CN114731519A

CN114731519A - Non-orthogonal multiple access method, base station and user equipment

Info

Publication number: CN114731519A
Application number: CN202080063627.5A
Authority: CN
Inventors: 萨拉赫·埃丁·哈伊里; 穆罕默德·阿萨德
Original assignee: Central Polytechnic Higher Institute Of Electric Power Paris; Tcl Communications Co ltd
Current assignee: Central Polytechnic Higher Institute Of Electric Power Paris; Tcl Communications Co ltd
Priority date: 2019-10-09
Filing date: 2020-09-29
Publication date: 2022-07-08
Also published as: WO2021068808A1

Abstract

A non-orthogonal multiple access method is executed in a system with a central controller, a plurality of Transmission and Reception Points (TRPs) and User Equipment (UE) in a Cloud Radio Access Network (CRAN). The user equipment performs an open loop power control method to determine a power domain characteristic value based on macro diversity associated with the UE. The central controller acquires signal quality of the UE from power domain characteristic values of the UE, classifies the UE according to the signal quality of the UE, and distinguishes between different practices as to whether a multi-user interference cancellation scheme is used in the signal decoding in decoding wireless signals for the classified UE.

Description

Non-orthogonal multiple access method, base station and user equipment

Technical Field

The present disclosure relates to the field of communication systems, and more particularly to non-orthogonal multiple access (NOMA) in a high connection density Cloud Radio Access Network (CRAN).

Background

Standards and techniques for wireless communication systems, such as third-generation (3G) mobile phones, are well known. Such 3G standards and technologies are developed by the Third Generation Partnership Project (3 GPP). Third generation wireless communications are widely developed to support giant cell mobile phone communications. Communication systems and networks have evolved into a broadband and mobile system. In a cellular Radio communication system, a User Equipment (UE) is connected to a Radio Access Network (RAN) over a Radio link. The RAN includes a set of Base Stations (BS) that provide radio links for user equipment in the cells covered by the Base stations, and an interface to the Core Network (CN) that provides overall network control. It will be appreciated that the RAN and CN each perform functions related to the overall network. The third generation partnership project has developed a so-called Long Term Evolution (LTE) System, i.e., Evolved Universal Mobile telecommunications System terrestrial Radio Access Network (E-UTRAN), for Mobile Access networks, in which one or more macro cells are supported by a base station called Evolved NodeB (eNodeB or eNB). Recently, LTE is further evolving towards so-called 5G or New Radio (NR) systems, where one or more cells are supported by a base station called a gNB.

With the proliferation of smart devices and the emergence of new services with high capacity requirements, wireless networks are facing a whole new set of challenges in technology and business models.

In fact, the next generation mobile network must meet diversified requirements through different Key Performance Indicators (KPIs), and the 5G mobile network can implement three major classes of emerging services: enhanced mobile broadband (eMBB), ultra-reliable and low-latency communication (uRLLC), and massive machine type communication (mMTC).

The current mobile network architecture has proven insufficient to meet the requirements of 5G services. In fact, previous generations of networks were designed specifically to meet the requirements of voice and traditional mobile broadband services. Since 5G networks are expected to provide diverse services, support existing standards such as LTE and Wireless Local Area Networks (WLANs), and coordinate different station types, a more flexible and distributed service-driven architecture is needed.

Disclosure of Invention

An object of the present disclosure is to propose a NOMA method, a base station and a user equipment.

A first aspect of the present disclosure provides a non-orthogonal multiple access (NOMA) method, executable in a central controller of a base station, comprising:

receiving wireless signals from a set of V User Equipments (UEs) through a set of M distributed radio nodes, wherein V and M are positive integers;

estimating a signal quality for each user equipment in the set of V user equipments;

classifying the set of V user equipments into a high signal quality sub-group and a low signal quality sub-group according to the estimated signal quality of each user equipment in the set of V user equipments; and

using a multi-user interference cancellation scheme to decode wireless signals of user equipments belonging to the low signal quality sub-group; and

decoding wireless signals of user equipments belonging to the high signal quality subgroup without using the multi-user interference cancellation scheme.

A second aspect of the present disclosure provides a non-orthogonal multiple access method, which may be implemented in a User Equipment (UE), and includes:

obtaining a plurality of power domain measurements of wireless signals of a set of distributed radio nodes;

obtaining a power domain characteristic value of the user equipment from the plurality of power domain measurement values; and

transmitting the power domain characteristic value for a multiple access procedure associated with the user equipment.

A third aspect of the present disclosure provides a base station, comprising:

a transceiver; and

a processor coupled to the transceiver and configured to perform the following steps, comprising:

decoding wireless signals of user equipments belonging to the low signal quality subgroup using a multi-user interference cancellation scheme; and

A fourth aspect of the present disclosure provides a User Equipment (UE), comprising:

a transceiver; and

The disclosed method may be implemented in a chip. The chip may comprise a processor configured to invoke and run a computer program stored in a memory to cause a device in which the chip is installed to perform the disclosed method.

The disclosed methods may be programmed as computer-executable instructions stored in a non-transitory computer-readable medium. A non-transitory computer readable medium that, when loaded into a computer, instructs the processor of the computer to perform the disclosed method.

The non-transitory computer readable medium may include at least one from the group of: hard disks, CD-ROMs, optical storage devices, magnetic storage devices, Read-Only memories, Programmable Read-Only memories, Erasable Programmable Read-Only memories (EPROMs), and flash memories.

The disclosed methods may be programmed as a computer program product for causing a computer to perform the disclosed methods.

The disclosed methods may be programmed as a computer program that causes a computer to perform the disclosed methods.

The beneficial effects are as follows:

the invention realizes the grant-free (grant-free) uplink power domain NOMA in the ultra-dense CRAN, and simultaneously improves the network performance. The disclosed invention may be implemented by a computer program, executable by a computerized device, and may be stored in a memory or storage medium, which when loaded into the device instructs a processor of the device to perform the method.

The present invention optimizes the combination of the Cloud Radio Access Network (CRAN) and NOMA to address the shortcomings of the two technologies and enable unlicensed access to UEs (e.g., MTC devices). A key part of the present invention includes exploiting the considerable Macro diversity (Macro diversity) of the CRAN architecture to address the difficulties of the power domain NOMA. The proposed power control and detection weight optimization are both based on the CRAN macro-diversity. The proposed detection weight optimization may avoid the need for power control to be allocated by the network and optimize the NOMA receiver by reducing the effort of interference cancellation.

Drawings

In order to more clearly illustrate the embodiments of the present disclosure or the related art, the embodiments will be briefly described below. It is clear that the figures are only some embodiments of the present disclosure, from which other numbers can be obtained by a person having ordinary skill in the art without paying for the premises.

