CN110401460B

CN110401460B - Method, apparatus, and computer storage medium for voltage standing wave ratio detection of a device

Info

Publication number: CN110401460B
Application number: CN201810375237.6A
Authority: CN
Inventors: 杨维; 陈洪勋
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2018-04-24
Filing date: 2018-04-24
Publication date: 2022-03-04
Anticipated expiration: 2038-04-24
Also published as: CN110401460A

Abstract

Embodiments of the present disclosure provide methods, apparatuses, and computer readable media for Voltage Standing Wave Ratio (VSWR) detection for devices in a communication system. A method includes determining a time period for transmit beamforming calibration of a device during which the device transmits signals over a plurality of transmit channels; and detecting the VSWR of the plurality of transmit channels of the device during the determined time period. With the embodiments of the present disclosure, the accuracy of VSWR detection can be improved.

Description

Method, apparatus, and computer storage medium for voltage standing wave ratio detection of a device

Technical Field

Embodiments of the present disclosure relate generally to the field of communication systems, and, in particular, to a method, apparatus, and computer storage medium for voltage standing wave ratio detection in a communication system.

Background

The statements in this section are intended to facilitate a better understanding of the present disclosure. Accordingly, the contents of this section should be read on this basis and should not be construed as an admission as to which pertains to the prior art or which does not.

The Voltage Standing Wave Ratio (VSWR) is a parameter commonly used in radio frequency technology to measure whether the matching between components is good and the device is working properly. A VSWR detection value of the device above a certain threshold value means that the transmission efficiency is too low and a VSWR alarm will be triggered. In this case, the device may be considered to be malfunctioning and may be returned to the device manufacturer by the user (e.g., a network operator). However, a false VSWR alarm may be triggered if the accuracy of VSWR detection is low and cause the operator to erroneously return the device to the device manufacturer.

Disclosure of Invention

The present disclosure presents methods, apparatuses, and computer storage media for VSWR detection for devices in a communication network.

In a first aspect of the present disclosure, a method for detecting a VSWR of a device is provided. The method comprises the following steps: determining a time period for transmit beamforming calibration of the device during which the device transmits signals over a plurality of transmit channels; and detecting VSWRs of a plurality of transmit channels of the device during the determined time period.

In some embodiments, detecting the VSWR of the plurality of transmit channels of the device during the time period may include: determining a start time for transmitting a beamforming calibration in the time period; and starting the detection of the VSWR from the start time.

In another embodiment, the detection of the VSWR from the start time may include: the path for said detection of VSWR is switched on at the starting time by the switching means.

In yet another embodiment, detecting the VSWR of the plurality of transmit channels of the device during the time period may include: determining a number of samples used for transmit beamforming calibration in the time period; and performing VSWR detection using signal samples less than or equal to the number of samples.

In some embodiments, the VSWR of each of the plurality of transmission channels may be detected in a time-division manner during the period.

In some embodiments, detecting VSWRs for multiple transmit channels of a device may include: measuring a signal power transmitted through a transmission channel of the plurality of transmission channels and a reflected signal power; and detecting a VSWR of a transmission channel of the plurality of transmission channels based on the measurement.

In some embodiments, the time period for transmit beamforming calibration of the device is located in a Guard Period (GP) in a special subframe of a Time Division Duplex (TDD) system or in a designated symbol time period of a Frequency Division Duplex (FDD) system.

In still other embodiments, the apparatus may comprise a Remote Radio Unit (RRU) operating in a TDD or FDD system.

In a second aspect of the disclosure, a communication device is provided. The communication device comprises at least one processor, and at least one memory having computer program code stored thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the communication device at least to perform the method described in the first aspect of the disclosure.

In a third aspect of the present disclosure, a method for detecting a VSWR of a device is provided. The method comprises the following steps: determining a time period for VSWR detection in a GP in a special subframe of a TDD system; transmitting signals through a plurality of transmission channels in the time period; and detecting VSWRs of the plurality of transmission channels based on the transmitted signals during the period.

In a fourth aspect of the present disclosure, there is provided a computer program product comprising instructions which, when executed on one or more processors, cause performance of any of the methods according to the first or third aspects of the present disclosure.

In a fifth aspect of the present disclosure, a computer-readable storage medium having a computer program stored thereon is provided. The computer program, when executed on at least one processor, causes any of the methods according to the first or third aspects of the disclosure to be performed.

