Keying (BPSK) modulation, Fast Fourier Transform (FFT) and zero padding to the pre-determined sequence, the modulated sequence part can be generated as: <MAT> where ID represents an identifier allocated for each unit sequence. For example, if <NUM> sequences are generated, then ID = <NUM>, <NUM>, <NUM>. Nlength represents the sequence length of the unit sequence. For example, in the above example, Nlength = <NUM>. In some example embodiments, by applying inverse FFT (iFFT), Circle Prefix (CP) Insertion and <NUM>/<NUM> subcarrier offset to the modulated sequence part as shown in the above formula (<NUM>), the sequence part <NUM> can be generated.

As such, the plurality of unit sequences can be generated. In some example embodiments, the device <NUM> may select, from the plurality of unit sequences, the at least one unit sequence uniquely identifying the device in the operator's network.

In some example embodiments, the device <NUM> may determine, based on an identifier of the device, at least one sequence identifier of the at least one unit sequence. The device <NUM> may select, based on the at least one sequence identifier, the at least one unit sequence from the plurality of unit sequences.

In some example embodiments, if the device <NUM> can transmit two different signals generated from two different unit sequences in two different sub-frames, the device <NUM> may determine, based on an identifier of the device, a first sequence identifier and a second sequence identifier which uniquely identify the device <NUM>. The device <NUM> may select, based on the first and second sequence identifiers, a first unit sequence and a second unit sequence from the plurality of unit sequences.

In some example embodiments, in order to transmit the at least one sequence, the device <NUM> may generate, based on the bandwidth of each unit sequence and a system bandwidth of the device <NUM>, at least one signal by assembling the at least one unit sequence. Then, the device <NUM> may transmit the at least one signal to the further device (for example, the device <NUM> and/or <NUM>).

In some example embodiments, the at least one unit sequence may comprise only one unit sequence. The device <NUM> may generate a signal by assembling a number of the unit sequences, where the number is determined by dividing the system bandwidth of the device <NUM> by the bandwidth of each unit sequence. The device <NUM> may then transmit the generated signal to the further device (for example, the device <NUM> and/or <NUM>).

<FIG> shows diagrams of examples for generate a signal by assembling a unit sequence in accordance with some example embodiments of the present disclosure. As shown in <FIG>, if the bandwidth of one unit sequence is <NUM> and the system bandwidth is <NUM>, then the signal can be generated by assembling only one unit sequence. If the bandwidth of one unit sequence is <NUM> and the system bandwidth is <NUM>, then the signal can be generated by assembling two unit sequences. If the bandwidth of one unit sequence is <NUM> and the system bandwidth is <NUM>, then the signal can be generated by assembling three unit sequences. If the bandwidth of one unit sequence is <NUM> and the system bandwidth is <NUM>, then the signal can be generated by assembling four unit sequences.

In some example embodiments, if the device <NUM> can transmit two different signals generated from two different unit sequences in two different sub-frames, the device <NUM> may select the first unit sequence and the second unit sequence from the plurality of unit sequences. The device <NUM> may generate, by assembling a number of the first unit sequences, a first signal to be transmitted in a first sub-frame, where the number is determined by dividing the system bandwidth of the device by the bandwidth of each unit sequence. The device <NUM> may generate, by assembling the number of the second unit sequences, a second signal to be transmitted in a second sub-frame. Then, the device <NUM> may transmit the first signal to the further device in the first sub-frame and transmit the second signal to the further device in the second sub-frame.

In some example embodiments, in a TDD LTE network, the at least one signal comprising the at least one unit sequence may be transmitted in any of the following: a Downlink Pilot Time Slot (DwPTS), an Uplink Pilot Time Slot (UpPTS), a Guard Period (GP), or a traffic time slot of a sub-frame. In some example embodiments, in a FDD LTE network, if there is overlap between downlink and uplink bandwidths of different operators in some scenario, the at least one signal comprising the at least one unit sequence may be transmitted in any suitable position in the frame pattern of the device <NUM>.

