CN106302299B

CN106302299B - Multi-user access method and device

Info

Publication number: CN106302299B
Application number: CN201510260128.6A
Authority: CN
Inventors: 戴建强; 袁志锋
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2015-05-20
Filing date: 2015-05-20
Publication date: 2020-06-05
Anticipated expiration: 2035-05-20
Also published as: CN106302299A; WO2016184241A1

Abstract

A multi-user access method and device; the method comprises the following steps: the method comprises the steps that a transmitter acquires rotation angle information of a channel between the transmitter and a receiver; the transmitter rotating the modulation symbols to be transmitted to the receiver on a mapped constellation according to the rotation angle information; and the transmitter forms a transmission signal by the rotated modulation symbol and transmits the transmission signal to the receiver. The invention can improve the efficiency of extracting or separating the information of each user from the aliasing signals.

Description

Multi-user access method and device

Technical Field

The present invention relates to the field of wireless communications, and in particular, to a multi-user access method and apparatus.

Background

The multi-user access system comprises an orthogonal access mode and a non-orthogonal access mode. In the orthogonal access mode, information of each user is transmitted on mutually orthogonal sub-channels, and the users do not interfere with each other, for example, traditional TDMA (time division multiple access), CDMA (code division multiple access) and OFDMA (orthogonal frequency division multiple access) belong to the category of orthogonal \ quasi-orthogonal access mode technology. The other, non-orthogonal access method, theoretically has better performance and higher capacity bound. The non-orthogonal access mode means that information of each user is transmitted on a 'whole channel', so that a system can more fully utilize time-frequency resources to achieve a higher capacity boundary, but simultaneously, when a receiver demodulates, the receiver faces information formed by mixing a plurality of user information together, the user information is mutually interfered, and therefore the receiver must extract or separate the information of each user from the mixed information.

A typical scenario of the non-orthogonal access method is a traditional multi-user uplink access scenario, where multiple access terminals or transmitters transmit respective information on the same time-frequency resource, and a receiver needs to separate or separate the information of each access user from an alias signal. Two terminals exchange data through a relay (or a base station), the terminals firstly send respective information to the relay on the same time-frequency resource, the relay firstly processes two routes of aliasing signals, usually, the bit XOR information of two user information is directly extracted from the two routes of aliasing signals, then the bit XOR information is broadcasted to the two terminals, after the two terminals receive the bit XOR information, the two terminals perform XOR once with the bit information which is sent out before, the bit information of the other terminal can be solved, thus completing information exchange once. It can be seen that the relay does not need to separately solve or separate the information of the two access terminals as in the conventional base station, but directly extracts the "bit xor" result of the information of the two access terminals from the alias signal.

In summary, regardless of the scenario, how the receiver overcomes the effect of the wireless channel and efficiently extracts or separates the information of each user from the aliasing information is a key issue.

Disclosure of Invention

The invention provides a scheme capable of improving the efficiency of extracting or separating the information of each user from aliasing signals, thereby improving the system performance of the two non-orthogonal access scenes.

In order to solve the problems, the following technical scheme is adopted:

a multi-user access method, comprising:

the method comprises the steps that a transmitter acquires rotation angle information of a channel between the transmitter and a receiver;

the transmitter rotating the modulation symbols to be transmitted to the receiver on a mapped constellation according to the rotation angle information;

and the transmitter forms a transmission signal by the rotated modulation symbol and transmits the transmission signal to the receiver.

Optionally, the obtaining, by the transmitter, the rotation angle information of the channel between the transmitter and the receiver includes any one of the following manners or any combination thereof:

obtained through feedback signaling of the receiver;

obtained by channel reciprocity.

Optionally, when the signal-to-noise ratio of the channel between the transmitter and the receiver is higher than or equal to a first threshold, the rotation angle represented by the rotation angle information is a rotation angle corresponding to a position at which the amplitude of the channel response obtained by the receiver according to channel estimation is minimum;

and when the signal-to-noise ratio of the channel between the transmitter and the receiver is lower than or equal to a first threshold value, the angle represented by the rotation angle information is the rotation angle corresponding to the position where the amplitude of the channel response obtained by the receiver according to the channel estimation is maximum.