Drawings

Some example embodiments of the present disclosure will be described below with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or equivalent elements. The accompanying drawings are only for the purpose of promoting a better understanding of embodiments of the disclosure, and are not necessarily drawn to scale, wherein:

fig. 1 illustrates a schematic diagram of an example wireless communication system in which embodiments of the present disclosure can be implemented;

fig. 2 shows a schematic block diagram of an RRU according to an embodiment of the present disclosure;

fig. 3 illustrates a flow of a method for VSWR detection in accordance with an embodiment of the present disclosure;

fig. 4 shows a schematic diagram of a frame structure of a TDD system;

fig. 5 shows a schematic diagram of a time period for transmit beamforming calibration according to an embodiment of the present disclosure;

fig. 6 illustrates example operations for VSWR detection according to embodiments of the present disclosure;

fig. 7 illustrates a timing sequence for controlling VSWR detection according to an embodiment of the disclosure;

fig. 8 illustrates example operations for VSWR detection according to embodiments of the present disclosure;

fig. 9 illustrates a schematic signal diagram for VSWR detection according to an embodiment of the present disclosure;

fig. 10 illustrates a flow of another method for VSWR detection in accordance with an embodiment of the present disclosure;

fig. 11 illustrates a flow diagram of a method for VSWR detection for a TDD device in accordance with an embodiment of the present disclosure; and

fig. 12 shows a simplified block diagram of a network device according to an embodiment of the present disclosure.

Detailed Description

It is understood that all of these examples in this disclosure are given solely for the purpose of enabling those skilled in the art to better understand and further practice the disclosure, and are not intended to limit the scope of the disclosure. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. For clarity, some features of the actual implementation described in this specification may be omitted.

References in the specification to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," comprising, "" has, "" having, "" includes, "" including, "" has, "" having, "" contains, "" containing, "" contains, "" contain a mixture of one or more other features, elements, components, and/or combinations thereof. The term "optional" means that the embodiment or implementation being described is not mandatory, and may be omitted in some cases.

As used in this disclosure, the term "circuitry" may refer to one or more or all of the following: (a) hardware circuit implementations only (e.g., analog and/or digital circuit implementations only), (b) a combination of hardware circuits and software, and (c) hardware circuits and/or processors (such as microprocessors or portions of microprocessors) that require software (e.g., firmware) for operation, but that may not be present when software is not required for the operation. Combinations of hardware circuitry and software may include, among others, such as (as applicable): (i) a combination of analog and/or digital hardware circuitry with software/firmware, and (ii) any portion of a hardware processor with software (including a digital signal processor), software, and memory that work together to cause a device such as a mobile phone or server to perform various functions. This definition of circuitry applies to all uses of this term in this application, including any claims. As a further example, as used in this application, the term circuitry also encompasses only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also encompasses, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

Further, as used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-advanced (LTE-a), Wideband Code Division Multiple Access (WCDMA), High Speed Packet Access (HSPA), CDMA2000, time division synchronous code division multiple access (TD-CDMA), and the like. Further, communication between devices in the communication network may be performed according to any suitable communication protocol, including but not limited to global system for mobile communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), and/or other suitable communication protocols, such as first generation (1G), second generation (2G), 2.5G, 2.75G, 3G, 4G, 4.5G, 5G communication protocols, Wireless Local Area Network (WLAN) standards (such as IEEE 802.11 standards); and/or any other suitable wireless communication standard, and/or any other protocol now known or later developed in the future.

As used herein, the term "network device" refers to a device in a communication network via which a terminal device may access the network and receive services therefrom. Depending on the terminology and technology used, a network device may refer to a Base Station (BS), an Access Point (AP), a Remote Radio Unit (RRU), and so on.

The term "terminal device" refers to any device having communication capabilities. By way of example, and not limitation, a terminal device may be referred to as a User Equipment (UE), Subscriber Station (SS), portable subscriber station, Mobile Station (MS), or Access Terminal (AT). The terminal devices may also include, but are not limited to, mobile phones, cellular phones, smart phones, voice over IP (VoIP) phones, tablet computers, wearable terminal devices, Personal Digital Assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop installation devices (LMEs), USB dongles, smart devices, wireless Customer Premises Equipment (CPE), D2D devices, machine-to-machine (M2M) devices, MTC devices, V2X devices, and the like. In the following description, the terms "terminal device", "terminal", "user equipment" and "UE" may be used interchangeably.

A schematic diagram of an example communication network 100 in which embodiments of the present disclosure can be implemented is shown in fig. 1. Communication network 100 may include one or more network devices 101. For example, in this example, network device 101 may be embodied as a base station, e.g., a node b (nb), an evolved node b (enb), or a 5GNB (also referred to as a GNB). It should be understood that the network device 101 may also be embodied as a relay or RRU, etc. Network device 101 provides wireless connectivity to a plurality of terminal devices 111-1, 111-2, and 111-3 (hereinafter collectively referred to as terminal devices 111) within its coverage area. Transmissions from network device 101 to terminal device 111 may be referred to as Downlink (DL) transmissions and transmissions in the opposite direction as Uplink (UL) link transmissions.

