CN107801216B

CN107801216B - Method and apparatus for wireless communication

Info

Publication number: CN107801216B
Application number: CN201610805008.4A
Authority: CN
Inventors: 刘斌越; 龚朝华; 佘锋
Original assignee: Nokia Shanghai Bell Co Ltd
Current assignee: Nokia Shanghai Bell Co Ltd
Priority date: 2016-09-06
Filing date: 2016-09-06
Publication date: 2022-05-31
Anticipated expiration: 2036-09-06
Also published as: CN107801216A

Abstract

Embodiments of the present disclosure relate to methods and apparatus for wireless communication. For example, a method at a network device side, such as a base station, includes receiving information from a terminal device regarding a resolution of an analog-to-digital converter in the terminal device; based on the received information, sending an indication of a downlink transmission scheme for the terminal device to the terminal device; and transmitting data to the terminal equipment according to the transmission scheme. A corresponding method implemented at the terminal device, a network device and a terminal device capable of implementing the above method are also disclosed.

Description

Method and apparatus for wireless communication

Technical Field

Embodiments of the present disclosure relate generally to wireless communication systems and, in particular, relate to methods, apparatuses and computer program products for communicating messages between a network device and a terminal device of a wireless communication system to improve communication.

Background

Increasing network capacity and data rates have been an evolving goal of wireless communication networks. In order to achieve data rates on the order of gigabits per second for next generation mobile cellular communication standards (e.g., 5G), one solution is to utilize the millimeter wave (mmWave) frequency band for communication. Millimeter wave band communications provide higher communication bandwidths than current cellular band communication systems. Thus, millimeter wave communication has great potential for providing higher data rates. However, communication in the millimeter-wave band has its own challenges, particularly in terms of hardware cost and performance loss.

Analog-to-digital converters (ADCs) play an important role in modern digital communication systems. High-resolution ADCs (e.g., ADCs having a resolution of 10 to 20 bits) are widely deployed in mobile terminals. High resolution ADCs provide high quality time discrete signal samples with negligible quantization distortion for baseband signal processing. The sampling rate of the ADC at the receiver should not be less than twice the system bandwidth according to the nyquist-shannon sampling theorem to avoid loss of information in the continuous-time signal. Thus, for millimeter wave communication systems, ADCs are required to provide higher sampling rates than cellular band communication systems, e.g., 500M samples per second or higher. An ADC with high sampling may be referred to as a high-speed ADC. Such high speed, high resolution ADCs are generally costly and power consuming. Therefore, such high-speed, high-resolution ADCs are not affordable and undesirable for use in commercial devices such as mobile terminals.

Disclosure of Invention

The following presents a simplified summary of various embodiments in order to provide a basic understanding of some aspects of various embodiments. This summary is not intended to identify key elements or to delineate the scope of the various embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

A first aspect of the present disclosure provides a method in a network device in a wireless communication system. The method comprises the following steps: receiving information from a terminal device regarding a resolution of an analog-to-digital converter in the terminal device; sending an indication of a downlink transmission scheme for the terminal device to the terminal device based on the received information; and transmitting data to the terminal equipment according to the transmission scheme.

In one embodiment, sending the indication of the transmission scheme for the terminal device to the terminal device comprises: sending an indication of at least one of the following transmission parameters for the terminal device to the terminal device: a transmission diversity scheme, a modulation and coding scheme, and power allocation.

In another embodiment the method further comprises sending a request to said terminal device for said information about the resolution of an analog to digital converter in said terminal device. In one embodiment, the request is sent to the terminal device via an uplink grant message. In a further embodiment, the request indicates a transmission configuration of said information relating to a resolution of an analog-to-digital converter in said terminal device. In one embodiment, the network device sends the request to the terminal device in response to determining at least one of: the terminal device supports communication in a millimeter wave frequency band, the terminal device is operating in the millimeter wave frequency band, communication between the network device and the terminal device is switched from a first frequency band to a second frequency band, a transmission signal-to-noise ratio at the network device is higher than a first threshold, and reception performance of the terminal device is lower than a second threshold.

A second aspect of the present disclosure provides a method in a terminal device in a wireless communication system. The method comprises the following steps: sending information about the resolution of an analog-to-digital converter in the terminal device to a network device; receiving, from the network device, an indication of a downlink transmission scheme in response to the sending of the information; and receiving data from the network device in accordance with the received indication.

In one embodiment, said indication of the transmission scheme comprises information relating to at least one of the following transmission parameters: a transmission diversity scheme, a modulation and coding scheme, and power allocation.

In another embodiment, a terminal device sends information to the network device regarding the resolution of an analog-to-digital converter in the terminal device during a random access procedure.

In a further embodiment, the method further comprises receiving a request for said information relating to the resolution of an analog-to-digital converter in said terminal device from said network device. In one embodiment, the terminal device may receive the request from the network device via an uplink grant message. In another embodiment, the request indicates a transmission configuration for transmitting said information relating to the resolution of an analog-to-digital converter in said terminal device by said terminal device.

In some embodiments, the terminal device comprises a first analogue to digital converter for the first frequency band and a second analogue to digital converter for the second frequency band, the resolution of the first analogue to digital converter being different to the resolution of the second analogue to digital converter.

A third aspect of the present disclosure provides a network device. The network device includes a controller; and a transceiver coupled to the controller and configured by the controller to: receiving information from a terminal device regarding a resolution of an analog-to-digital converter in the terminal device; sending an indication of a downlink transmission scheme for the terminal device to the terminal device based on the received information; and transmitting data to the terminal equipment according to the transmission scheme.