Fig. 1 is a schematic diagram showing a telecommunications system.

Fig. 2 is a schematic diagram showing a CRAN with a pool of baseband units, remote radio heads, and UEs.

Fig. 3 is a schematic diagram showing a NOMA method performed at the UE side according to an embodiment of the present disclosure.

Fig. 4 is a diagram illustrating a NOMA method performed at an uplink receiving end according to an embodiment of the present disclosure.

Fig. 5 is a diagram showing the effect of the proposed open-loop power control method on the Spectral Efficiency (SE) of different priority/reliability (P/R) coefficients.

Fig. 6 is a diagram illustrating a NOMA method performed at an uplink receiving end according to another embodiment of the present disclosure.

Fig. 7 is a diagram showing bit error rate as a function of SIC decoding rank for two active UE devices.

Fig. 8 is a diagram showing bit error rate as a function of SIC decoding rank for a UE device with four active UEs.

Fig. 9 is a block diagram illustrating a wireless communication system according to an embodiment of the present disclosure.

Detailed Description

Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings, in conjunction with technical matters, structural features, achievement objects, and effects. In particular, the terminology used in the embodiments of the disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure.

With software-defined networking (SDN) and Network Function Virtualization (NFV), a cloud network architecture can effectively handle the diversified 5G services through various Key Performance Indicators (KPIs). Cloud Radio Access Networks (CRANs) with flexible base station functionality split options have been proposed to address the limitations of traditional network architectures.

The crac enables UEs to receive diverse services with energy-efficient, high spectral efficiency, or even lower network operating costs. However, CRANs face many technical challenges due to the large number of user connections required, the increasingly spectrum scarce and energy-limited devices. One potentially likely future possibility for solving these problems is non-orthogonal multiple access (NOMA). The orthogonal access schemes traditionally used in previous network standards may be very limited in the CRAN environment.

Maintaining orthogonal access to network resources can result in system connectivity, capacity limitations, and even increased latency due to signaling overhead. This limitation means that alternative multiple access schemes (multiple access schemes) need to be considered to meet the large-scale connection requirements of mtc in the 5G. In the description, several NOMA schemes have been proposed to address KPIs of the new air interfaces (NR) that cannot be addressed by orthogonal access. NOMA itself introduces multi-user interference because different data layers are multiplexed on the same orthogonal resource. Signals from different users may be distinguished according to user-specific signatures. The user described herein denotes a user equipment.

NOMA is particularly interesting for MTC because of the sporadic, delay tolerance and uplink biased traffic characteristics of the MTC devices. In designing an Uplink (UL) NOMA scheme, the following key aspects need to be considered:

unauthorized transmission;

support for overloaded transmission; and

low complexity receiver.

The present disclosure aims to optimize the combination of the CRAN and NOMA techniques to overcome the respective limitations. The main object of the present invention is to implement an unlicensed uplink power domain NOMA in CRAN. This is achieved by a novel open loop power control scheme and a fully optimized reception scheme.

Networks of 5G and beyond are expected to support a wide range of vertical services with different requirements. In fact, future networks need to provide access to various classes of services with heterogeneous traffic characteristics. Different service classes emphasize different KPIs. For MTC, the main KPIs include connection density, deep coverage, energy efficiency, etc.

With the advent of the Internet of things (IoT) application, it becomes critical to achieve simultaneous transmission of the large amount of data in wireless networks, which may need to deviate from the conventional orthogonal multiple access techniques such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), and Orthogonal Frequency Division Multiple Access (OFDMA). These orthogonal schemes require orthogonality of the signals of the devices in the time, frequency or code domain. Maintaining such orthogonality can be cumbersome, especially in high density scenarios, because of the large number of scheduling signals required. The base station needs to transmit a grant to each of a plurality of UEs as a scheduling signal in order to allocate radio resources to the UEs. Signals may also be separated in the spatial domain, using Multiple Input and Multiple Output (MIMO) and massive MIMO at the base station. The density of connected devices will necessarily increase, and it follows that it is crucial to adjust enough multiple access schemes to cope with the requirements of 5G and off-network MTC and internet of things applications.

One approach to circumvent the limitation is non-orthogonal multiple access schemes such as interleaved mesh-grid multiple access (IGMA) and Interleaved Division Multiple Access (IDMA).

These schemes allow a large number of devices to transmit simultaneously without orthogonal separation in the time, frequency or spatial domains. Device-specific signatures and sophisticated receivers such as Successive Interference Cancellation (SIC), Parallel Interference Cancellation (PIC), Message Passing Algorithm (MPA) and Maximum Likelihood (ML) are used to distinguish the different data streams. The 3GPP has studied the Uplink (UL) NOMA scheme in its 5G standardization work. Different NOMA schemes have been proposed, depending on various receiver and user specific signatures (signatures). For example, the main principle of power domain NOMA is to distinguish users in the power domain and employ SIC receivers. IGMA uses a combination of user-specific interleavers (interleavers) and sparse mapping patterns to distinguish signals. IGMA employs an Elementary Signal Estimator (ESE) or Maximum A Posteriori (MAP) algorithm on the receiving end. In addition to interleaver-based signatures, IDMAs employ ESE receivers. Other proposed programs include RSMA, MUSA, PDMA and NCMA, among others.

Although there are great possibilities in the future, these solutions have one major drawback, namely receiver complexity, especially in the densely connected framework. In addition, some of these schemes require closed-loop control. In the case of UL power domain NOMA, a power difference is required so that the SIC receiver can distinguish the different data signals. The power difference of the SIC's can be achieved by closed loop power control, which is not very practical in the dense scenario.

The invention solves the problem of power domain NOMA in CRAN. With macro-diversity of the CRAN, the disclosed method provides an efficient unlicensed uplink power domain NOMA scheme. To circumvent the need for closed loop control, the previously disclosed method uses macro-diversity of the CRAN to create the power difference required for efficient operation of NOMA. Macro diversity is the spatial and power domain diversity associated with user equipment in a macro cell.

Fifth generation (5G) wireless systems are typically cellular communication systems with a frequency range of 2(FR2), ranging from 24.25GHz to 52.6GHz, where multiplexed transmit (Tx) and receive (Rx) beams are used by a Base Station (BS) and/or User Equipment (UE) to cope with large path losses in the high frequency band. Due to hardware limitations and cost, the BS and the UE may be equipped with only a limited number of transmission and reception units (TXRUs).