In the wireless communication system 100 of fig. 1, one important parameter for characterizing the performance of the network device 101 is the VSWR. The value of this parameter indicates the transmission efficiency of the network device 101.

Currently, whether for Frequency Division Duplex (FDD) or TDD systems, the detected value of the VSWR is typically obtained during transmission of downlink traffic through a feedback path of a transmitter in network device 101. However, the inventors of the present disclosure have recognized that performing VSWR detection during transmission of downlink traffic may adversely affect or limit normal downlink traffic. In addition, due to the application of beam forming in FDD and TDD systems, such a conventional VSWR detection method may cause the VSWR detection accuracy of network devices to be reduced and trigger false VSWR alarms in some communication scenarios.

For example, more and more operators are demanding network equipment (e.g., RRUs) with Beamforming (BF) functionality to be employed in communication systems. However, in some customer application scenarios, depending on the beamforming factor/weight configuration and isolation performance of the antenna array, the VSWR detection accuracy of the network device may degrade and trigger false VSWR alarms and cause the operator to erroneously return the network device to the vendor.

In particular, for a network device (e.g., RRU), if the BF function is enabled and the configured BF factor/weight varies between 0.2 and 1, the output power of different channels in the RRU may differ by up to 14 dB. The following is illustrated by way of example with the TDD RRU200 shown in fig. 2 having 8 channels and 43dBm transmit power per channel (denoted as 8x 20W). In this RRU200, data from a baseband unit (BBU)201 is processed through one or more of channels 1-8 and transmitted via an antenna array 202. If channel 1 in RRU200 is configured with a BF factor/weight of 0.2 and channel 2 is configured with a BF factor of 1, the output power of channel 2 in this case is 20W (43dBm) and the output power of channel 1 is only 794mW (29 dBm). Therefore, the transmit power of lane 1 is 14dB different from the transmit power of lane 2.

In this case, if the primary alarm threshold for VSWR is set to 1.9 (equivalent to 10dB) and the typical antenna isolation is 20dB, then the VSWR alarm for lane 1 may be falsely triggered. This is because the interference power from channel 2 is 23dBm, which is only 6dB lower than the output power of channel 1, resulting in the VSWR of channel 1 being detected as being below the primary alarm threshold.

For future, e.g., 5G RRUs with up to 64 or 128 channels, the interference due to the transmit power imbalance may be more severe and therefore the VSWR detection may be worse.

One possible solution to the above problem is to reduce the interference by increasing the isolation between the channels. However, it is difficult to improve the isolation between channels due to the size of the network device. In addition, the investment of equipment manufacturers and operators must be increased in order to increase isolation. Moreover, this solution is more difficult for network devices with a large number of channels, in particular for network devices of the coming massive multiple input multiple output (mimo) type.

Embodiments of the present disclosure present new solutions for VSWR detection. With embodiments of the present disclosure, VSWR detection accuracy may be improved, and thus false VSWR alarms and false device returns may be reduced or avoided. In addition, this solution does not require additional investment by the operator.

Some embodiments of the present disclosure propose to change VSWR detection from a period of transmitting downlink traffic to a period for transmit BF calibration where all lanes are transmitting the same power level signal to reduce interference from other lanes with large transmit power. Embodiments of the present disclosure may improve VSWR detection accuracy regardless of the operator configured BF factor.

In some embodiments, the VSWR detection method proposed in the present disclosure can effectively ensure the VSWR detection accuracy of the RRU with BF function, and even can relax the channel isolation requirement to achieve VSWR accuracy comparable to the conventional VSWR detection scheme.

The VSWR detection scheme proposed herein is particularly suitable for RRUs supporting multiple channels, such as 5G RRUs supporting 64 or more channels, which require lower cost and smaller size. It should be understood, however, that embodiments of the present disclosure are not limited to use in this particular network device, but may be used in other network devices and communication scenarios where similar issues exist.

Fig. 3 shows a flow diagram of an example method 300 in accordance with an embodiment of the present disclosure. The example method may be implemented, for example, by network device 101 in wireless communication network 100 in fig. 1. However, the present disclosure is not limited thereto. For ease of discussion only, method 300 will be described below with reference to network device 101 and network environment 100 depicted in fig. 1.

As shown in fig. 3, at block 310, network device 101 determines a time period for the network device to send a BF calibration. In this period, the network device 101 transmits signals through a plurality of transmission channels (e.g., at the same transmission power).