A fourth aspect of the present disclosure provides a terminal device. The terminal device includes a controller, an analog-to-digital converter, and a transceiver. The transceiver is coupled to the controller and configured by the controller to: sending information about a resolution of at least one of the analog-to-digital converters to the network device; receiving, from the network device, an indication of a downlink transmission scheme in response to the sending of the information; and receiving data from the network device in accordance with the received indication.

A fifth aspect of the present disclosure provides a terminal device. The terminal device comprises a first analog-to-digital converter for a first frequency band and a second analog-to-digital converter for a second frequency band, the resolution of the first analog-to-digital converter being different from the resolution of the second analog-to-digital converter

As will be understood from the following description, according to an embodiment of the present disclosure, a network device may acquire information about an analog-to-digital converter in a terminal device from the terminal device and determine an appropriate transmission scheme for the terminal based on the information, thereby improving system performance.

It should be understood that the statements herein reciting aspects are not intended to limit the critical or essential features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become apparent from the following description.

Drawings

The objects, advantages and other features of the present invention will become more fully apparent from the following disclosure and appended claims. A non-limiting description of the preferred embodiments is given herein, by way of example only, with reference to the accompanying drawings, in which:

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

fig. 1B illustrates reception performance of terminal devices having different ADC resolutions in a wireless communication system;

fig. 2 shows a signaling diagram between a network device and a terminal device according to an embodiment of the disclosure;

fig. 3 shows a flow diagram of a method implemented at a network device, according to an embodiment of the present disclosure;

fig. 4 shows another signaling diagram between a network device and a terminal device according to an embodiment of the disclosure;

FIG. 5 shows a block diagram of a method implemented at a terminal device, according to an embodiment of the disclosure;

fig. 6 shows yet another signaling diagram between a network device and a terminal device according to an embodiment of the disclosure;

fig. 7 illustrates a block diagram of an apparatus implemented at a network device, according to an embodiment of the disclosure;

FIG. 8 shows a block diagram of an apparatus implemented at a terminal device, according to an embodiment of the present disclosure;

FIG. 9 illustrates a block diagram of an apparatus in accordance with certain embodiments of the present disclosure; and

fig. 10 shows the reception performance of the terminal device in the case where the ADC information is known and unknown to the network device.

Detailed Description

In the following description, numerous details are set forth for the purpose of explanation. However, one of ordinary skill in the art will realize that the invention may be practiced without the use of these specific details. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein.

It will be understood that the terms "first," "second," and the like, are used merely to distinguish one element from another. And in fact, a first element can also be referred to as a second element and vice versa. It will be further understood that the terms "comprises" and "comprising," when used in this specification, specify the presence of stated features, elements, functions, or components, but do not preclude the presence or addition of one or more other features, elements, functions, or components.

For ease of explanation, some embodiments of the present invention will be described herein in the context of millimeter wave communication and using terminology in long term evolution/long term evolution-advanced (LTE/LTE-a) as specified, for example, by the third generation partnership project (3GPP), however, as will be appreciated by those skilled in the art, embodiments of the present invention are in no way limited to wireless communication systems that follow wireless communication protocols specified by the 3GPP and are not limited to millimeter wave communication, but may be applied to any wireless communication system where similar problems exist, such as WLANs, or other communication systems developed in the future, and so forth.

Likewise, a terminal device in the present disclosure may be a User Equipment (UE), but may also be any terminal with wireless communication capabilities, including but not limited to, cell phones, computers, personal digital assistants, game consoles, wearable devices, in-vehicle communication devices, machine-to-machine communication devices, sensors, and the like. The term terminal device can be used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal, or wireless device. In addition, the network device may be a network Node, such as a Node B (or NB), a Base Transceiver Station (BTS), a Base Station (BS), or a base station subsystem (BSs), a relay, a remote radio head (RRF), AN Access Node (AN), AN Access Point (AP), and so on.

A schematic diagram of an example wireless communication system 100 in which methods of embodiments of the present disclosure can be implemented is shown in fig. 1A. The wireless communication system 100 may include one or more network devices 101. For example, in this example, the network device 101 may be embodied as a base station, such as an evolved node B (eNodeB, or eNB). It should be understood that the network device 101 may also be embodied in other forms, such as a Node B (or NB), a Base Transceiver Station (BTS), a Base Station (BS), or a base station subsystem (BSs), a repeater, etc. Network device 101 may provide radio connections for a plurality of

terminal devices

102 and 105 within its coverage area.

In one embodiment, the network device 101 may support multiple frequency bands. For example, the network device may operate in the current cellular communications band, and may also operate in the millimeter wave band to utilize greater bandwidth. Terminal devices may operate in a single or multiple frequency bands depending on their communication capabilities.

As described above, communication in the millimeter wave band requires an ADC having a higher sampling rate. Current systems present a number of challenges in supporting communication in the millimeter wave band. For example, in current cellular band communication systems, ADCs deployed at the receiver typically have high resolution. However, this type of ADC is not suitable for millimeter wave communication. The main reasons are two: (i) the high resolution ADCs used (e.g., 12-bit ADCs) are not capable of simultaneously providing a sufficiently high sampling rate to cope with the wide transmission bandwidth in millimeter wave communication systems; (ii) for UE devices, it is not affordable to deploy high-speed (e.g., a few G samples per second) and high-resolution ADCs.