In some example embodiments, the device <NUM> may determine a proper timing position in its frame pattern to transmit the at least one signal comprising the at least one unit sequence. The timing position can facilitate another device (for example, the device <NUM>) to determine its distance from the device <NUM>. In some example embodiments, the other device (for example, the device <NUM>) can determine its distance from the device <NUM> as following: <MAT> where P1 represents the timing position at which the at least one signal is detected, P0 represents the timing position at which the at least one signal is transmitted, and V represents the speed of the signal in atmospheric ducting. For example, the device <NUM> may transmit the at least one signal comprising the at least one unit sequence at the head of its Guard Period (GP), i.e., in the No.<NUM> symbol of its specific sub-frame. The other device (for example, the device <NUM>) can detect the at least one signal comprising the at least one unit sequence in the same sub-frame. For example, if each symbol lasts nearly <NUM>, and the signal speed in atmospheric ducting is nearly <NUM>/us, the other device (for example, the device <NUM>) can determine its distance from the device <NUM> as below: (<NUM>-<NUM>) * <NUM> * <NUM>/us = <NUM>.

In some example embodiments, the plurality of unit sequences may be stored by each of network devices in an operator's network. As such, if a network device detects an interference signal, the network device may determine the unit sequence comprised in the interference signal from the plurality of unit sequences and identify the signal source based on the determined unit sequence. Alternatively, or in addition, in some example embodiments, different operators may correspond to different sets of unit sequences. A network device can store different sets of unit sequences corresponding to different operators, and thus can identify an interference source belong to other operators.

<FIG> shows a flowchart of an example method <NUM> for signal source determination in accordance with some example embodiments of the present disclosure. The method <NUM> can be implemented at the device <NUM> as shown in <FIG>. It is to be understood that the method <NUM> may include additional blocks not shown and/or may omit some shown blocks, and the scope of the present disclosure is not limited in this regard.

At block <NUM>, the device <NUM> determines if a signal (for example, an interference signal) is detected. In response to the signal being detected, at block <NUM>, the device <NUM> identifies at least one unit sequence from the signal. A bandwidth of each unit sequence may be a common divisor of comprehensive overlapping system bandwidths among a plurality of devices in an operator's network.

In some example embodiments, the device <NUM> may be included in the plurality of devices. Alternatively, the device <NUM> and the plurality of devices may belong to different operators.

In some example embodiments, in a TDD LTE network, the signal may be detected in any of the following: a Downlink Pilot Time Slot (DwPTS), an Uplink Pilot Time Slot (UpPTS), a Guard Period (GP), or a traffic time slot of a sub-frame. In some example embodiments, in a FDD LTE network, if there is overlap between downlink and uplink bandwidths of different operators in some scenario, the signal may be detected in any suitable position in the frame pattern of the device <NUM>.

In some example embodiments, for example, prior to detecting the signal, a plurality of unit sequences for identifying the plurality of devices may be generated and stored at the device <NUM>. The device <NUM> may determine, from the plurality of unit sequences, the at least one unit sequence comprised in the signal.

In some example embodiments, in order to determine the at least one unit sequence comprised in the signal, the device <NUM> may divide, based on the bandwidth of each unit sequence, a system bandwidth of the device into at least one segment. The bandwidth of each segment equals to the bandwidth of each unit sequence. The device <NUM> may determine correlations between the signal and the plurality of unit sequences in each of the at least one segment. In response to a correlation between the signal and a unit sequence of the plurality of unit sequences exceeding a threshold, the device <NUM> may determine the unit sequence as one of the at least one unit sequence. As such, the device <NUM> can determine the at least one unit sequence comprised in the signal.

At block <NUM>, the device <NUM> determines, based on the at least one unit sequence and from the plurality of devices, a further device transmitting the signal. In some example embodiments, the at least one unit sequence may uniquely identify a further device (for example, the device <NUM>) transmitting the signal, which interferes with the device <NUM>. Therefore, the device <NUM> can determines, based on the at least one unit sequence, the further device from the plurality of devices.