Referring to fig. 1, a telecommunication system comprising a group 100a of a plurality of UEs, a Base Station (BS)200a and a network entity apparatus 300 performs the disclosed method according to an embodiment of the present disclosure. The plurality of UEs of the group 100a may include the UE 10a, the UE 10b, and other UEs. The representation of fig. 1 is for illustration only and not for limitation, and the system may comprise more user equipment, base stations and core network entities. Connections between devices and device components are shown as lines and arrows in the figure. The connection between the devices may be achieved by a wireless connection. Connections between equipment components may be made through cables, buses, wires, cables, or optical fibers. The UE 10a may include a processor 11a, a memory 12a, and a transceiver 13 a. The UE 10b may include a processor 11b, a memory 12b, and a transceiver 13 b. The base station 200a may include a baseband unit (BBU) 204 a. The baseband unit 204a may include a processor 201a, a memory 202a, and a transceiver 203 a. The network entity apparatus 300 may include a processor 301, a memory 302, and a transceiver 303. Each of the processors 11a, 11b, 201a, and 301 may be configured to implement the described functions, processes, and/or methods. The layers of the radio interface protocol may be implemented in said processors 11a, 11b, 201a and 301. Each of the

memories

12a, 12b, 202a and 302 operatively stores various programs and information to operate the connected processor. The

transceivers

13a, 13b, 203a and 303 are operatively coupled to a connected processor to transmit and/or receive radio signals or wired signals. The UE 10a may communicate with the UE 10b through a sidelink (sidelink). The base station 200a may be one of an eNB, a gNB, or other type of radio node.

Each of the processors 11a, 11b, 201a, and 301 may include a Central Processing Unit (CPU), an application-specific integrated circuit (ASIC), other chipsets, logic circuitry, and/or data processing devices. Each of the

memories

12a, 12b, 202a, and 302 may include a read-only memory (ROM), a Random Access Memory (RAM), a flash memory, a memory card, a storage medium, and/or other storage devices. Each of the

transceivers

13a, 13b, 203a, and 303 may include a baseband circuit and a Radio Frequency (RF) circuit to process RF signals. When the embodiments are implemented in software, the techniques described herein may be implemented with modules, units, programs, functions, entities, etc. that perform the functions described herein. Modules may be stored in memory and executed by the processor. The memories may be implemented within the processor or external to the processor, where these memories may be communicatively coupled to the processor via various means as is known in the art.

The network entity apparatus 300 may be a node in the CN. The CN may include an LTE CN or a 5G core (5G core, 5GC), which includes a user plane function (user plane function, UPF), a Session Management Function (SMF), a mobility management function (AMF), a Unified Data Management (UDM), a Policy Control Function (PCF), a Control Plane (CP)/User Plane (UP) split (CUPS), an authentication server (AUSF), an AUSF, a network slice selection function (network slice selection function, NSSF), and a Network Exposure Function (NEF).

Referring to fig. 2, a base station 200b is an embodiment of the base station 200a and includes a Central Controller (CC) 210, access points 211-1, 211-2. M is a positive integer. The central controller 210 may be implemented as a Central Unit (CU) and may include a BBU, such as BBU 204a, and the Access Points (APs) 211-1, 211-2. Each of the access points 211-1, 211-2,. and 211-M may be implemented to be integrated into a radio node, a Remote Unit (RU) or a Remote Radio Head (RRH), and may include a Transmission and Reception Point (TRP). Access points 211-1, 211-2,. and 211-M may be located at different locations.

The central controller 210 receives wireless signals from a group 100b of V User Equipments (UEs) through a group of M distributed radio nodes. V is a positive integer. The set of V user devices includes user devices 10-1, 10-2, 10-3, and. User devices 10-1, 10-2, 10-3, and 10-V may be located in different locations.

The technical problem considered belongs to the field of said high density connections and non-orthogonal multiple access (NOMA) in the CRAN system. For example, a CRAN network operating in Time Division Duplex (TDD) mode, where channel estimation is performed by uplink pilot transmission.

Each coherent slot (coherence slot) is divided between two uplink training instances, using orthogonal uplink preamble (pilot), uplink and downlink data transmission. One embodiment of the present disclosure handles the uplink from V UEs to M single-antenna Access Points (APs). In each slot, each AP independently performs uplink channel estimation.

The APs 211-1, 211-2,. and 211-M are distributed in the coverage area and managed by the central controller 210, which contains a centralized baseband unit (BBU) pool and handles physical layer and Medium Access Control (MAC) layer operations such as data decoding and encoding, scheduling, and power allocation. The APs are connected to the central controller 210 by a high performance transmission link called fronthaul (frontaul). The forwarding may be achieved through fiber optic cables or high bandwidth wireless channels. The system in fig. 2 comprises a simplified example where the base station 200b and the UE are CRANs. The APs 211-1, 211-2,. and 211-M perform channel estimation and the link-level transmission chain until equalization is achieved. The central controller 210 performs signal decoding, encoding, modulation, demodulation, scheduling, and MAC layer operations.

The invention mainly comprises two parts, namely open loop uplink power control based on power difference optimization and a novel receiver scheme.

Open loop uplink power control of NOMA in CRAN:

the steps of open loop uplink power control of the disclosed method are performed by the user equipment. Also, each user equipment 10-1, 10-2, 10-3, and.. 10-V in the user equipment group may perform open loop uplink power control of the disclosed method. The user equipment may include MTC equipment, but is not limited thereto. Each user equipment will adjust transmit power so that the user equipment compensates for the path loss to three APs under the optimal channel conditions. The resulting uplink transmission power may equally be derived at the central controller 210 from the uplink training signals of the user equipment 10-1, 10-2, 10-3 and.. 10-V.

Referring to fig. 3, the non-orthogonal multiple access method is performed by a user equipment, such as the user equipment 10a or the user equipment 10 b. The

user devices

10a and 10b are examples of the user devices 10-1, 10-2, 10-3, and 10.. 10-V. Also, each user equipment 10-1, 10-2, 10-3, and.. 10-V in the set of user equipment may perform the non-orthogonal multiple access method described in fig. 3.

The user equipment obtains power domain measurements from wireless signals of a set of distributed radio nodes (block 310). For example, the user equipment obtains a reference signal power value from a first radio node

Obtaining a reference signal power value from a second radio node

And obtaining a reference signal power value from the third radio node

Subscript u is as

And

represents that the user equipment is user equipment u.

Including the reference signal power value for a power domain measurement of a wireless signal from the distributed set of radio nodes

And

the reference signal power value represents the power of the reference signal from the radio node. In the group of APs 211-1, 211-2,. and 211-M, the first, second and third radio nodes are three radio nodes having stronger signal strength relative to the user equipment u. Although the user equipment u takes reference signal power values from three radio nodes in the example, the user equipment u may take reference signal power values from two, three or more radio nodes of the APs 211-1, 211-2,.. and 211-M.