Optionally, the angles represented by the rotation angle information include rotation angles of all points obtained by interpolation according to the rotation angles of two points; the two points are a first point and a second point obtained by the receiver according to channel estimation.

Optionally, the length of the rotation angle information is 2 to 5 bits, and is used for representing a rotation angle of 0 to 360 degrees, and/or representing a rotation angle of-360 to 0 degrees.

Optionally, the transmitter rotating the modulation symbols to be transmitted to the receiver on the mapped constellation according to the rotation angle information includes:

when the rotation angle theta represented by the rotation angle information is positive, the transmitter rotates the modulation symbol to be transmitted to the receiver by theta in a counterclockwise direction on the mapped constellation diagram; when the rotation angle theta represented by the rotation angle information is negative, the transmitter rotates the modulation symbol to be transmitted to the receiver by theta in a clockwise direction on the mapped constellation diagram;

alternatively, the first and second electrodes may be,

the transmitter rotates the modulation symbol to be transmitted to the receiver by theta in a clockwise direction on the mapped constellation diagram when the rotation angle theta indicated by the rotation angle information is positive, and rotates the modulation symbol to be transmitted to the receiver by theta in a counterclockwise direction on the mapped constellation diagram when the rotation angle theta indicated by the rotation angle information is negative.

Optionally, the acquiring, by the transmitter, the rotation angle information of the channel between the transmitter and the receiver includes:

the transmitter receiving downlink control information from the receiver; and acquiring the rotation angle information from the signaling transmitted by the downlink control information.

the transmitter transmits the information according to the rotation angleInformation the angle of rotation theta, multiplying the modulation symbols to be transmitted to the receiver by e^jθOr e^-jθ。

Optionally, the constellation map mapped by the modulation symbols includes a binary phase shift keying BPSK constellation, a quadrature phase shift keying QPSK constellation, a quadrature amplitude modulation QAM constellation, and a diamond constellation.

Optionally, the modulation symbols comprise data symbols and pilot symbols.

Optionally, the transmitter comprises a user equipment, UE; the receiver comprises a base station or a relay node.

A multi-user access method, comprising:

a receiver receives a multi-user aliasing signal; the aliased signals comprise transmit signals from at least two transmitters; the transmitting signal is formed by symbols obtained by rotating modulation symbols to be transmitted to the receiver on a mapped constellation diagram according to the rotation angle information of a channel between the transmitter and the receiver;

the receiver extracts or separates the transmitter information from the received multi-user aliased signal.

Optionally, before the receiver receives the multi-user alias signal, the method further includes:

and the receiver sends signaling to at least two transmitters, wherein the signaling comprises the rotation angle information.

Optionally, the sending, by the receiver, signaling to at least two transmitters includes:

and the receiver sends signaling to the at least two transmitters through downlink control information.

Optionally, before the receiver sends signaling to at least two transmitters, the method further includes:

and the receiver acquires the rotation angle information through channel estimation.

Optionally, the obtaining, by the receiver, the rotation angle information through channel estimation includes:

when the signal-to-noise ratio of a channel between the transmitter and the receiver is higher than or equal to a first threshold, the receiver takes a rotation angle corresponding to the position where the channel response amplitude obtained according to channel estimation is minimum as the rotation angle represented by the rotation angle information;

and when the signal-to-noise ratio of the channel between the transmitter and the receiver is lower than or equal to a first threshold, the receiver takes the rotation angle corresponding to the position with the maximum channel response amplitude obtained according to channel estimation as the rotation angle represented by the rotation angle information.

the receiver obtains rotation angles of a first point and a second point according to channel estimation, and obtains rotation angles of all points by interpolation according to the rotation angles of the first point and the second point; and taking the obtained rotation angles of all the points as the angles represented by the rotation angle information.

Alternatively, when the rotation angle obtained by the receiver according to the channel estimation is any one of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, or any one of 0, pi/2, pi, and 3 pi/2, the receiver uses 0 as the angle represented by the rotation angle information.