To address the above issues, the UE may deploy a low resolution, high sampling rate ADC to receive wideband signals in the millimeter wave band. A low resolution ADC is less costly than a high resolution ADC and can provide a high sampling rate. However, this results in large quantization distortion.

It is proposed in this disclosure that in order to support cellular band communications and millimeter wave band communications, a terminal device may deploy two sets of ADCs with different resolutions (and sampling rates). For example, for communication in a low frequency band below 6GHz, the communication bandwidth is not too large and the corresponding sampling rate is not high, in which case a high resolution ADC may be used to quantize the received signal to ensure the quality of the sampled signal. To handle communication in the millimeter wave band of 28GHz or 60GHz, a high-speed low-resolution ADC may be employed to meet the sampling rate requirements for the received signal. Thus, the proposed solution achieves a compromise between hardware cost and performance.

For the equipment special for millimeter wave communication, in order to reduce the cost, only one set of high-speed low-resolution ADCs can be adopted to meet the requirement on the sampling rate of the received signal.

The inventor finds out through research that: when the terminal device uses ADCs of different resolutions, the received signal has a different signal to distortion and noise ratio (SDNR) and the SDNR performance difference varies with the transmission signal to noise ratio (SNR). In fig. 1B, the SDNR of a signal received by a terminal device (e.g., terminal 102) is shown using ADCs of different resolutions in the wireless communication system 100 of fig. 1A. In the example of fig. 1B, the communication system 100 is a single user-multiple input multiple output (SU-MIMO) Orthogonal Frequency Division Multiplexing (OFDM) millimeter wave communication system. However, as can be appreciated by those skilled in the art, embodiments of the present disclosure are not limited thereto.

In the example of fig. 1B, it is assumed that OFDM and SU-MIMO techniques are employed in the downlink, where the eNB has 16 antennas and the UE has a single antenna. The OFDM signal comprises 2048 sub-carriers in each of which information bits are mapped to a 16QAM constellation. In addition, assume that the input signal range of the ADC of the UE is-1V to 1V.

The received SDNR performance for 3-bit, 4-bit, 5-bit and 12-bit ADC resolutions are compared in fig. 1B. As shown in fig. 1B, in the low transmission SNR region, for example, the transmission SNR is lower than 10dB, the SDNR performance of the ADCs with different resolutions are close to each other. This result means that deploying a low resolution ADC at the receiver does not result in a significant performance penalty for noise limited scenarios. Thus, deploying a low resolution ADC in this case may advantageously result in a reduction in hardware cost. For high SNR regions, such as those shown with SNR higher than 10dB, the quantization distortion introduced by the ADC becomes a major performance burden. In order for a UE with a low resolution ADC to obtain the same SNDR as a high ADC resolution, it is necessary to transmit with a larger transmission power on the base station side. In other words, for a particular modulation coding scheme, the eNB will need to employ higher transmit power compared to the high resolution ADC scenario in order to achieve the required received SDNR. For example, if the UE deploys an ADC with 4-bit resolution, the transmit SNR on the base station side needs 17.5dB in order to achieve 15dB SDNR on the UE side. This is 2.5dB higher than the transmit power required by a UE with an ADC of 12 bit resolution.

Therefore, it is desirable for the base station to be able to design an adaptive transmission scheme according to the ADC resolution of the UE. However, there is currently no mechanism for supporting the exchange of ADC information between the UE and the eNB.

It is proposed in the present disclosure that a terminal device reports information about the resolution of its ADC to a network device to enable the network device to determine transmission parameters for the terminal device, e.g. transmit power, diversity scheme, modulation coding scheme, etc. Wherein determining the diversity scheme may comprise, for example, determining whether Beamforming (BF) is employed for transmission by the terminal device.

For millimeter-wave band communications, the UE may deploy relatively low-resolution ADCs (such as 4-bit or 5-bit resolutions), while for low-band communications, the UE may maintain high-resolution ADCs. The main benefits are at least represented in the following three aspects: (i) with a lower resolution ADC, a much higher sampling rate can be provided, which is particularly suitable for millimeter wave communication with a large transmission bandwidth; (ii) by deploying ADCs with relatively low resolution in the millimeter wave frequency band, hardware costs are reduced to a level that can be borne by UE devices; (iii) for low frequency band communication, a high resolution ADC is maintained so that a sampled signal with low quantization distortion can still be provided.

According to an embodiment of the present disclosure, in order to perform downlink data transmission in a millimeter wave band, a base station may acquire resolution information of an ADC disposed on a UE device side. Based on the resolution information, the base station may perform an appropriate transmission scheme for downlink data transmission.

A schematic signaling diagram for implementing this ADC resolution information acquisition is shown in fig. 2. For convenience of description, an interactive process between the network device 101 and the terminal device 102 will be described. At 201, the terminal device 102 sends a message to the network device 101, including information of its ADC (e.g., information about the resolution of the ADC), which may be carried in uplink signaling.

At 202, using the ADC information from terminal device 102, network device 101 designs an appropriate transmission scheme, such as beamforming, power allocation, etc., appropriate for the ADC resolution of terminal device 102.

At 203, the network device 101 transmits data to the terminal device 102 using the designed transmission scheme. This may include, for example, sending an indication of the transmission format and the data transmitted in accordance with that format to the terminal device 102.

Referring now to fig. 3, a flow diagram of a method 300 implemented at a network device in a wireless communication network (e.g., network 100 in fig. 1A) is shown, in accordance with an embodiment of the present disclosure. The method 300 may be performed by, for example, the network device 101 in fig. 1A, which may be, for example, a base station. For ease of description, the method 300 is described below in conjunction with FIG. 1A.