The user equipment obtains a power domain characteristic value of the user equipment from the power domain measurement value (block 311). In an embodiment of the present disclosure, the power domain characteristic value of the user is represented as ρ for the user equipment u_uAnd is derived from the following equation:

wherein alpha is_uDenotes a priority-based coefficient, 0 ≦ α_u≤1；

Is a power offset for controlling how the uplink transmit power is used as the priority-based coefficient alpha_uVaries as a function of (a);

ρ_ULmaxrepresenting the maximum uplink power of the user equipment u. Thus, the power domain characteristic value of the user equipment is according to the userThe priority of the device.

In the embodiments of the present disclosure, the

Wherein

And alpha_uThe asterisk "in between is the multiplication operator. The user equipment transmits the power domain characteristic values for a multiple access procedure associated with the user equipment (block 312). In a disclosed embodiment, the user equipment transmits the power domain characteristic values to the APs 211-1, 211-2.

The first part of the invention focuses on the uplink power control, which is particularly important in power domain NOMA applications. The invention provides open loop uplink power control based on three-dimensional power domain triangulation. Although the user equipment takes reference signal power values from three radio nodes in the example, the user equipment may take the reference signal power values from two, four, or more of the AP radio nodes 211-1, 211-2,. and 211-M and obtain and transmit the power domain characteristic values from the reference signal power values.

Based on the resulting power, i.e. the power domain characteristic values of the user equipments 10-1, 10-2, 10-3 and.. 10-V, the central controller 210 derives detection weights to be used in the reception. The detection weights may be referred to as weighted channel gains. In addition to using Maximum Ratio Combining (MRC), the central controller 210 applies device-specific weighting vectors received at all APs to the radio signals of the user devices 10-1, 10-2, 10-3 and. These device-to-AP specific weights are applied to the received encoded data represented by the wireless signals of the user devices 10-1, 10-2, 10-3 and.. 10-V. For each user equipment, the weights are derived so as to maximize the power difference with respect to interference, thereby improving SINR at decoding even with minimal interference cancellation. In practice, for each device, the weights are used to determine the priority of the AP in order to improve the decoding conditions.

The proposed power control aims to ensure a power difference on the transmission side when necessary and to achieve an unlicensed access. Since the power domain multiple access described depends on power allocation, in some embodiments of the present disclosure, more power may be allocated to user equipments with high priority or low link reliability.

Each of the user equipments 10-1, 10-2, 10-3 and.. 10-V listens to the Reference Signals (RSs) of the three strongest APs and measures the RS power received from each AP, by

And

and (4) showing. The user equipment u obtains a routing vector

These measurements are shown. Then, the user equipment u calculates according to the formula (1)

As the modulus (module) of its measurement vector.

Uplink transmit power ρ of each of the user equipments 10-1, 10-2, 10-3 and 10_uCalculated in dBm according to said formula (2).

Where 0. ltoreq. alpha_u≦ 1 indicates a factor based on authenticity or based on priority. It can be set from 0.0 to 1.0 in steps of 0.1.

Is a power offset that controls how the uplink transmit power varies as a function of the priority/reliability coefficient. In a particular case, the function is defined as

Constant rho_ULmaxIs the maximum uplink power.

And alpha_uThe asterisks "in between are standard multiplication operators.

Such power control may ensure that user equipment in geographically close proximity uses transmit power that differs as a function only by its priority/reliability (P/R) factor. This means that closely located user equipments with similar priority/reliability indicators may use about the same uplink transmission power. This results in a fair allocation of throughput when using NOMA in the receiving end. On the other hand, if a user equipment featuring a higher priority or lower reliability is likely to use higher power, thereby increasing throughput when using NOMA for that particular user equipment. The proposed effect of the power control is shown in fig. 5.

The user equipment 10-1, 10-2, 10-3 and.. 10-V may employ a randomly generated power offset if the priority/reliability coefficient is not available. The user equipments 10-1, 10-2, 10-3 and 10-V produce power differences between the more closely located user equipments without a practical indicator (metric) to distinguish their traffic (traffic).

Receiver optimization for power domain NOMA in CRAN:

one embodiment of the described invention enables non-orthogonal access to a large number of MTC devices while using a reduced complexity receiver that exploits the inherent macro-diversity described in the CRAN. One of the main drawbacks of NOMA is the complexity of the receiver. SIC receivers are commonly used in the power domain NOMA. Such a receiver has another key disadvantage, namely error propagation.

One embodiment of the invention solves the problem by exploiting macro-diversity in the CRAN system to achieve simple linear detection and, where possible, reduce interference cancellation iterations.

Referring to fig. 4, a non-orthogonal multiple access method is performed in the central controller 210 of the base station 200 b. The central controller 210 receives wireless signals for a re-set of V user devices through the set of M distributed radio nodes (including APs 211-1, 211-2,. and 211-M) (block 410) the V user devices may include the user devices 10-1, 10-2, 10-3, and.. 10-V. the central controller 210 estimates the signal quality of each user device in the set of V user devices (block 411) and classifies the set of V user devices into a high signal quality sub-group and a low signal quality sub-group (block 412) based on the estimated signal quality of each user device in the set of V user devices The signal quality may include a signal to interference plus noise ratio (SINR), and the classifying is based on an SINR threshold. Alternatively, the signal quality may include one of a signal-to-noise ratio (SNR), a Reference Signal Received Power (RSRP), a Reference Signal Received Quality (RSRQ), a Radio Link Quality (RLQ), a Received Signal Strength Indication (RSSI), or a Channel Quality Indicator (CQI). In one embodiment, when one of the set of V user equipments is in the classification process, the central controller 210 classifies the user equipment in process as the high signal quality sub-group when the signal quality of the user equipment in process is greater than a signal quality threshold, and classifies the user equipment in process as the low signal quality sub-group when the signal quality of the user equipment is not greater than the signal quality threshold. Alternatively, when one of the set of V user equipments is in the classification process, the central controller 210 classifies the user equipment in process as the high signal quality sub-group when the signal quality of the user equipment in process is not less than the signal quality threshold, and classifies the user equipment in process as the low signal quality sub-group when the signal quality of the user equipment is less than the signal quality threshold.

The central controller 210 decodes wireless signals of user equipments belonging to the low signal quality sub-group using a multi-user interference cancellation scheme (block 413) and decodes wireless signals of user equipments belonging to the high signal quality sub-group without using the multi-user interference cancellation scheme (block 414). The multi-user interference cancellation scheme may include one of a Successive Interference Cancellation (SIC) or a Parallel Interference Cancellation (PIC) scheme.

The central controller 210 may obtain the detection weight of each user equipment in the group of V user equipments, and cluster the user equipments in the low signal quality sub-group into a cluster (cluster) according to the detection weight of each user equipment in the low signal quality sub-group. Clustering may be performed using k-means clustering. The central controller 210 may decode the radio signal belonging to a particular user equipment in the low signal quality sub-group by subtracting the radio signals of other one or more user equipments in the same cluster as the particular user equipment.