Optionally, the extracting or separating, by the receiver, information of each transmitter from the received multi-user alias signal includes:

the receiver demodulates the information of other transmitters with the interference of the first transmitter;

the receiver carries out serial interference elimination SIC to remove demodulated information; and demodulating the information of the first transmitter.

and the receiver solves the bit operation result of the information of the plurality of user equipment from the received multi-user aliasing signal.

Optionally, the bit operation includes a bit exclusive or operation, and the operation object is all bits of the information of the user equipment or a part of bits of the information of the user equipment.

A multi-user access apparatus, provided in a transmitter, comprising:

the acquisition module is used for acquiring the rotation angle information of a channel between the transmitter and the receiver;

a rotation module for rotating the modulation symbols to be transmitted to the receiver on a mapped constellation according to the rotation angle information;

and the sending module is used for forming a transmitting signal by the rotated modulation symbol and sending the transmitting signal to the receiver.

Optionally, the obtaining module obtains the rotation angle information of the channel between the transmitter and the receiver by any one or any combination of the following manners:

obtained through feedback signaling of the receiver;

obtained by channel reciprocity.

Optionally, the rotating module rotates the modulation symbols to be transmitted to the receiver on the mapped constellation diagram according to the rotation angle information by:

the rotation module rotates the modulation symbol to be sent to the receiver on the mapped constellation diagram according to the anticlockwise direction when the rotation angle theta represented by the rotation angle information is positive; when the rotation angle theta represented by the rotation angle information is negative, rotating the modulation symbol to be transmitted to the receiver by theta in a clockwise direction on a mapped constellation diagram;

alternatively, the first and second electrodes may be,

the rotation module rotates the modulation symbol to be transmitted to the receiver by theta in a clockwise direction on the mapped constellation diagram when the rotation angle theta represented by the rotation angle information is positive, and rotates the modulation symbol to be transmitted to the receiver by theta in a counterclockwise direction on the mapped constellation diagram when the rotation angle theta represented by the rotation angle information is negative.

Optionally, the obtaining, by the obtaining module, the rotation angle information of the channel between the transmitter and the receiver is:

the acquisition module receives downlink control information from the receiver; and acquiring the rotation angle information from the signaling transmitted by the downlink control information.

the rotation module multiplies modulation symbols to be transmitted to the receiver by e according to a rotation angle theta indicated by the rotation angle information^jθOr e^-jθ。

Optionally, the modulation symbols comprise data symbols and pilot symbols.

A multi-user access apparatus, provided in a receiver, comprising:

a receiving module for receiving a multi-user aliased signal; the aliased signals comprise transmit signals from at least two transmitters; the transmitting signal is formed by symbols obtained by rotating modulation symbols to be transmitted to the receiver on a mapped constellation diagram according to the rotation angle information of a channel between the transmitter and the receiver;

and the separation module is used for extracting or separating the information of each transmitter from the received multi-user aliasing signal.

Optionally, the apparatus further comprises:

a signaling sending module, configured to send signaling to at least two transmitters before the receiving module receives the multi-user alias signal, where the signaling includes the rotation angle information.

Optionally, the sending signaling of the signaling sending module to at least two transmitters means:

and the signaling sending module sends signaling to the at least two transmitters through downlink control information.

Optionally, the apparatus further comprises:

and the estimation module is used for acquiring the rotation angle information through channel estimation before the signaling sending module sends the signaling to at least two transmitters.

Optionally, the obtaining, by the estimation module, the rotation angle information through channel estimation includes:

when the signal-to-noise ratio of a channel between the transmitter and the receiver is higher than or equal to a first threshold value, the estimation module takes a rotation angle corresponding to the position with the minimum channel response amplitude obtained according to channel estimation as a rotation angle represented by the rotation angle information; and when the signal-to-noise ratio of the channel between the transmitter and the receiver is lower than or equal to a first threshold value, taking the rotation angle corresponding to the position with the maximum channel response amplitude obtained according to channel estimation as the rotation angle represented by the rotation angle information.

the estimation module obtains rotation angles of a first point and a second point according to channel estimation, and obtains rotation angles of all points by interpolation according to the rotation angles of the first point and the second point; and taking the obtained rotation angles of all the points as the angles represented by the rotation angle information.