As shown in fig. 3, at block 310, network device 101 receives information from a terminal device (e.g., UE 102 in fig. 1A) regarding the resolution of an analog-to-digital converter (ADC) in the terminal device. In one embodiment, the received information related to the resolution of the ADC may directly indicate the resolution of the ADC, e.g., a 4-bit resolution, a 12-bit resolution, etc. In another embodiment, the information may indicate an index of a certain resolution from a set of predetermined resolutions, for example a resolution with an index of 1. In yet another embodiment, the information may indicate a level of resolution, e.g., low, medium, or high resolution.

At block 320, based on the information received at block 310, the network device 101 sends an indication of a downlink transmission scheme for the terminal device. The transmission scheme may include, for example, but is not limited to, one or more of a modulation and coding scheme, a diversity scheme, a power allocation. The indication may be sent, for example, via a downlink grant message. In one embodiment, network device 101 may determine whether to employ beamforming in a transmission for a terminal device and/or determine a transmit power for the terminal device based on information received from the terminal device regarding the ADC.

At block 330, the network device 101 transmits data to the terminal device according to the transmission scheme.

According to the method 300, the network device can obtain the ADC resolution information of the terminal device, so that a suitable transmission scheme for the terminal device can be determined, the performance of the receiving end is ensured, unnecessary retransmission is avoided, and system resources are saved.

In one embodiment, the information related to the ADC received by the network device at block 310 may be sent by the terminal device based on a request from the network device. In this embodiment, the method 300 may further include block 340 in which the network device sends a request to the terminal device for information relating to the resolution of the analog-to-digital converter in the terminal device.

As can be appreciated by those skilled in the art, embodiments of the present disclosure are not limited to sending the request in any particular format. For example only, in one embodiment, the network device may send the request via an uplink grant message of the physical layer. In another embodiment, the network device may send the request through other physical layer or higher layer signaling.

In one embodiment, the request indicates a transmission configuration of information related to a resolution of the ADC. For example, the request indicates resources (e.g., time-frequency resources) to transmit information about the ADC resolution by the terminal device. In another embodiment, the resource indication may be omitted, alternatively the terminal device may implicitly determine the resources for transmitting information about the ADC resolution according to a predetermined rule. In another embodiment, the transmission configuration may also indicate a transmission format. In a further embodiment, the request may also indicate the frequency band for which the terminal device is required to transmit information for the ADC of that frequency band.

In one embodiment, the network device 101 may send a request for ADC resolution to the terminal device at block 340 in response to determining that the terminal device supports communication in the millimeter wave frequency band. Whereas for terminal devices that do not support millimeter wave communication, network device 101 may assume that it employs a conventional ADC.

In another embodiment, the network device 101 may send a request for ADC resolution to the terminal device in response to determining that communication with the terminal device is in the millimeter wave frequency band. Alternatively, in another embodiment, the network device 101 may send a request for ADC resolution to the terminal device in response to determining a switch in the operating frequency band, e.g., a switch in communication with the terminal device from a first frequency band to a second frequency band. The first frequency band may be, for example, a cellular communication frequency band, and the second frequency band may be, for example, a millimeter wave frequency band. It will be understood by those skilled in the art that embodiments of the present disclosure are not limited to the first frequency band and the second frequency band so configured.

In yet another embodiment, the network device 101 may send an ADC resolution request to the terminal device only if its transmit signal-to-noise ratio is above a predetermined signal-to-noise ratio threshold. Based on the SDNR performance results of fig. 1B, it can be found that the ADC resolution has little impact on performance for low transmit SNRs. Thus, the network device can reduce transmission of unnecessary ADC resolution information using this characteristic.

Alternatively or additionally, in another embodiment, the network device may request to obtain ADC resolution information for the terminal device when it is determined that the reception performance of the terminal is below a predetermined performance threshold to help determine the cause of the diagnosed poor reception performance. The network device may determine the reception performance of the terminal, for example, through feedback of the terminal, or may determine the reception performance of the terminal based on a request rate for retransmission.

A signaling diagram for triggering the reporting of ADC resolution information by a base station, according to one embodiment of a method 300 of the present disclosure, is shown in fig. 4. As shown in fig. 4, at 401, network device 101 sends downlink signaling to trigger reporting of ADC information by terminal device 102, e.g., as the transmission band changes. The signaling may contain configurations for the UE to report the ADC information, e.g., radio resources (e.g., time-frequency resources) for ADC information reporting.

At 402, based on the received trigger signaling, the terminal device 102 reports its ADC information to the network device 101; the ADC information may include, but is not limited to, information related to ADC resolution. In one embodiment, the ADC information may also include, for example, sample rate information, and/or other ADC parameter information.

At 403, network device 101 may determine an optimized transmission scheme. At 404, data transmission to the terminal device 102 is performed based on the determined transmission scheme. For example, at 404, network device 101 may perform the acts of

blocks

320 and 330.

The above embodiments provide a signaling procedure to support ADC resolution information reporting from the terminal device to the network device, enabling the network device to perform an adaptive downlink transmission scheme according to the resolution of the ADC at the terminal side. Without this mechanism, the terminal device 102 would not know when and how to report this important information to the base station, nor could the base station perform adaptive transmission scheme adjustments, and thus lead to performance loss.