In one embodiment, the time period for the network device 101 to send BF calibration may be located in a Guard Period (GP) in a special subframe of the TDD system. A schematic diagram of a frame structure 400 of a TDD Long Term Evolution (LTE) system is shown in fig. 4. As shown in fig. 4, in this system, one radio frame is 10ms long, which includes two half-frames of 5ms in length. A radio frame of 10ms is divided into 10 subframes, subframe 0 to subframe 9. Each subframe includes slot 0 and slot 1. According to different configurations of DL/UL of the TDD frame structure, each subframe may be configured as a downlink subframe for downlink traffic, an uplink subframe for uplink traffic, or a special subframe, respectively. In the example of fig. 4, subframes 1 and 6 are special subframes. The special subframe includes a downlink pilot time slot (DwPTS) for downlink transmission, an uplink pilot time slot (UpPTS) for uplink transmission, and a GP.

Normally, there is no uplink or downlink transmission in the GP. However, in accordance with embodiments of the present disclosure, transmit BF calibration may be performed in the GP. During the time period in the GP for transmitting the BF calibration, the network device 101 transmits signals through multiple transmission channels. In some embodiments, network device 101 transmits signals at the same transmit power over multiple transmit channels. A schematic diagram of transmit BF calibration during GP is shown in fig. 5.

As shown in fig. 5, transmit BF calibration may be performed in

multiple time intervals

510 and 520. In some embodiments, the calibration is performed periodically. In the example of fig. 5,

time intervals

510 and 520, respectively, may be one TDD special subframe or a portion thereof in a radio frame. As shown in fig. 5,

time intervals

510 and 520 include DwPTS 501 and GP 502, and a time period 530 for sending BF calibration is included in GP 502. During this time period 530, the network device 101 transmits the calibration signal over multiple transmit channels (e.g., at the same transmit power).

In some embodiments, this time period 530 for sending the BF calibration is configurable. By way of example and not limitation, the time period 530 may be configured by a frame offset, a half frame indication, or the like. In other embodiments, where the transmit BF calibration is performed in the GP 502, a predetermined time period 540 may be reserved in the GP 502 for calibration switching prior to calibration.

It should be understood that the present disclosure is not limited to performing transmit BF calibration in any particular implementation. That is, the transmit BF calibration may be performed using any known or future developed method.

Reference is now continued to fig. 3. At block 320, network device 101 detects VSWRs of the multiple transmit lanes of network device 101 during the determined time period (e.g., time period 530 in fig. 5) for transmitting the BF calibration.

Since the network device 101 transmits signals from the respective lanes (e.g., 8 lanes in fig. 2) in this period 530, the problem of increased interference caused by configuring different BF factors is avoided. This results in reduced interference from other channels and improved detection accuracy of the VSWR.

An example operation 600 that may be performed in block 320 of fig. 3 is shown in fig. 6. As shown in fig. 6, at block 610, network device 101 may determine a start time (e.g., start point 531 in fig. 5) for sending the BF calibration in a time period for sending the BF calibration (e.g., time period 530 in fig. 5); and at block 620, starting VSWR detection from the start time. For example, the network device may configure the switch for VSWR detection according to the starting point of the transmit BF calibration such that the trigger point for VSWR detection is located at the starting point of the TX beamforming calibration. That is, network device 101 may begin VSWR detection by switching elements turning on the path for VSWR detection at the start time.

Alternatively or additionally, the VSWR of the multiple transmit lanes of network device 101 may be caused to be detected during the time period for transmitting the BF calibration by adjusting the timing for VSWR detection according to the timing for transmitting the BF calibration.

A timing diagram for implementing VSWR detection during transmit beamforming calibration is schematically illustrated in fig. 7. In this figure, a logic high means enabled and a logic low means disabled. As can be seen from fig. 7, during the time period 701, the transmission partial enable signal level is high, i.e., the transmission channel is enabled, and the baseband board of the network device transmits valid signals of all channels. Also, during time period 702, the enable signal level of one receive channel used to send the BF calibration is also high, i.e., the receive channel is enabled, to enable reception of signals during time period 702. Thus, the transmit BF calibration operation can be performed during the overlapping portions of time intervals 701 and 702 (e.g., during time interval 703 in fig. 7).

In this example, assume that network device 101 transmits a signal for BF calibration in time period 713 in time interval 703. A time period 704 for calibration handover may be configured before network device 101 sends a signal for sending BF calibration. In addition, in this example, as shown in fig. 7, during the time period 705, the enable signal level for VSWR detection is also high, meaning that the network device 101 can perform VSWR detection during this time period. In some embodiments of the present disclosure, network device 101 may perform VSWR detection in a time period when the transmit portion enable signal, the VSWR switch, and the receive portion enable signal for transmitting BF calibration are all high. For example, network device 101 may perform VSWR detection during time period 713 for sending BF calibration.