In view of the above, it can be seen that embodiments of the present disclosure provide a solution for signal source identification and determination. According to embodiments of the present disclosure, a device may transmit at least one unit sequence, where a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies the device in the plurality of devices. On the other hand, if a device detects a signal, the device may identify at least one unit sequence from the signal, where a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies a further device transmitting the signal. The device may determine, based on the at least one unit sequence, the further device from the plurality of devices.

In some example embodiments, an apparatus capable of performing the method <NUM> may comprise means for performing the respective steps of the method <NUM>. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus capable of performing the method <NUM> (for example, the device <NUM>) comprises means for transmitting, from a device, at least one unit sequence to a further device, wherein a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies the device in the plurality of devices.

In some example embodiments, the means for transmitting the at least one unit sequence comprises: means for generating, based on the bandwidth of each unit sequence and a system bandwidth of the device, at least one signal by assembling the at least one unit sequence; and means for transmitting the at least one signal to the further device.

In some example embodiments, the at least one unit sequence comprises a first unit sequence. The means for generating the at least one signal comprises: means for generating a signal by assembling a number of the first unit sequences, the number determined by dividing the system bandwidth of the device by the bandwidth of each unit sequence.

In some example embodiments, the at least one unit sequence comprises a first unit sequence and a second unit sequence. The means for generating the at least one signal comprises: means for generating, by assembling a number of the first unit sequences, a first signal to be transmitted in a first sub-frame, the number determined by dividing the system bandwidth of the device by the bandwidth of each unit sequence; and means for generating, by assembling the number of the second unit sequences, a second signal to be transmitted in a second sub-frame.

In some example embodiments, the means for transmitting the at least one signal to the further device comprises: means for transmitting the first signal to the further device in the first sub-frame; and means for transmitting the second signal to the further device in the second sub-frame.

In some example embodiments, the apparatus capable of performing the method <NUM> further comprises: means for generating a plurality of unit sequences for identifying the plurality of devices; means for determining, based on an identifier of the device, at least one sequence identifier of the at least one unit sequence; and means for selecting, based on the at least one sequence identifier, the at least one unit sequence from a plurality of unit sequences.

In some example embodiments, the means for generating the plurality of unit sequences comprises: means for allocating a sequence identifier for a unit sequence of the plurality of unit sequences; means for determining the bandwidth of the unit sequence based on the common divisor of the comprehensive overlapping system bandwidths among the plurality of devices; means for determining, based on the bandwidth and a sub-carrier interval, a sequence length of the unit sequence; and means for generating, based on a pre-determined sequence and the sequence identifier, the unit sequence having the bandwidth and the sequence length.

In some example embodiments, the pre-determined sequence comprises any of the following: a gold sequence and a Zadoff-Chu sequence.

In some example embodiments, each of the plurality of unit sequences comprises two guard band parts and a sequence part between the two guard band parts.

In some example embodiments, the device is a network device and the plurality of devices comprising the device are a plurality of network devices belonging to a same operator.

In some example embodiments, the at least one sequence is transmitted in a TDD communication system in any of the following: a Downlink Pilot Time Slot; an Uplink Pilot Time Slot; a Guard Period; and a traffic time slot.

In some example embodiments, the apparatus capable of performing the method <NUM> (for example, the device <NUM>) comprises: means for in response to detecting a signal at a device, identifying at least one unit sequence from the signal, wherein a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies a further device transmitting the signal; and means for determining, based on the at least one unit sequence, the further device from the plurality of devices.

In some example embodiments, the means for identifying the at least one unit sequence comprises: means for dividing, based on the bandwidth of each unit sequence, a system bandwidth of the device into at least one segment; means for determining, in each of the at least one segment, correlations between the signal and a plurality of unit sequences stored at the device; and means for in response to a correlation between the signal and a unit sequence of the plurality of unit sequences exceeding a threshold, determining the unit sequence as one of the at least one unit sequence.