A flow chart of a method 500 at a terminal device in a wireless communication network according to an embodiment of the present disclosure is described below with reference to fig. 5. The method 500 may be performed by, for example, any of the UEs 102-105 in fig. 1A. In the following description, for convenience of description, the method 500 is described with reference to fig. 1A.

As shown in fig. 5, at block 510, terminal device 102 sends information regarding the resolution of the ADC in the terminal device to a network device (e.g., network device 101 in fig. 1A). In one embodiment, the network device may be the network device 101 implementing the method 300. In this embodiment, the transmission by terminal device 102 at block 510 corresponds to the reception by network device 101 at block 310, and thus the ADC-related information described in connection with method 300 is equally applicable here. For example, the information regarding the ADC sent at block 510 may directly indicate the resolution of the ADC, or indicate an index or level of the ADC resolution.

In response to the transmission of the information related to the resolution of the ADC, the terminal device 102 receives an indication of the transmission scheme from the network device 101 at block 520. In one embodiment, the indication of the transmission scheme comprises information on at least one of the following transmission parameters: transmit diversity schemes, modulation and coding schemes, and power allocation. At block 530, the terminal device 102 receives data from the network device 101 according to the received indication of the transmission scheme.

With the method 500, a terminal device can report information about the resolution of its ADC to a network device. In this way, the network device can take this information into account when determining the downlink transmission scheme to meet the performance requirements of the terminal device.

In one embodiment, the terminal device's transmission at block 510 is triggered by the network device 101. For example, at block 505, prior to block 510, terminal device 102 receives a request from network device 101 for resolution information for an ADC of terminal device 102. As described previously in connection with method 300, the network device 101 may send the request to the terminal device in response to determining one or more of: the terminal device supports or is operating in the millimeter wave frequency band, the network device switches communication with the terminal device from a first frequency band to a second frequency band, the transmit signal-to-noise ratio at the network device 101 is above a first threshold, and the reception performance of the terminal device 102 is below a second threshold.

By way of example and not limitation, in one embodiment, the terminal device may receive a request for ADC resolution information from the network device 101 in block 540 via an uplink grant message. In a further embodiment, the request may indicate a transmission configuration of information relating to a resolution of an ADC in the terminal device. For example, the transmission configuration may include a radio resource for transmitting, by the terminal device, information on a resolution of an ADC in the terminal device. As will be appreciated by those skilled in the art, in some embodiments the request may not explicitly indicate the resource, but instead the terminal device may determine the resource according to a predetermined rule. In another embodiment, the transmission configuration may also include a transmission format of information related to the resolution of the ADC.

Alternatively, in another embodiment, the terminal device 102 may autonomously send information about its ADC resolution to the network device. For example, the terminal device 102 may send information regarding the resolution of an ADC in the terminal device 102 to a network device during a random access procedure. To report information related to ADC resolution during the random access procedure, an enhanced random access procedure may be employed, wherein the information related to ADC resolution is transmitted via messages (e.g., random access preamble, and/or message 3) exchanged during the random access procedure.

A schematic signaling diagram of a UE reporting ADC information during a random access procedure according to one embodiment of the method 500 of the present disclosure is shown in fig. 6. In the example of fig. 6, the terminal device 102 transmits a random access preamble to the network device 101 at 601, and receives a random access response from the network device 101 at 602.

Operations

601 and 602 may employ any currently known or future established random access procedure, such as may be in compliance with the specifications for random access in the 3GPP LTE specifications.

At 603, terminal device 102 sends message 3 (alternatively referred to as Msg 3) to network device 101. This message 3 is different from the message 3 in the conventional random access procedure. Information about the ADC, for example about the resolution of the ADC, is carried in this information 3. In one embodiment, this message 3 may also include information about the sampling rate of the ADC.

At 604, network device 101 sends a contention resolution message, message 4, to terminal device 102. In one embodiment, this message 4 may be the same as a conventional random access contention resolution message (e.g., in 3GPP LTE or LTE-a). In another embodiment, in the contention resolution message sent at 604, the network device 101 may also indicate to the terminal device 102 additional information, for example regarding the transmission scheme to be subsequently used for that terminal device 102 in the downlink data transmission. The transmission scheme includes, for example, transmission power, modulation and coding format, whether to employ a transmit diversity scheme, what diversity scheme is employed, and the like.

It should be noted that fig. 6 is only an example of transmitting information related to the ADC in the random access procedure. In another example, the terminal device 102 may communicate information related to the ADC through the random access preamble sent in 601. For example, terminal device 102 may select a preamble to transmit from a different set of preambles depending on its ADC resolution to indicate to network device 101 the resolution of its ADC.

In one embodiment, the random access procedure in fig. 6 may be terminal device 102 initiated. In another embodiment, the random access procedure may be triggered by the network device 101, and in this embodiment, the network device 101 may send a request for information relating to the ADC to the terminal device 102 when the random access procedure is triggered.

In some embodiments, the terminal device transmitting the information on the ADC resolution may include a first ADC for the first frequency band and a second ADC for the second frequency band, the resolution of the first ADC being different from the resolution of the second ADC. In one embodiment, the terminal device may report the resolution of the ADC it is to use based on the frequency band currently operating or to which it is to be handed over. In another embodiment, the terminal device may report its information for the ADCs of both frequency bands (e.g., resolution information of the ADCs) at the same time, e.g., at random access. In a further embodiment, the terminal device may also transmit information for the requested ADC for the particular frequency band upon request from the network device.