Optionally, the estimation module takes 0 as the angle represented by the rotation angle information when the rotation angle obtained by the channel estimation is any one of 0 degree, 90 degrees, 180 degrees and 270 degrees, or any one of 0, pi/2, pi and 3 pi/2.

Optionally, the extracting or separating information of each transmitter from the received multi-user alias signal by the separation module is:

the separation module demodulates the information of other transmitters with the interference of the first transmitter; performing serial interference elimination SIC to remove demodulated information; and demodulating the information of the first transmitter.

the separation module resolves the result of bit operation of information of a plurality of user equipments from the received multi-user aliasing signal.

The invention provides a multi-user access scheme, after a transmitter acquires rotation angle information of a channel between the transmitter and a receiver, a constellation diagram mapped by modulation symbols to be sent to the receiver is rotated according to the rotation angle information, so that the received symbol mapping constellation diagram reaching the receiver is equivalent to the constellation diagram which is not rotated by the channel, namely the angle rotation caused by the channel is eliminated. And forming a transmission signal by the rotated symbol and transmitting the transmission signal to a receiver. For example, in a multi-user uplink access scene, the minimum Euclidean distance between adjacent quadrant constellation points can be amplified by eliminating the angular rotation brought by a channel, so that the performance of separating multi-user information by a user through SIC (successive interference cancellation) is improved. For example, in a bidirectional relay scenario, the angular rotation caused by the channel is eliminated, and the Euclidean distance between constellation points with different bit XOR results of the terminal information can be amplified, so that the bit XOR result of the terminal information can be efficiently extracted from the aliasing signal. In summary, the present invention has the advantage that information of each user can be efficiently extracted or separated from a multi-user aliased signal.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the example serve to explain the principles of the invention and not to limit the invention.

Fig. 1 is a flowchart of a multi-user access method according to a first embodiment of the present invention;

fig. 2 is a flowchart of a multi-user access method according to a second embodiment of the present invention;

fig. 3 is a schematic diagram of a multi-user access apparatus according to a third embodiment of the present invention;

fig. 4 is a schematic diagram of a multi-user access apparatus according to a fourth embodiment of the present invention;

fig. 5 is a schematic diagram of a multi-user uplink non-orthogonal access scenario in an implementation example one;

FIG. 6 is a flowchart illustrating a UE obtaining a transmission signal according to a conventional method in accordance with an embodiment;

FIG. 7 is a flowchart illustrating a UE obtaining a transmission signal according to an embodiment of the present invention in an embodiment I;

FIG. 8 is a diagram of a UE1 rotation symbol in an implementation example one;

FIG. 9(a) is a signal h of an edge UE1 arriving at a base station in the second embodiment₁A schematic diagram of S1 r;

FIG. 9(b) is a signal h of a central UE2 arriving at a base station in the second embodiment₂A schematic diagram of S2 r;

fig. 9(c) is a schematic diagram of a multi-user alias signal received by a base station when UE1 and UE2 transmit signals by using the rotation processing of the present embodiment in the second embodiment;

FIG. 10(a) is a signal h of an edge UE1 arriving at a base station in the second embodiment₁A schematic diagram of S1;

FIG. 10(b) shows a signal h of a central UE2 arriving at a base station in the second embodiment₂A schematic diagram of S2;

fig. 10(c) is a schematic diagram of a multi-user alias signal received by a base station when UE1 and UE2 transmit signals in a conventional manner in the second embodiment;

FIG. 11 is a simulation of the inventive arrangements in accordance with example two as compared to conventional arrangements;

fig. 12 is a schematic diagram of an implementation example three dual relay access scenario;

FIG. 13(a) is a signal h of an edge UE1 arriving at a base station in the third embodiment₁A schematic diagram of S1 r;

FIG. 13(b) is a signal h of a central UE2 arriving at a base station in the implementation example three₂A schematic diagram of S2 r;

fig. 13(c) is a schematic diagram of a multi-user alias signal received by a base station when the UE1 and UE2 transmit signals by using the rotation processing of the present embodiment in the third embodiment;

FIG. 14(a)) Is the signal h of the edge user equipment UE1 arriving at the base station in the implementation example three₁A schematic diagram of S1;