At time 706, the transmission/reception switching signal level of TDD becomes high, and at the same time the reception section enable signal also becomes high, that is, the network device 101 switches to the reception state. This means that after performing VSWR detection, the network device 101 may perform a receive operation during UpPTS.

Embodiments of the present disclosure are not limited to implementing the timing control shown in fig. 7 in any particular manner. By way of example and not limitation, the timing sequence shown in FIG. 7 may be implemented by controlling the switches of the respective paths. It should be understood that the present disclosure is not limited to a particular switching arrangement for each path.

In some embodiments, network device 101 may configure sampling parameters for VSWR detection (e.g., modify register values of a Digital Predistortion (DPD) output and feedback power meter in network device 101) to ensure that there are a sufficient number of samples for VSWR detection. The sample length for VSWR detection may be different from the number of samples used by DPD for power amplifier linearity optimization in network device 101. In some embodiments, the sampling length for VSWR detection may be less than or equal to the sampling length for transmitting the calibration signal (e.g., the sampling length in time period 530 in fig. 5, or the sampling length in time period 713 in fig. 7).

As an example, an example of operations 800 for VSWR detection that may be performed by network device 101 is shown in fig. 8. This operation 800 may be performed in block 320 of fig. 3. As shown in fig. 8, in block 810, network device 101 may determine a number of samples used to send BF calibration in a time period for sending BF calibration, and perform VSWR detection using less than or equal to the number of samples of the signal at block 820.

By way of example and not limitation, in some embodiments, network device 101 may detect the VSWR of each of the plurality of transmit lanes in a time-division manner in a time period (e.g., time period 530 in fig. 5, or a sample length in time period 713 in fig. 7) for transmitting the BF calibration. VSWR detection for each channel may be performed according to existing methods, and embodiments of the present disclosure are not limited to any particular detection algorithm. By way of example only, in some embodiments, at block 320 of fig. 3, network device 101 may measure a signal power transmitted and a reflected signal power over a transmit channel of the plurality of transmit channels and detect a VSWR for the transmit channel of the plurality of transmit channels based on the measurement.

For purposes of illustration and not limitation, an example signal diagram for VSWR detection for one lane in a network device is schematically illustrated in fig. 9. It should be understood that the components and signals shown in the figures are examples only, and in other embodiments, VSWR detection may involve fewer or more or different components and signals.

In the example of fig. 9, a transmit signal 901 is transmitted from an antenna 970 via a transmit path consisting of a Digital Predistortion (DPD)910, a digital-to-analog converter (DAC)920, a Power Amplifier (PA)930, a coupler 940, a circulator 950, and a filter 960. Meanwhile, the signal reflected from the antenna enters the VSWR detection path through the filter 960 and the circulator 950. The return signal 902 entering the VSWR detection path passes through a digital predistortion receive analog-to-digital converter (PDRX ADC)990 and a digital predistortion receiver (PDRX)991 under control of

switches

980 and 981. The signal power 905 (denoted as Ppdrx herein for simplicity), is sampled at the output of PDRX 991, the signal power 903 (denoted as Ppdpin herein for simplicity) is sampled at the input of the transmit DPD, and the signal power 904 (denoted as Ppdout herein for simplicity) is sampled at the output of the DPD. The VSWR for the channel may be determined based on a measurement of the power of

signals

903, 904, and 905.

For example, the forward signal power P1 and the reverse signal power P2 can be obtained by the following expressions (1) and (2), respectively:

P1＝Pdpdout*F(x) (1)

P2＝Ppdrx*F(y) (2)

wherein f (x), f (y) represent VSWR calibration parameters that are set at the time of factory shipment of the device. The VSWR of the device may be obtained based on the ratio of P1 and P2 (i.e., P1/P2). For example, VSWR and P1/P2 may have the following relationship:

P1/P2＝20log((VSWR+1)/(VSWR-1)) (3)。

the VSWR detection shown in fig. 9 is performed in a time period for transmitting BF calibration. And in this example, synchronization of VSWR detection with BF calibration may be achieved by controlling

switches

980 and 981 to turn on the VSWR detection path at the appropriate time. Where switch 980 turns on the VSWR detection path during the time period for VSWR detection so that VSWR reverse signal 983 enters analog-to-digital converter 990 as an input. The switch 980 may switch off or on the power amplifier linear optimization path to perform a power amplifier linear optimization function during a period of time not used for VSWR detection. In this case, the DPD feedback signal 984 may enter the ADC 990.