In other embodiments, the terminal device may include more or fewer ADCs as well. For example, a terminal device dedicated to a particular frequency band may include only one ADC. In addition, in one embodiment, a terminal device capable of operating in more than two frequency bands may also include more than two ADCs for the frequency bands, respectively. In another embodiment, the same ADC may be used for more than one frequency band.

Fig. 7 illustrates a block diagram of an apparatus 700 according to certain embodiments of the present disclosure. The apparatus 700 may be implemented, for example, on the network device 101 side shown in fig. 1A. As shown in fig. 7, the apparatus 700 includes: a receiving unit 701 configured to receive information on a resolution of an ADC in a terminal device from the terminal device; a first sending unit 702 configured to send, to the terminal device, an indication of a downlink transmission scheme for the terminal device based on the received information; and a second sending unit 703 configured to transmit data to the terminal device according to the transmission scheme.

In some embodiments, the indication of the transmission scheme sent by the sending unit 702 to the terminal device may comprise an indication of at least one of the following transmission parameters: a transmit diversity scheme (e.g., whether transmit diversity is employed, what transmit diversity is employed, etc.), a modulation and coding scheme, and a power allocation. Optionally, in an embodiment, the sending unit 702 may send the indication of the transmission scheme through a downlink grant message. Alternatively or additionally, in another embodiment, the sending unit 702 may send the indication of the transmission scheme by message 4 of a random access procedure. As can be appreciated by those skilled in the art, embodiments of the present disclosure are not limited to sending the indication of the transmission scheme in any particular message and format.

In still other embodiments, the apparatus 700 may further include a third sending unit configured to send a request to the terminal device for information about a resolution of an ADC in the terminal device. In one embodiment, the third transmitting unit may be configured to transmit the request to the terminal device through an uplink grant message.

Optionally, in one embodiment, the request may indicate a transmission configuration of information relating to the resolution of the ADC in the terminal device, such as, but not limited to, radio resources and/or transport format used for the transmission of the message.

In one embodiment, the third transmitting unit may transmit the request to the terminal device in response to determining at least one of: the terminal equipment supports communication in a millimeter wave frequency band; the terminal device is operating in a millimeter wave frequency band; the communication between the network equipment and the terminal equipment is switched from a first frequency band to a second frequency band; a transmit signal-to-noise ratio at the network device is above a first threshold; and the reception performance of the terminal device is lower than a second threshold.

Fig. 8 illustrates a block diagram of an apparatus 800 according to certain embodiments of the present disclosure. The apparatus 800 may be implemented, for example, on the terminal device 102 side shown in fig. 1A. As shown, the apparatus 800 includes: a transmitting unit 801 configured to transmit information on the resolution of the ADC in the terminal apparatus 102 to a network apparatus (e.g., the network apparatus 101 in fig. 1A); a first receiving unit 802 configured to receive, from the network device, an indication of a downlink transmission scheme in response to the sending of the information; and a second receiving unit 803 configured to receive data from the network device according to the received indication.

In one embodiment, the transmitting unit 801 may be configured to transmit information related to the resolution of the ADC in the terminal device 102 to the network device during the random access procedure.

In another embodiment, the indication of the downlink transmission scheme received by the first receiving unit 802 may comprise information on at least one of the following transmission parameters: a transmission diversity scheme, a modulation and coding scheme, and power allocation.

Optionally, in an embodiment, the apparatus 800 may further include a third receiving unit configured to receive, from the network device, a request for the information related to the resolution of the analog-to-digital converter in the terminal device 102. And the transmission unit 801 may transmit information on the resolution of the ADC in the terminal apparatus 102 in response to the request.

In one embodiment, the third receiving unit may receive the request from the network device through an uplink grant message. In another embodiment, the request may indicate a transmission configuration, e.g. format or/and radio resources, or/and frequency band for transmitting information by the terminal device regarding the resolution of the ADC in the terminal device.

In some embodiments, the terminal device may comprise a first analogue to digital converter for the first frequency band and a second analogue to digital converter for the second frequency band, the resolution of the first analogue to digital converter being different to the resolution of the second analogue to digital converter.

It should be understood that each unit recited in the apparatus 700 and the apparatus 800 corresponds to each step in the

methods

300 and 500 described with reference to fig. 3 and 5, respectively. Therefore, the operations and features described above in connection with fig. 3 to 5 are also applicable to the apparatus 700 and the apparatus 800 and the units included therein, and have the same effects, and detailed details are not repeated.

The units included in the apparatus 700 and the apparatus 800 may be implemented in various ways, including software, hardware, firmware, or any combination thereof. In one embodiment, one or more of the units may be implemented using software and/or firmware, such as machine executable instructions stored on a storage medium. In addition to, or in the alternative to, machine-executable instructions, some or all of the elements in apparatus 700 and apparatus 800 may be implemented, at least in part, by one or more hardware logic components. By way of example, and not limitation, exemplary types of hardware logic components that may be used include Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Application Specific Standards (ASSPs), systems on a chip (SOCs), Complex Programmable Logic Devices (CPLDs), and so forth.

As described above, in some embodiments, the above-described flows, methods or processes may be implemented by hardware in a network device or a terminal device. For example, a network device or a terminal device may implement

methods

300 and 500 with its transmitter, receiver, transceiver, and/or processor or controller. Fig. 9 illustrates a block diagram of a device 900 suitable for implementing embodiments of the present disclosure. Device 900 may be used to implement a network device, such as network device 101 shown in FIG. 1A; and/or to implement a terminal device, such as the first terminal device 102 shown in fig. 1A.