In one embodiment of the present invention, the central controller 210 further generates power differences between different user equipment signals at the receiving end through weighted coherent detection of the antennas of the plurality of APs. The weights associated with the user devices 10-1, 10-2, 10-3 and.. 10-V are generated from a graph-based optimization to increase the distance between the user devices 10-1, 10-2, 10-3 and.. 10-V in the power domain.

The central controller 210 can still use SIC as an uplink receiver, e.g., the transceiver 203a and the processor 201a in the BBU 204 a. In addition to performance improvement, the central controller 210 applies different detection weights to the user equipment for non-orthogonal multiple access to reduce SIC iteration. This is because the distance between the user equipments in the power domain is increased after applying the detection weight on the AP.

In some cases where many user devices are located in close proximity, the SIC is still needed. By utilizing the previously proposed uplink power control, the achievable rate for each user equipment using the SIC receiver is then dependent on the power offset of the user equipment, which is based on the priority or link reliability of the user equipment. Thus, the network can schedule user equipment in the power domain with enhanced fairness even with open loop power control and unlicensed access of the disclosed method.

As mentioned before, the user equipment v is associated with the weight vector y_v＝[γ_v1，…，γ_vM]In association with each other, the information is stored,

similarly, the user equipment u is associated with a weight vector γ_u＝[γ_u1，…，γ_uM]Associated, 0 ≦ γ _um1, the variable M is an index representing one AP in the set of APs 211-1, 211-2. M is more than or equal to 0 and less than or equal to M. The variables u and v are used as two user equipment indices. V is a variable representing the indices of the user equipments V in the set of V user equipments, said weight γ_vmRepresents an importance value of the APm with respect to the user equipment v in detecting a radio signal from the user equipment v. u is a variable representing the user equipment u index in the set of V user equipments, said weight γ_umRepresents an importance value of the radio node m with respect to the user equipment u when detecting a wireless signal from the user equipment u. The user equipment is different from said user equipment u.

The central controller 210 uses the weight vectors to detect wireless signals of the user devices 10-1, 10-2, 10-3, and. The weight vector is derived using a power domain optimization framework. The central controller 210 uses these weights at the receiver to increase the power difference between the radio signal and interference for each user equipment. These weights can be interpreted as projections in the power domain. Thus, the radio signal from each user equipment is detected in the power domain subspace, wherein said user equipment achieves an optimal power difference with other interfering user equipments.

Since the power domain NOMA depends on the differences of the user equipments in said power domain, the power difference between the user equipments will be maximized. Since the network, e.g. the base station 200b, does not interfere with the power control, increasing the power difference will be done in the central controller 210 at the receiving end by weighted coherent detection.

The power domain optimization includes a density minimization problem, which can be explained as follows:

wherein V is a variable representing the indices of the user equipments V in the group of V user equipments;

is an estimated channel coefficient between the user equipment u and the radio node m;

is an estimated channel coefficient between the user equipment v and the radio node m;

II | is Euclidean Norm;

θ_uis a signal quality threshold of the user equipment u;

ρ_ULmaxrepresents the maximum uplink power of the user equipment u;

for reference signal power value from first radio node

Reference signal power value from a second radio node

And a reference signal power value from the third radio node

α_uDenotes a priority-based coefficient, 0 ≦ α_uLess than or equal to 1; and

ρ_ULmaxrepresents a maximum uplink power of the user equipment v;

for a reference signal power value from the first radio node

A reference signal power value from the second radio node

And a reference signal power value from the third radio node

α_vDenotes a priority-based coefficient, 0 ≦ α_vLess than or equal to 1; and

is a power offset for controlling how the uplink transmit power is used as the priority-based coefficient alpha_vVaries as a function of (c).

The central controller 210 determines the detection weight of the user equipment u based on a density minimization problem.

At the receiving end, the central controller 210 uses the derived weights to characterize the importance of each AP in detecting wireless signals from user equipment. Uplink radio signals received by APm from the user equipment u

Given by:

wherein, g_umIs a channel coefficient between the user equipment u and the APm; n is a radical of_mIs the noise power; x is the number of_uIs a radio signal transmitted from the user equipment u; and V is the set of V user equipments. To detect the signal of user u, the central processing unit applies the optimized detection weights in addition to conjugate beam forming at each AP.

Although the proposed power control enables to distinguish between closely located user equipments based on their traffic priority or link reliability, low power domain distances between user equipments may still occur. This leads to the need to cancel interference. However, not all user equipments perform SIC, as the detection weights may contribute to the required power difference. Thus, SIC is only triggered on conditions related to the low power domain distance of the user equipment, which is characterized by a lower limit of the achievable average SINR.

Fig. 6 shows one embodiment of the disclosed NOMA methods. Referring to fig. 6, a plurality of user equipments modulate transmit power according to the disclosed triangulation power control (block 510). The central controller 210 derives a detection weight for each of the user devices 10-1, 10-2, 10-3 … and 10-V (block 511).

The central controller 210 estimates SINR of each user equipment after applying weighted Maximum Ratio Combining (MRC) and forms one set of user equipment delta called high signal quality sub-group and another set of user equipment called low signal quality sub-group

(block 512). For example, the central controller 210 calculates the weighted MRC (SINR)_v) And then the estimated SINR of the user equipment V E V is recorded as SINR_vIf SINR_v≧ θ, adding the user equipment v to the set Δ representing the high signal quality sub-group and if SINR_v<Theta then add user equipment v to the set representing said low signal quality subgroup

In (1). That is, a plurality of user equipments in the set Δ have SINR_v≧ θ, where θ is the SINR threshold required to correctly decode the signal. User equipment not verifying the SINR lower bound criterion is allocated to a set

The collection

Has SINR_v<θ。

The central controller 210 decodes the wireless signals of the plurality of user devices in the high signal quality subgroup without interference cancellation (block 513). When in useWhen decoding the signals of all user equipments in the high signal quality subgroup Δ, the central controller 210 takes a specific user equipment in the set Δ as the user equipment v, and obtains a decoded signal from a radio signal of the user equipment v according to the following formula

Wherein the detection weight γ_vmA value representing the importance of the radio node m in relation to the user equipment v in detecting wireless signals from the user equipment v; and

is an estimated channel coefficient between the user equipment and v said radio node m.

The central controller 210 iterates the steps by acquiring another user equipment v in the set delta as the user equipment.