It should be noted that in the case of network device 101 having multiple lanes, VSWR detection for each lane may be performed in a similar signal flow. Additionally, in some embodiments, a separate VSWR detection path for each lane is not required. In contrast, one VSWR detection path may be shared by a plurality of channels in a time division manner to reduce required components and reduce costs. For example, in fig. 9, the channel select switch 981 may be controlled to turn on one of the return signals 902, 912, … 972, etc. from different channels at different times to measure the VSWR of the different channels in time division. For example, the return signals 902-907 may be used to measure the VSWR of channels 1-8, respectively, in FIG. 2. Similarly, channel select switch 982 may be used to select the feedback signals of different channels for linearity optimization.

Conventional VSWR detection is performed during the transmission of downlink traffic, and therefore the associated switch needs to switch between the DPD feedback path and the VSWR path in a short time to ensure that all runtime tasks can run in sequence. In contrast, embodiments of the present disclosure allow VSWR detection to be performed during the GP of TDD in the time period in which BF calibration is sent. In the proposed detection scheme, before entering the VSWR detection task, the real-time task information in the previous downlink timeslot may be recorded and all configurations restored after a later detection, ensuring that all other real-time tasks are not affected.

It should be understood that embodiments of the present disclosure are not limited to network devices being applied to TDD systems. In addition, some embodiments of the present disclosure are not limited to performing transmission BF calibration and VSWR detection in GP of a special subframe of a TDD system, but only need to have VSWR detection performed in a period for transmitting BF calibration even if the period is not BF calibrated but only signals for VSWR detection are transmitted.

Furthermore, although the VSWR detection method proposed by the embodiments of the present disclosure may be performed by the RRU, the embodiments of the present disclosure are not limited thereto, but may be applied to other devices having similar problems.

Operations of another example method 1000 for VSWR detection in accordance with embodiments of the present disclosure are described below with reference to fig. 10. The method may be performed, for example, by network device 101 of fig. 1. For simplicity of description, the processing of method 1000 is still described below in connection with network device 101.

As shown in fig. 10, at block 1010, network device 101 configures sampling parameters for VSWR detection (e.g., modifies register values of power meters used to measure DPD output signal and feedback signal) to ensure a sufficient number of samples for VSWR detection.

At block 1020, network device 101 configures timing for VSWR detection. For example, network device 101 may configure a switch in the path for VSWR detection according to the starting point for sending the BF calibration such that the trigger point for VSWR detection is located at the starting point for sending the BF calibration.

At block 1030, the network device 101 sets the corresponding switches in the path for the VSWR measurement (e.g., switches 980 and 981 in fig. 9) such that the switch state in the channel allows detection of the return power.

At block 1040, the network device 101 configures the range and accuracy of the power meter according to the power level of the VSWR, and reads the corresponding signal (e.g., the signals Ppdrx 905 and pdpdpdpdpout 904 in fig. 9 and the value of the Automatic Gain Control (AGC) gain in PDRX for calculating the VSWR) during the time period for sending the BF calibration.

At block 1050, network device 101 determines whether VSWR for the other channels is to be detected during transmit beamforming calibration. If additional channels are to be detected, then a return is made to block 1030 to calculate the VSWR for the specified channel. If all channels have been detected, the current VSWR detection is ended, and if there are other downlink operational tasks, the other operational tasks in the downlink are continued to be performed at block 1060.

Alternatively, some embodiments of the present disclosure also provide another method 1100 for VSWR detection for TDD devices. Example operations of this method 1100 are shown in fig. 11. Method 1100 may be implemented, for example, by network device 101 of fig. 1. For ease of description, the operation of method 1100 is described below with reference to the communication system and network device 101 of fig. 1.

As shown in fig. 11, at block 1110, the network device 101 determines a time period for VSWR detection in a GP in a special subframe of the TDD system. In some embodiments, the time period may coincide or partially coincide with the time period for the network device 101 to send the BF calibration. In other embodiments, the time period may be a separate time period independent of the time period for sending the BF calibration. That is, in some embodiments, VSWR detection and transmission BF calibration are not required to be performed in the same time period; instead, the network device determines a separate time period for VSWR detection in the GP.

At block 1120, the network device 101 transmits signals over multiple transmit channels during the determined time period. In some embodiments, the transmission is performed at the same transmission power over multiple channels. Here, "the same transmission power" includes equal transmission power and transmission power with little difference.

At block 1130, network device 101 detects VSWRs for the multiple transmit lanes during the time period. For example, in some embodiments, VSWR may be detected using equations (1) - (3).