As shown in the example of fig. 9, the device 900 includes a controller 910. The controller 910 controls the operation and functions of the device 900. For example, in certain embodiments, the controller 910 may perform various operations by way of instructions 930 stored in a memory 920 coupled thereto. The memory 920 may be of any suitable type suitable to the local technical environment and may be implemented using any suitable data storage technology, including but not limited to semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems. Although only a single memory unit is illustrated in FIG. 9, there may be multiple physically distinct memory units within device 900.

The controller 910 may be of any suitable type suitable to the local technical environment, and may include, but is not limited to, one or more of general purpose computers, special purpose computers, microcontrollers, digital signal controllers (DSPs), and controller-based multi-core controller architectures. The device 900 may also include a plurality of controllers 910. The controller 910 is coupled to a transceiver 940, and the transceiver 940 may enable receiving and transmitting information via one or more antennas 950 and/or other components.

When device 900 is acting as network device 101, controller 910 and transceiver 940 may operate in conjunction to implement method 300 described above with reference to fig. 3.

The device 900, when acting as the first terminal device 102, may further comprise an analog-to-digital converter (not shown in the figure). The controller 910 and the transceiver 940 of the device 900 may operate cooperatively to implement the method 500 described above with reference to fig. 5 to transmit information regarding at least one of its analog-to-digital converters to a network device.

All of the features described above with reference to fig. 3 and 5 apply to the apparatus 900 and are not described in detail herein.

The performance gains that can be obtained using embodiments of the present disclosure in one example use scenario are illustrated below in conjunction with fig. 10. In this example scenario, it is assumed that embodiments of the present disclosure are implemented in the wireless communication system 100 of fig. 1A, and that the system 100 is a multi-user-multiple input multiple output (MU-MIMO) OFDM millimeter wave communication system.

In this example, consider the use of OFDM and MU-MIMO techniques in the downlink, and where network device 101 is an eNB with 16 antennas. The eNB serves 4 single antenna UEs simultaneously. The OFDM signal comprises 2048 sub-carriers in each of which information bits are mapped to a 16QAM constellation. The transmit signal-to-noise ratio (SNR) of the eNB is assumed to be limited to 25 dB. In this example, assume that each UE deploys a 4-bit ADC, and the input signal range of the UE's ADC is-1V to 1V.

In this example, to address co-channel interference, consider employing a zero-forcing beamforming technique. In addition, the eNB also allocates transmission power for each UE based on a specific quasi-ranging according to the ADC resolution of the UE. In addition, the coding and modulation schemes may be adaptively adjusted based on the received SDNR. Therefore, in the computer simulation, the reception SDNR target of the UE is set first. The eNB then selects an appropriate transmission scheme to achieve the predetermined SDNR target while using as little transmit power as possible to reduce power consumption.

Under the conditions of this system configuration and simulation setup, the SDNR performance curve as shown in fig. 10 was obtained. Where the SDNR performance was compared in two cases:

case 1: with the mechanism proposed by embodiments of the present disclosure, the eNB learns the resolution of the ADC deployed at the UE;

case 2: without the mechanism proposed by embodiments of the present disclosure, the resolution of the ADC deployed at the UE is unknown to the eNB. In this case, the eNB assumes that the UE deploys a 12-bit ADC, as in the conventional scenario.

The line indicated by a legend 1001 in fig. 10 represents the expected value of the worst received SDNR when the eNB can know the ADC resolution information. This curve is used as a baseline to show whether the target SDNR for the UE is reached. In particular, if the worst received SNR for the UE is above the curve, the target received SDNR for the UE is deemed to be reached, otherwise, the target received SDNR for the UE is deemed to not be reached. The line indicated by a legend 1002 represents the computer simulation results corresponding to case 1, and the line indicated by a legend 1003 in fig. 10 represents the computer simulation results corresponding to case 2.

As can be seen from fig. 10, for the case where the ADC information is unknown (i.e., case 2), on average, the target reception SDNR cannot be reached. As can be seen from fig. 10, in addition, the performance loss is not significant when the target reception SDNR is small. This is because ADCs of various resolutions have similar performance when the SNR is not high (e.g., when the SNR is below 10 dB) (see the results of fig. 1B). However, as the target reception SDNR increases, the transmission SNR should be increased. To achieve the target receive SDNR, the eNB should use more transmit power for UEs deploying 4-bit ADCs. Whereas for case 2, the eNB overestimates the UE's capabilities (assuming it has a 12-bit resolution ADC) and erroneously saves power, resulting in a performance loss on the UE side.

Also, as shown in fig. 10, when the target reception SDNR is set to 16dB, there is a difference of 2dB on average between the target reception SNR and the worst SDNR obtained in case 2. As is known, the coding and modulation schemes may be adapted to receive SDNR. This means that for a fixed modulation and coding scheme adapted to receive SDNR, there will be a large bit error rate when the eNB does not know the ADC resolution of the UE. Since in this case the received SDNR is 2dB lower than the predetermined target SNR. However, for case 1, this phenomenon does not exist. Since the eNB knows the ADC information of the UE based on the proposed mechanism, the transmit power is adjusted.

In general, the various example embodiments of this disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Certain aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While aspects of embodiments of the disclosure have been illustrated or described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

By way of example, embodiments of the disclosure may also be described in the context of machine-executable instructions, such as those included in program modules, being executed in devices on target real or virtual processors. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or divided between program modules as described. Machine-executable instructions for program modules may be executed within local or distributed devices. In a distributed facility, program modules may be located in both local and remote memory storage media.