The central controller 210 clusters the plurality of user equipments in the low signal quality sub-group into clusters according to the detection weights of the MTC devices (block 514). The central controller 210 assembles the set

As said user equipment v, according to said detection weight

Aggregating the set

And clustering said user equipments v and by aggregating said sets

As said user equipment v, to iterate said steps, thereby aggregating said set

Are clustered into L clusters. L is a positive integer. In this step, the K-means (K-mean) may be used for clustering.

The central controller 210 decodes the wireless signals of the plurality of user devices in the low signal quality sub-group using interference cancellation based on the cluster of detection weights (block 515). For the

The central controller 210 applies the SIC by subtracting the wireless signals of the user equipments in the same cluster before decoding the wireless signals of the user equipments. When detecting at the kth cluster C_kThe central controller 210 ranks the plurality of user equipments according to weights of the plurality of user equipments when the signal of the user equipment is received. At the k-th cluster C_kOf a plurality of user equipments arranged in (b), the radio signal in a given said user equipment v having a position in rank (i) by subtracting the radio signals of other user equipments

Decoding to generate a decoded signal for the user equipment v

Wherein Δ represents the high signal quality sub-group;

g_wmis a channel coefficient between a user equipment w and the radio node m;

w is a user equipment index indicating the set to which it belongs

User equipment w of (2); and

is a radio signal transmitted from the user equipment w.

Rank (i) refers to the rank of one user equipment among the ranked plurality of user equipments. The central controller 210 passes through the set

In the k-th cluster C_kAs the user equipment v, iterates the steps.

Fig. 7 shows the results of the numerical simulation, which shows the gain that the proposed invention can provide. The simulation compares the performance of a non-orthogonal multiple access receiver with a conventional SIC receiver and the disclosed power domain NOMA. The simulation utilizes a distributed antenna system comprising 40 single antenna access points, which serves 4 user equipments or Mobile Stations (MSs) sharing the same time-frequency resources. A plurality of APs and a plurality of user equipments are distributed within a circle having a radius of 100 m. The proposed uplink power control uses randomly generated power offsets

Fig. 7 shows the average bit error rate achievable by a plurality of user equipments as a function of their decoding rank, with a comparison of only two active user equipments. Significant improvements in the bit error rate can be obtained using the present disclosure. This gain comes from the optimized receiver, which takes advantage of the macro-diversity of the distributed antenna system. The proposed receiver applies AP and user specific weights to enhance the power difference between the interference and the wanted signal.

Fig. 8 shows a comparison of the average bit error rates achievable by a plurality of user equipments as a function of their decoding ranks when all user equipments are active. Also, significant improvements in the bit error rate can be achieved using the present disclosure. Although the overall error rate is deteriorated due to the increase in connection density, the invention can effectively cope with higher interference.

Fig. 9 is a block diagram of an example system 700 for wireless communication according to one embodiment of this disclosure. The embodiments described herein may be implemented into a system using any suitably configured hardware and/or software. Fig. 9 illustrates that the system 700 includes Radio Frequency (RF) circuitry 710, baseband circuitry 720, processing unit 730, memory/storage 740, display 750, camera 760, sensors 770, and input/output (input/output) interface 780, coupled to each other as shown. The processing unit 730 may include a circuit such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of general purpose processors and dedicated processors such as graphics processors and application processors. The processor may be coupled with the memory/storage and configured to execute instructions stored in the memory/storage to cause various applications and/or operating systems to run on the system.

The baseband circuitry 720 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may comprise a baseband processor. The baseband circuitry may handle various radio control functions enabling it to communicate with one or more radio networks through the radio frequency circuitry. The radio control functions may include, but are not limited to, signal modulation, encoding, decoding, radio frequency translation, and the like. In some embodiments, the baseband circuitry may provide communications compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry may support communication with 5G NR, LTE, Evolved Universal Terrestrial Radio Access Network (EUTRAN), and/or other Wireless Metropolitan Area Networks (WMANs), Wireless Local Area Networks (WLANs), Wireless Personal Area Networks (WPANs). Embodiments in which the baseband circuitry is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

In various embodiments, the baseband circuitry 720 may include circuitry to operate with signals that are not strictly considered to be baseband frequencies. For example, in some embodiments, the baseband circuitry may include circuitry to operate with signals having an intermediate frequency that is located between the baseband frequency and the radio frequency. The radio frequency circuit 710 may enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the radio frequency circuitry may include switches, filters, amplifiers, and the like to facilitate communication with a wireless network. In various embodiments, the radio frequency circuitry 710 may include circuitry for operating with signals that are not strictly considered to be at radio frequencies. For example, in some embodiments, the radio frequency circuitry may include circuitry to operate with signals having an intermediate frequency between a baseband frequency and a radio frequency.

In various embodiments, the transmitter circuitry, control circuitry, or receiver circuitry discussed above with respect to a User Equipment (UE), eNB, or gNB may be embodied in whole or in part in one or more of radio frequency circuitry, baseband circuitry, and/or processing units. As used herein, "circuitry" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC) that executes one or more software or firmware programs, an electronic Circuit, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group), a combinational logic Circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the electronics circuitry may be implemented in, or functions associated with, one or more software or firmware modules. In some embodiments, some or all of the components of the baseband circuitry, processing unit, and/or the memory/storage may be implemented together On a System On a Chip (SOC). The memory/storage 740 may be used to load and store data and/or instructions, for example, for a system. The memory/storage of one embodiment may comprise any combination of suitable volatile memory (e.g., Dynamic Random Access Memory (DRAM)) and/or non-volatile memory (e.g., flash memory).

In various embodiments, the I/O interface 780 may include one or more user interfaces designed to enable a user to interact with the system and/or peripheral component interfaces designed to enable peripheral components to interact with the system. The user interface may include, but is not limited to, a physical keyboard or keypad, a touchpad, a speaker, a microphone, and the like. The peripheral component interfaces may include, but are not limited to, a non-volatile memory port, a Universal Serial Bus (USB) port, an audio jack, and a power interface. In various embodiments, the sensor 770 may include one or more sensing devices to determine environmental conditions and/or location information associated with the system. In some embodiments, the sensors may include, but are not limited to, a gyroscope sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of or interact with baseband circuitry and/or RF circuitry to communicate with a positioning network, such as a Global Positioning System (GPS) satellite.

In various embodiments, the display 750 may include a display, such as a liquid crystal display and a touch screen display. In various embodiments, the system 700 may be a mobile computing device such as, but not limited to, a laptop computer device, a tablet computer device, a netbook, an ultrabook, a smartphone, and the like. In various embodiments, the system may have more or fewer components and/or different architectures. Where appropriate, the methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium, such as a non-transitory storage medium.

Embodiments of the present disclosure are a combination of techniques/procedures that may be employed in 3GPP specifications to create an end product.