In some embodiments, the scheme of VSWR detection described previously with reference to

methods

300 and 1000 is equally applicable in method 1100, except that the VSWR detection of method 1100 is implemented in the GP of TDD, while the VSWR detection of

methods

300 and 1000 is implemented in the time period used to send the BF calibration.

One aspect of the disclosure also provides a network device. The network device may be, for example, network device 101 shown in fig. 1. In one embodiment, network device 101 includes means for determining a time period for the network device to transmit BF calibration, and means for detecting VSWRs for a plurality of transmit lanes of the network device during the determined time period. During a time period for transmission BF calibration of the network device, the network device transmits signals at the same transmission power through a plurality of transmission channels.

In some embodiments, a network device according to embodiments of the present disclosure includes means for sending BF calibration, means for VSWR detection, and means for controlling. Wherein the means for controlling controls the means for VSWR detection to perform the VSWR detection in a time period for sending the BF calibration. Each of the means for sending BF calibration, the means for VSWR detection, and the means for controlling may be implemented by hardware (e.g., a processor or circuitry), software, firmware, or a combination thereof.

Fig. 12 shows a simplified block diagram of a device 1100 for use in a communication network according to another embodiment of the present disclosure. The device 1200 may be implemented/realized, for example, as the network device 101 shown in fig. 1. The network device 101 includes, but is not limited to, an RRU for TDD or FDD systems.

The device 1200 may include one or more processors 1210 (such as data processors) and one or more memories 1220 coupled to the processors 1210. Device 1200 may also include one or more transmitter/receivers 1240 coupled to processor 1210. The memory 1220 may be a non-transitory machine-readable storage medium and it may store a program or computer program product 1230. The computer program (product) 1230 may include instructions that, when executed on the associated processor 1210, enable the apparatus 1200 to operate according to embodiments of the disclosure (e.g., perform the

methods

300, 600, 800, 1000, and/or 1100). The combination of one or more processors 1210 and one or more memories 1220 may form a processing component 1250 suitable for implementing various embodiments of the present disclosure.

Various embodiments of the disclosure may be implemented by a computer program or computer program product executable by processor 1210, software, firmware, hardware, or combinations thereof.

The memory 1220 may be of any type suitable to the local technical environment, and may be implemented using any suitable data storage technology, such as semiconductor-based memory terminal devices, magnetic memory terminal devices and systems, optical memory terminal devices and systems, fixed memory and removable memory, as non-limiting examples.

The processor 1210 may be of any type suitable to the local technical environment, and may include processing circuitry, general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs), processors based on a multi-core processor architecture, and the like, as non-limiting examples.

Example embodiments herein are described above with reference to block diagrams and flowchart illustrations of methods and apparatus. It should be understood that each block of the block diagrams and flowchart illustrations, and combinations of blocks in the block diagrams and flowchart illustrations, respectively, can be implemented by various means including hardware, software, firmware, and combinations thereof. Hardware includes, for example, hardware circuitry and/or a processor.

For example, in some example embodiments, individual blocks of the block diagrams and flowchart illustrations, and combinations of blocks in the block diagrams and flowchart illustrations, may be implemented in circuitry. Accordingly, an aspect of the present disclosure provides an apparatus comprising circuitry configured to perform method steps, functions, or operations according to embodiments of the present disclosure. As an example, the apparatus may include circuitry configured to perform the methods described with reference to fig. 3-11.

In other example embodiments, individual blocks of the block diagrams and flowchart illustrations, and combinations of blocks in the block diagrams and flowchart illustrations, may be implemented by computer programs or computer program products comprising computer program instructions. These computer program instructions may be loaded onto a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions which execute on the computer or other programmable data processing apparatus create means for implementing the functions specified in the flowchart block or blocks.

In the context of the present disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various operations described above. Examples of a carrier include a machine-readable transmission medium, a machine-readable storage medium, and the like.

Accordingly, the present disclosure also provides a machine-readable transmission medium, which may include, for example, electrical, optical, radio, acoustic, or other forms of propagated signals, such as carrier waves, infrared signals, and the like.

Another aspect of the disclosure also provides a machine-readable storage medium, such as a memory having a computer program or computer program product stored thereon. The machine-readable storage medium may include a computer-readable storage medium such as, but not limited to, a magnetic disk, magnetic tape, optical disk, phase change memory, or an electronic memory terminal device, such as Random Access Memory (RAM), Read Only Memory (ROM), flash memory device, CD-ROM, DVD, Blu-ray disk, and the like.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the subject matter described herein, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

It should also be understood that although some embodiments of the present disclosure are described with reference to the wireless communication system or TDD RRU of fig. 1, this should not be construed as limiting the spirit and scope of the present disclosure. The principles and concepts of the present disclosure may be more generally applied to any communication device, system, and scenario in which similar issues exist.