FIG. 14(b) is a signal h of a central UE2 arriving at a base station in the implementation example three₂A schematic diagram of S2;

fig. 14(c) is a schematic diagram of a multi-user alias signal received by a base station when UE1 and UE2 transmit signals in a conventional manner in the third embodiment;

FIG. 15 is a schematic diagram of a UE1 rotation symbol embodying example four;

FIG. 16(a) is a signal h of an edge user equipment UE1 arriving at a base station in the implementation example four₁A schematic diagram of S1 r;

FIG. 16(b) is a signal h of a central UE2 arriving at a base station in an example four implementation₂A schematic diagram of S2 r;

fig. 16(c) is a schematic diagram of a multi-user alias signal received by a base station when UE1 and UE2 transmit signals by using the rotation processing of the present embodiment in the fourth embodiment;

FIG. 17(a) is a signal h of an edge UE1 arriving at a base station in the example four implementation₁A schematic diagram of S1;

FIG. 17(b) is a signal h of a central UE2 arriving at a base station in an example four implementation₂A schematic diagram of S2;

fig. 17(c) is a schematic diagram of a multi-user alias signal received by a base station when UE1 and UE2 transmit signals in a conventional manner in the fourth embodiment.

Detailed Description

The technical solution of the present invention will be described in more detail with reference to the accompanying drawings and examples.

It should be noted that, if not conflicting, the embodiments of the present invention and the features of the embodiments may be combined with each other within the scope of protection of the present invention. Additionally, while a logical order is shown in the flow diagrams, in some cases, the steps shown or described may be performed in an order different than here.

An embodiment one, a multi-user access method, as shown in fig. 1, includes:

s101, a transmitter acquires rotation angle information of a channel between the transmitter and a receiver;

s102, the transmitter rotates the modulation symbols to be sent to the receiver on a mapped constellation diagram according to the rotation angle information;

s103, the transmitter forms a transmission signal by the rotated modulation symbol and sends the transmission signal to the receiver;

obtained through feedback signaling of the receiver;

obtained by channel reciprocity.

When the signal-to-noise ratio is exactly equal to the first threshold, whether the angle represented by the rotation angle information is the rotation angle corresponding to the position with the maximum channel response amplitude or the rotation angle corresponding to the position with the minimum channel response amplitude can be set by the user.

or

In a communication system, rotation is carried out according to the same rule (for example, the rotation is clockwise when theta is positive), and rotation angle information is determined (for example, theta is positive when the rotation angle brought by a channel is counterclockwise); the selected rule can achieve the following effects: the rotation performed by the transmitter is opposite to the channel rotation effect, so that after the transmitted signal reaches the receiver, the received signal cancels the channel rotation effect, the received symbol mapping constellation diagram reaching the receiver is equivalent to the constellation diagram which is not rotated by the channel, that is, the rotation performed by the transmitter can eliminate the angle rotation caused by the channel. That is, the transmitter rotates according to the rotation angle information and the rotation caused by the channel, and the directions are opposite and the same.

Optionally, the constellation mapped by the Modulation symbols includes BPSK (Binary Phase Shift Keying) constellation, QPSK (Quadrature Phase Shift Keying) constellation, QAM (Quadrature Amplitude Modulation) constellation, QAM constellation, and rhombus constellation.

the transmitter multiplies modulation symbols to be transmitted to the receiver by e according to the rotation angle theta indicated by the rotation angle information^jθOr e^-jθ。

The power of the rotated symbol is unchanged, and the size of the rotation angle is equal to the size of the phase change.

Optionally, the modulation symbols comprise data symbols and pilot symbols.

The second embodiment is a multi-user access method, as shown in fig. 2, including:

s201, a receiver receives a multi-user aliasing signal; the aliased signals comprise transmit signals from at least two transmitters; the transmitting signal is formed by symbols obtained by rotating modulation symbols to be transmitted to the receiver on a mapped constellation diagram according to the rotation angle information of a channel between the transmitter and the receiver;

s202, the receiver extracts or separates the information of each transmitter from the received multi-user aliasing signal.