Those of ordinary skill in the art will appreciate that each of the units, algorithms, and steps described and disclosed in the embodiments of the present disclosure is implemented using electronic hardware or a combination of software and electronic hardware. Whether these functions are run in hardware or software depends on the application conditions and design requirements of the solution. Those of ordinary skill in the art may implement the functionality of each particular application in different ways without departing from the scope of the present disclosure. As will be appreciated by those skilled in the art, since the operation procedures of the above-described systems, devices and units are substantially the same, reference may be made to the operation procedures of the systems, devices and units in the above-described embodiments. For ease of description and simplicity, these operations will not be described in detail.

It will be appreciated that the systems, devices and methods disclosed in the embodiments of the present invention may be implemented in other ways. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The division into the mentioned units is only based on the logic function, but other division methods are also possible when the division is implemented. It is possible that a plurality of units or elements are combined or integrated into another system. It is also possible that some features are omitted or skipped. On the other hand, the mutual coupling, direct coupling or communication coupling in the above description or discussion is realized by some ports, devices or units, and the coupling is realized by communication indirectly or by electronic, mechanical or other types of forms.

The elements referred to above as discrete elements for purposes of explanation may or may not be physically discrete elements. The units mentioned above may be physical units or not, that is, may be located in one place or distributed over a plurality of network units. Some or all of the units may be used according to the purpose of the embodiments. Furthermore, each functional unit in each embodiment may be integrated into one processing unit, or physically separated, or integrated into one processing unit having two or more units.

If implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on this understanding, the technical solutions proposed by the present disclosure are implemented essentially or partially in the form of software products. Alternatively, a part of the technical solution that is advantageous to the prior art may be implemented as a software product. A software product in a computer is stored in a storage medium and includes a plurality of instructions for execution by a computing device (e.g., a personal computer, a server, or a network device) to perform all or a portion of the steps disclosed in embodiments of the present disclosure. The storage medium includes a USB disk, a removable hard disk, a Read Only Memory (ROM), a Random Access Memory (RAM), a floppy disk, or other kind of medium capable of storing program code.

The disclosed NOMA approach mainly consists of two parts, open loop uplink power control based on power difference optimization and a new receiver scheme.

The invention solves the problem of power domain NOMA in CRAN. With macro-diversity of the CRAN, the disclosed method provides an efficient unlicensed uplink power domain NOMA scheme. To circumvent the need for closed loop control, the previously disclosed methods use macro-diversity of the CRANs to create the power difference required for efficient operation of NOMAs. Macro diversity is the spatial and power domain diversity associated with user equipment in a macro cell.

While the disclosure has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the disclosure is not limited to the disclosed embodiments, but is intended to cover various combinations made without departing from the broadest interpretation of the appended claims.

Claims

1. A non-orthogonal multiple access (NOMA) method, executable in a central controller of a base station, comprising:

receiving wireless signals of a set of V User Equipments (UEs) through a set of M distributed radio nodes, wherein V and M are positive integers;

2. The non-orthogonal multiple access method of claim 1, wherein the signal quality of a user device u in the set of V user devices is derived from a power domain eigenvalue of the user device u, and wherein the power domain eigenvalue is determined according to macro-diversity associated with the user device u.

3. The non-orthogonal multiple access method of claim 1, wherein the signal quality comprises a signal to interference-plus-noise ratio (SINR), and wherein the classification is based on an SINR threshold.

4. The non-orthogonal multiple access method of claim 1 wherein the multi-user interference cancellation scheme comprises Successive Interference Cancellation (SIC).

5. The non-orthogonal multiple access method of claim 1, wherein when one of the set of V user equipments is being processed in the classification, the method further comprises:

classifying the user equipment in the process into the high signal quality subgroup when the signal quality of the user equipment is not lower than a signal quality threshold; and

classifying the user equipment in the process into the low signal quality sub-group when the signal quality of the user equipment is below the signal quality threshold.

6. The non-orthogonal multiple access method of claim 1, further comprising:

acquiring the detection weight of each user equipment in the group of V user equipment; and

and clustering the user equipment in the low signal quality subgroup into a plurality of clusters (cluster) according to the detection weight of each user equipment in the low signal quality subgroup.

7. The non-orthogonal multiple access method of claim 6, wherein the clustering is clustering using k-means clustering.

8. The non-orthogonal multiple access method of claim 6, further comprising:

decoding a radio signal belonging to a particular user equipment in a cluster (cluster) of said low signal quality sub-groups by subtracting radio signals of other one or more user equipments in the same cluster (cluster) as said particular user equipment.

9. The non-orthogonal multiple access method of claim 8 wherein the detection weight of a user device u in the set of V user devices comprises a weight vector γ_u＝[γ_u1，...，γ_uM]，0≤γ_umM is a variable representing the index of one radio node in the set of M distributed radio nodes, 0M, u is a variable representing the index of one user device u in the set of V user devices, the weight γ_umRepresents an importance value of the radio node m with respect to the user equipment u when detecting a wireless signal from the user equipment u.

10. The non-orthogonal multiple access method of claim 9 wherein the detection weights for the user equipments u are determined based on a density minimization problem as follows:

is constrained to

And

| | | is euclidean Norm;

θ_uis a signal quality threshold of the user equipment u;

ρ_ULmaxrepresents the maximum uplink power of the user equipment u;

for reference signal power value from first radio node

Reference signal power value from a second radio node

And a reference signal power value from the third radio node

is a power offset for controlling how the uplink transmit power is used as the priority-based coefficient alpha_uVaries as a function of (b);

ρ_ULmaxrepresents a maximum uplink power of the user equipment v;

for a reference signal power value from the first radio node

A reference signal power value from the second radio node

And a reference signal power value from the third radio node

11. The non-orthogonal multiple access method of claim 10, wherein the wireless signal from the user equipment u signal received from radio node m is obtained by:

wherein, g_umIs a channel coefficient between the user equipment u and the radio node m;

N_mis the noise power;

x_uis a radio signal transmitted from the user equipment u; and

v is the set of V user devices.

12. The non-orthogonal multiple access method of claim 11, further comprising:

decoding a wireless signal belonging to a particular user equipment of the high signal quality subgroup to generate a decoded signal:

13. The non-orthogonal multiple access method of claim 12, further comprising:

decoding a kth cluster C among the plurality of clusters (cluster)_kWherein the kth cluster C_kThe plurality of user equipments in (b) are arranged according to the detection weights of the plurality of user equipments from the kth cluster C_kRadio signals of a given user equipment v of the arranged plurality of user equipments having rank v (i) by subtracting the other user equipments

To generate a decoded signal of said user equipment v

Wherein Δ represents the high signal quality sub-group;

g_wmis a channel coefficient between a user equipment w and the radio node m;

w is a user equipment index indicating the set to which it belongs

User equipment w of (2); and

is a radio signal transmitted from the user equipment w.