It will be appreciated by those skilled in the art that as technology advances, the inventive concept can be implemented in various ways. The above-described embodiments are given for the purpose of illustration and not limitation of the present disclosure, and it is to be understood that modifications and variations may be made without departing from the spirit and scope of the present disclosure as readily understood by those skilled in the art. Such modifications and variations are considered to be within the scope of the disclosure and the appended claims. The scope of the disclosure is defined by the appended claims.

The following are some abbreviations and corresponding full names used in the present disclosure.

TDD time division duplex

FDD frequency division duplexing

VSWR voltage standing wave ratio

TX transmitter

DPD digital predistortion

FB feedback

FB _ SW feedback switch

REV-Rev

AGC-automatic gain control

RRU: remote radio unit

BF: beamforming

ADC: analog to digital conversion

DAC: digital to analog conversion

Claims

1. A method for detecting a voltage standing wave ratio, VSWR, of a device, comprising:

determining and reserving a time period for transmit beamforming calibration of the device in which the device transmits signals over a plurality of transmit channels; and

detecting VSWRs of the plurality of transmit lanes of the device in the determined time period.

2. The method of claim 1, wherein detecting the VSWRs for the plurality of transmit channels of the device during the time period comprises:

determining a start time of the transmit beamforming calibration in the time period; and

starting the detection of VSWR from the start time.

3. The method of claim 2, wherein the detecting of a VSWR from the start time comprises:

turning on a path for the detection of VSWR at the start time by a switching component.

4. The method of claim 1, wherein detecting the VSWRs for the plurality of transmit channels of the device during the time period comprises:

determining a number of samples for the transmit beamforming calibration in the time period; and

the detecting is performed using fewer than or equal to the number of signal samples.

5. The method of claim 1, wherein detecting the VSWRs for the plurality of transmit channels of the device during the time period comprises:

detecting a VSWR of each of the plurality of transmission channels in a time division manner during the period.

6. The method of claim 1, wherein detecting VSWRs for the plurality of transmit lanes of the device comprises:

measuring a signal power transmitted through a transmission channel of the plurality of transmission channels and a reflected signal power; and

detecting a VSWR of the transmit lane of the plurality of transmit lanes based on the measurement.

7. The method according to any of claims 1-6, wherein the time period for transmit beamforming calibration of the device is located at a guard period GP in a special subframe of a time division duplex, TDD, system or at a designated symbol time period of a frequency division duplex, FDD, system.

8. The method according to any of claims 1-6, wherein the apparatus comprises a remote radio unit, RRU, operating in a time division duplex, TDD, or frequency division duplex, FDD, system.

9. The method of any of claims 1-6, wherein the device sending signals over multiple transmit channels in the time period comprises: the device transmits signals with the same transmission power through a plurality of transmission channels in the period.

10. A communication device, comprising:

at least one processor, and

at least one memory having computer program code stored thereon,

the at least one memory and the computer program code configured to, with the at least one processor, cause the communication device at least to:

determining and reserving a time period for transmit beamforming calibration of the communication device in which the communication device transmits signals over a plurality of transmit channels; and

detecting Voltage Standing Wave Ratios (VSWRs) of the plurality of transmission channels of the communication device in the determined period of time.

11. The communication device of claim 10, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the communication device to detect VSWRs of the plurality of transmit channels of the device during the time period by:

starting the detection of VSWR from the start time.

12. The communication device of claim 11, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the communication device to turn on a path for the detection of VSWR through a switching component at the start time.

13. The communication device of claim 10, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the communication device to detect VSWRs of the plurality of transmit channels of the device during the time period by:

14. The communication device of claim 10, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the communication device to detect VSWRs of the plurality of transmit channels of the device during the time period by:

15. The communication device of claim 10, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the communication device to detect VSWRs of the plurality of transmit channels of the device by:

16. The communication device of any of claims 10 to 15, wherein the time period for transmit beamforming calibration of the device is located at a guard period GP in a special subframe of a time division duplex, TDD, system or at a designated symbol time period of a frequency division duplex, FDD, system.

17. The communication device according to any of claims 10-15, wherein the communication device comprises a remote radio unit, RRU, operating in a time division duplex, TDD, or frequency division duplex, FDD, system.

18. A computer-readable storage medium having embodied thereon a computer program which, when executed on at least one processor, causes the method according to any one of claims 1-9 to be performed.