Optionally, the receiver sends signaling to at least two transmitters:

Optionally, before the receiver obtains the rotation angle information through channel estimation, the method further includes: the receiver obtains CQI (channel quality indication) information of different user channels, including rotation angle information, and SNR information of the user channels, where SNRs of different user channels may be different or the same.

In a third embodiment, a multi-user access apparatus is disposed in a transmitter, as shown in fig. 3, and includes:

an obtaining module 31, configured to obtain rotation angle information of a channel between the transmitter and the receiver;

a rotation module 32 for rotating the modulation symbols to be transmitted to the receiver on the mapped constellation according to the rotation angle information;

and a sending module 33, configured to form a transmission signal from the rotated modulation symbol, and send the transmission signal to the receiver.

Optionally, the acquiring module 31 acquires the rotation angle information of the channel between the transmitter and the receiver by any one or any combination of the following manners:

obtained through feedback signaling of the receiver;

obtained by channel reciprocity.

Optionally, the rotation module 32 rotates the modulation symbols to be transmitted to the receiver on the mapped constellation according to the rotation angle information by:

the rotation module 32 rotates the modulation symbol to be transmitted to the receiver by θ in a counterclockwise direction on the mapped constellation diagram when the rotation angle θ represented by the rotation angle information is positive; when the rotation angle theta represented by the rotation angle information is negative, rotating the modulation symbol to be transmitted to the receiver by theta in a clockwise direction on a mapped constellation diagram;

alternatively, the first and second electrodes may be,

the rotation module 32 rotates the modulation symbol to be transmitted to the receiver by θ in a clockwise direction on the mapped constellation diagram when the rotation angle θ represented by the rotation angle information is positive, and rotates the modulation symbol to be transmitted to the receiver by θ in a counterclockwise direction on the mapped constellation diagram when the rotation angle θ represented by the rotation angle information is negative.

Optionally, the obtaining module 31 obtains the rotation angle information of the channel between the transmitter and the receiver by:

the acquiring module 31 receives downlink control information from the receiver; and acquiring the rotation angle information from the signaling transmitted by the downlink control information.

the rotation module 32 multiplies the modulation symbols to be transmitted to the receiver by e according to the rotation angle theta indicated by the rotation angle information^jθOr e^-jθ。

Optionally, the constellation mapped by the modulation symbols includes a BPSK constellation, a QPSK constellation, a QAM constellation, and a diamond constellation.

Optionally, the modulation symbols comprise data symbols and pilot symbols.

Optionally, the transmitter comprises a UE; the receiver comprises a base station or a relay node.

In a fourth embodiment, a multi-user access apparatus is disposed in a receiver, as shown in fig. 4, and includes:

a receiving module 41, configured to receive a multi-user alias signal; the aliased signals comprise transmit signals from at least two transmitters; the transmitting signal is formed by symbols obtained by rotating modulation symbols to be transmitted to the receiver on a mapped constellation diagram according to the rotation angle information of a channel between the transmitter and the receiver;

a separation module 42, configured to extract or separate information of each transmitter from the received multi-user alias signal.

Optionally, the apparatus further comprises:

Optionally, the extracting or separating module 42 extracts or separates information of each transmitter from the received multi-user alias signal by:

the separation module 42 demodulates the information of other transmitters with the interference of the first transmitter; performing serial interference elimination SIC to remove demodulated information; and demodulating the information of the first transmitter.

the separation module 42 solves the result of the bit operations of the information of the plurality of user equipments from the received multi-user aliased signal.

The above embodiments are further illustrated by the following examples.

Example of implementation

As shown in fig. 5, a multi-user uplink non-orthogonal access scenario is shown, where two user equipments UEs (UE1 and UE2) send information to a receiving Node (Node) on the same time-frequency resource, where the Node is a base station BS. The information sent by the two user equipments is mixed together in the radio resource and arrives at the base station, and the base station separates and demodulates the information of the two user equipments from the mixed signal. Hereinafter also referred to as UE1 as edge user equipment and UE2 as center user equipment.