In some example embodiments, the device is a network device, the further device is a further network device and the plurality of devices are a plurality of network devices comprising the further network device.

In some example embodiments, the plurality of devices comprise the device and belong to a same operator.

In some example embodiments, the plurality of devices belong to a first operator and the device belongs to a second operator different from the first operator.

In some example embodiments, the signal is detected in a TDD communication system in any of the following: a Downlink Pilot Time Slot; an Uplink Pilot Time Slot; a Guard Period; and a traffic time slot.

<FIG> is a simplified block diagram of a device <NUM> that is suitable for implementing embodiments of the present disclosure. For example, the devices <NUM>, <NUM> and/or <NUM> as shown in <FIG> can be implemented by the device <NUM>. As shown, the device <NUM> includes one or more processors <NUM>, one or more memories <NUM> coupled to the processor <NUM>, and one or more communication modules <NUM> coupled to the processor <NUM>.

The embodiments of the present disclosure may be implemented by means of the program <NUM> so that the device <NUM> may perform any process of the disclosure as discussed with reference to <FIG> and <FIG>.

It should be appreciated that future networks may utilize network functions virtualization (NFV) which is a network architecture concept that proposes virtualizing network node functions into "building blocks" or entities that may be operationally connected or linked together to provide services. A virtualized network function (VNF) may comprise one or more virtual machines running computer program codes using standard or general type servers instead of customized hardware. Cloud computing or data storage may also be utilized. In radio communications, this may mean node operations to be carried out, at least partly, in a central/centralized unit, CU, (e.g. server, host or node) operationally coupled to distributed unit, DU, (e.g. a radio head/node). It should also be understood that the distribution of labour between core network operations and base station operations may vary depending on implementation.

In an embodiment, the server may generate a virtual network through which the server communicates with the distributed unit. In general, virtual networking may involve a process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Such virtual network may provide flexible distribution of operations between the server and the radio head/node. In practice, any digital signal processing task may be performed in either the CU or the DU and the boundary where the responsibility is shifted between the CU and the DU may be selected according to implementation.

Therefore, in an embodiment, a CU-DU architecture is implemented. In such case the apparatus <NUM> may be comprised in a central unit (e.g. a control unit, an edge cloud server, a server) operatively coupled (e.g. via a wireless or wired network) to a distributed unit (e.g. a remote radio head/node). That is, the central unit (e.g. an edge cloud server) and the distributed unit may be stand-alone apparatuses communicating with each other via a radio path or via a wired connection. Alternatively, they may be in a same entity communicating via a wired connection, etc. The edge cloud or edge cloud server may serve a plurality of distributed units or a radio access networks. In an embodiment, at least some of the described processes may be performed by the central unit. In another embodiment, the apparatus <NUM> may be instead comprised in the distributed unit, and at least some of the described processes may be performed by the distributed unit.

In an embodiment, the execution of at least some of the functionalities of the apparatus <NUM> may be shared between two physically separate devices (DU and CU) forming one operational entity. Therefore, the apparatus may be seen to depict the operational entity comprising one or more physically separate devices for executing at least some of the described processes. In an embodiment, such CU-DU architecture may provide flexible distribution of operations between the CU and the DU. In practice, any digital signal processing task may be performed in either the CU or the DU and the boundary where the responsibility is shifted between the CU and the DU may be selected according to implementation. In an embodiment, the apparatus <NUM> controls the execution of the processes, regardless of the location of the apparatus and regardless of where the processes/functions are carried out.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method <NUM> as described above with reference to <FIG> and/or the method <NUM> as described above with reference to <FIG>. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Claim 1:
A method for identifying a signal source, comprising: transmitting (<NUM>), from a device (<NUM>), at least one unit sequence to a further device (<NUM>, <NUM>), wherein a bandwidth of each unit sequence is a common divisor of comprehensive overlapping system bandwidths among a plurality of devices and the at least one unit sequence uniquely identifies the device in the plurality of devices.