14. A non-orthogonal multiple access method, executable in a User Equipment (UE), comprising:

15. The non-orthogonal multiple access method of claim 14, further comprising:

obtaining a reference signal power value from a first radio node

Obtaining a reference signal power value from a second radio node

And obtaining a reference signal power value from the third radio node

Wherein, in the

And

subscript u in (a) denotes the user equipment as user equipment u;

wherein the power domain measurement value for power domain measurement of the wireless signal for the set of distributed radio nodes comprises the reference signal power value

And

16. the non-orthogonal multiple access method of claim 15, wherein the set of distributed radio nodes are three radio nodes having stronger signal strength relative to the user equipment u.

17. The non-orthogonal multiple access method of claim 15, wherein the power domain characteristic value of the user equipment is adjusted according to the priority of the user equipment.

18. The non-orthogonal multiple access method of claim 17, wherein the power domain characteristic value of the user is expressed as p for the user equipment_uAnd is obtained from the following equation:

and

wherein alpha is_uDenotes a priority-based coefficient, 0 ≦ α_u≤1；

Is a power offset for controlling how the uplink transmission power is, as said priority-based coefficient a_uVaries as a function of (a);

ρ_ULmaxrepresents the maximum uplink power of the user equipment u.

19. The non-orthogonal multiple access method of claim 18, wherein the non-orthogonal multiple access method is applied to a mobile station

Wherein

And alpha_uThe asterisk "", in between, is the multiplier.

20. A base station, comprising:

a transceiver; and

receiving, by a set of M distributed radio nodes, wireless signals from a set of V User Equipments (UEs), wherein V and M are positive integers;

decoding wireless signals of user equipments belonging to the low signal quality sub-group using a multi-user interference cancellation scheme; and

21. The base station of claim 20, wherein the signal quality of a user equipment u in the set of V user equipments is derived from a power domain eigenvalue of the user equipment u, and wherein the power domain eigenvalue is determined according to macro diversity associated with the user equipment u.

22. The base station of claim 20, wherein the signal quality comprises a signal to interference-plus-noise ratio (SINR), and wherein the classification is based on an SINR threshold.

23. The base station of claim 20, wherein the multi-user interference cancellation scheme comprises Successive Interference Cancellation (SIC).

24. The base station of claim 20, wherein when one of the set of V user equipments is being processed in the category, the processor further performs:

25. The base station of claim 20, wherein the processor further performs:

and clustering the user equipment in the low signal quality subgroup into a plurality of clusters according to the detection weight of each user equipment in the low signal quality subgroup.

26. The base station of claim 25, wherein the clustering is performed using k-means clustering.

27. The base station of claim 25, wherein the processor further performs:

28. The base station of claim 27, wherein the detection weight of a ue u in the set of V ues comprises a weight vector γ_u＝[γ_u1，...，γ_uM]，0≤γ_umM is a variable representing the index of one radio node in the set of M distributed radio nodes, 0M, u is a variable representing the index of one user device u in the set of V user devices, the weight γ_umRepresents a value of importance of the radio node m with respect to the user equipment u when detecting a radio signal from the user equipment u.

29. The base station of claim 28, wherein the detection weight of the user equipment u is determined based on a density minimization problem as follows:

is constrained to

And

| | | is euclidean Norm;

θ_uis a signal quality threshold of the user equipment u;

ρ_ULmaxrepresents the maximum uplink power of the user equipment u;

for reference signal power value from first radio node

Reference signal power value from a second radio node

And a reference signal power value from the third radio node

ρ_ULmaxrepresents a maximum uplink power of the user equipment v;

for a reference signal power value from the first radio node

A reference signal power value from the second radio node

And a reference signal power value from the third radio node

30. Base station according to claim 29, characterized in that the radio signal received from radio node m from the user equipment u signal is obtained by:

N_mis the noise power;

x_uis a radio signal transmitted from the user equipment u; and

v is the set of V user devices.

31. The base station of claim 30, wherein the processor further performs:

is the estimated channel coefficient between the user equipment and v said radio node m.

32. The base station of claim 31, wherein the processor further performs:

To generate a decoded signal of said user equipment v

Wherein Δ represents the high signal quality sub-group;

g_wmis a channel coefficient between a user equipment w and the radio node m;

w is a user equipment index indicating the set to which it belongs

User equipment w of (2); and

is a radio signal transmitted from the user equipment w.

33. A User Equipment (UE), comprising:

a transceiver; and

34. The user equipment of claim 33, wherein the processor further performs:

obtaining a reference signal power value from a first radio node

Obtaining a reference signal power value from a second radio node

And obtaining a reference signal power value from the third radio node

Wherein, in the

And

subscript u in (a) denotes the user equipment as user equipment u;

wherein the power domain measurement value that makes a power domain measurement of the wireless signal for the set of distributed radio nodes comprises the reference signal power value

And

35. the user equipment according to claim 34, characterized in that in the set of distributed radio nodes, the first radio node, the second radio node and the third radio node are three radio nodes having stronger signal strength with respect to the user equipment u.

36. The UE of claim 34, wherein the power domain characteristic value of the UE is adjusted according to a priority of the UE.

37. The user equipment as recited in claim 36, whereinCharacterized in that the power domain characteristic value of the user is expressed as p for the user equipment_uAnd is obtained from the following equation:

and

wherein alpha is_uDenotes a priority-based coefficient, 0 ≦ α_u≤1；

ρ_ULmaxrepresenting the maximum uplink power of the user equipment u.

38. The UE of claim 37, wherein the UE is configured to perform the operations of the UE and the UE

Wherein

And alpha_uThe asterisk "", in between, is the multiplier.

39. A chip, comprising:

a processor configured to invoke and execute a computer program stored in a memory to cause a device on which the chip is mounted to perform the method of any of claims 1 to 11.

40. A chip, comprising:

a processor configured to invoke and execute a computer program stored in memory to cause a device on which the chip is mounted to perform the method of any of claims 14 to 19.

41. A computer-readable storage medium storing a computer program, the computer program causing a computer to perform the method of any one of claims 1 to 13.

42. A computer-readable storage medium storing a computer program, the computer program causing a computer to perform the method of any one of claims 14 to 19.

43. A computer program product comprising a computer program, characterized in that the computer program causes a computer to perform the method of any of claims 1 to 13.

44. A computer program product comprising a computer program, characterized in that the computer program causes a computer to perform the method of any of claims 14 to 19.

45. A computer program for causing a computer to perform the method of any one of claims 1 to 13.

46. A computer program for causing a computer to perform the method of any one of claims 14 to 19.