Computer program code for implementing the methods of the present disclosure may be written in one or more programming languages. These computer program codes may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the computer or other programmable data processing apparatus, cause the functions/acts specified in the flowchart and/or block diagram block or blocks to be performed. The program code may execute entirely on the computer, partly on the computer, as a stand-alone software package, partly on the computer and partly on a remote computer or entirely on the remote computer or server.

In the context of this disclosure, a machine-readable medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More detailed examples of a machine-readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical storage device, a magnetic storage device, or any suitable combination thereof.

Additionally, 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 or parallel processing may be beneficial. Likewise, while the above discussion contains certain specific implementation details, this should not be construed as limiting the scope of any invention or claims, but rather as describing particular embodiments that may be directed to particular inventions. 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.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A method performed in a network device in a wireless communication system, comprising:

transmitting a request to a terminal device for information on a resolution of one of a first analog-to-digital converter for a first frequency band and a second analog-to-digital converter for a second frequency band in the terminal device, the first frequency band being lower than the second frequency band and the resolution of the first analog-to-digital converter being higher than the resolution of the second analog-to-digital converter;

receiving information from the terminal device regarding a resolution of the one of the first and second analog-to-digital converters;

sending an indication of a downlink transmission scheme for the terminal device to the terminal device based on the received information; and

and transmitting data to the terminal equipment according to the transmission scheme.

2. The method of claim 1, wherein sending the terminal device an indication of a transmission scheme for the terminal device comprises:

sending, to the terminal device, an indication of at least one of the following transmission parameters for the terminal device: a transmission diversity scheme, a modulation and coding scheme, and power allocation.

3. The method of claim 1, wherein sending the request comprises:

sending the request to the terminal device via an uplink grant message.

4. The method of claim 1, wherein the request indicates a transmission configuration of the information relating to a resolution of the one of the first and second analog-to-digital converters in the terminal device.

5. The method of claim 1, wherein sending the request comprises sending the request to the terminal device in response to determining at least one of:

the terminal equipment supports communication in a millimeter wave frequency band;

the terminal device is operating in a millimeter wave frequency band;

the communication between the network equipment and the terminal equipment is switched from the first frequency band to the second frequency band;

a transmit signal-to-noise ratio at the network device is above a first threshold; and

the receiving performance of the terminal device is lower than a second threshold.

6. A method performed in a terminal device in a wireless communication system, comprising:

receiving, from a network device, a request for information on a resolution of one of a first analog-to-digital converter for a first frequency band and a second analog-to-digital converter for a second frequency band in the terminal device, the first frequency band being lower than the second frequency band, and a resolution of the first analog-to-digital converter being higher than a resolution of the second analog-to-digital converter;

sending information to the network device about a resolution of the one of the first and second analog-to-digital converters;

receiving, from the network device, an indication of a downlink transmission scheme in response to the sending of the information; and

receiving data from the network device in accordance with the received indication.

7. The method according to claim 6, wherein the indication of transmission scheme comprises information on at least one of the following transmission parameters:

a scheme of a transmission diversity is used for the transmission,

modulation and coding scheme, and

and (4) allocating power.

8. The method of claim 6, wherein receiving the request comprises:

receiving the request from the network device via an uplink grant message.

9. The method of claim 6, wherein the request indicates a transmission configuration for transmitting, by the terminal device, the information relating to the resolution of the one of the first and second analogue-to-digital converters in the terminal device.

10. The method of claim 6, wherein sending the information about the resolution of the one of the first and second analog-to-digital converters in the terminal device to the network device comprises:

sending the information about the resolution of the one of the first and second analogue to digital converters in the terminal device to the network device during a random access procedure.

11. A network device, comprising:

a controller; and

a transceiver coupled to and configured by the controller to:

12. The network device of claim 11, wherein the transceiver is further configured to send the indication of the transmission scheme for the terminal device by sending the terminal device an indication of at least one of the following transmission parameters for the terminal device: a transmission diversity scheme, a modulation and coding scheme, and power allocation.

13. The network device of claim 11, wherein the transceiver is further configured to:

sending the request to the terminal device via an uplink grant message.

14. The network device of claim 11, wherein the request indicates a transmission configuration of the information related to a resolution of the one of the first and second analog-to-digital converters in the terminal device.

15. The network device of claim 11, wherein the transceiver is further configured to send the request to the terminal device in response to determining at least one of:

the terminal device is operating in a millimeter wave frequency band;

16. A terminal device, comprising:

a controller;

a first analog-to-digital converter for a first frequency band and a second analog-to-digital converter for a second frequency band, the first frequency band being lower than the second frequency band, and a resolution of the first analog-to-digital converter being higher than a resolution of the second analog-to-digital converter; and

a transceiver coupled to and configured by the controller to:

receiving, from a network device, a request for information relating to a resolution of one of the first and second analog-to-digital converters;

17. The terminal device according to claim 16, wherein the indication of transmission scheme comprises information on at least one of the following transmission parameters:

a scheme of a transmission diversity is used for the transmission,

modulation and coding scheme, and

and (4) power distribution.

18. The terminal device of claim 16, wherein the transceiver is further configured to receive the request from the network device through an uplink grant message.

19. The terminal device of claim 16, wherein the request indicates a transmission configuration for transmitting the information related to the resolution of the one of the first and second analog-to-digital converters by the terminal device.

20. The terminal device of claim 16, wherein the transceiver is further configured to:

sending the information related to the resolution of the one of the first and second analog-to-digital converters to the network device during a random access procedure.