And at the UE transmitting side, the UE modulates the bit information stream according to the channel condition between the UE and the BS and the coding modulation mode matched with the channel to obtain the modulation symbol of the information of the user equipment. Fig. 6 shows a conventional processing manner at the UE transmitting side (for example, the UE1 encodes the bit information stream I1 into C1 and modulates it into a modulation symbol S1, and the UE2 encodes the bit information stream I2 into C2 and modulates it into a modulation symbol S2), that is, after encoding and modulating the bit information stream, a transmission signal is formed (for example, the modulation symbol S1 forms a transmission signal T1, and the modulation symbol S2 forms a transmission signal T2).

Fig. 7 shows a processing method at the UE transmitting side according to the embodiment of the present invention, that is, after encoding and modulating a bit stream, a transmission signal is formed after a rotation process according to the obtained rotation angle information. For example, the modulation symbol S1 is rotated to obtain S1r, and S1r forms a transmission signal T1; the modulation symbol S2 is rotated to S2r, and S2r forms the transmission signal T1.

The UE acquires the rotation angle information, which means that the rotation angle information of a channel between the UE and a base station is acquired through signaling fed back by the base station in an FDD (frequency division duplex) system, that is, the base station feeds back signaling to two transmitters, the fed back signaling carries the rotation angle information, and the signaling can be sent through downlink control information. In a TDD (time division duplex) system, the rotation angle information can be obtained through channel reciprocity, and a base station is not required to feed back the signaling.

The rotation angle information can be obtained through channel estimation, when the overall SNR of the channel between the UE and the BS is higher than or equal to a first threshold value, the rotation angle information is the rotation angle corresponding to the position with the minimum amplitude in the channel response obtained according to the channel estimation, and when the overall SNR of the channel between the UE and the BS is lower than or equal to the first threshold value, the rotation angle information is the rotation angle corresponding to the position with the maximum amplitude in the channel response obtained according to the channel estimation.

The rotation angle information may also be obtained by interpolating between the rotation angle of the first point and the rotation angle of the second point. The SNR of the channel of the edge user device is different from the SNR of the channel of the center user device.

If the rotation angle is positive, the rotation is performed counterclockwise, and if the rotation angle is negative, the rotation is performed clockwise; the rotation angle information comprises 2bit, 3bit, 4bit and 5bit information quantized from 0 degree to 360 degrees and from-360 degrees to 0 degrees, and the performance can be ensured by quantizing the rotation angle to 3 bit. The rotation angle is θ.

The codeword bits C1, C2 are modulated into symbols S1, S2, and the constellation mapped by the modulation symbols includes QPSK (quadrature phase shift keying) constellation, QAM (quadrature amplitude modulation) constellation, diamond constellation, and other constellations. The modulation symbols include data symbols and pilot symbols.

The UE rotates the modulation symbols to be transmitted to the receiver on the mapped constellation according to the rotation angle information, and the resulting rotated symbols S1r, S2rThe power is unchanged, and the magnitude of the rotation angle is equal to the magnitude of the phase change. Rotating S1 by θ may be denoted as S1 × e^jθRotating S2 by θ may be denoted as S2 × e^jθ. The rotation is opposite to the channel rotation effect, so that after the transmitted signal reaches the receiver, the received signal cancels the rotation effect of the channel. Note that the channel rotation here does not take into account the effect of noise on the phase. When the rotation angle information is just 0 degree, + -90 degree, + -180 degree, + -270 degree, or rotates 0, + -pi/2, + -pi, + -3 pi/2, the equivalence is not rotating, and the rotation angle information sent by the base station is 0.

For example, the edge user equipments, the central user equipments all use QPSK modulation, the rotation angle of the channel of the edge user is θ, and the rotation angle of the channel of the central user equipment is 0. Fig. 8 shows that the edge user equipment rotates QPSK modulation symbols according to the rotation angle information. The rotation of the modulation symbols is opposite to the channel rotation effect, where the channel rotation effect is counterclockwise rotation of θ, and the edge user equipment rotates the QPSK modulation symbols clockwise by θ, where θ is a positive number.

And the UE forms a transmitting signal by the rotated modulation symbol and sends the transmitting signal to the base station.

Example II

After the UE performs the processing according to the method described in the first embodiment, the signal transmitted by the edge UE1 and the signal transmitted by the center UE2 are mixed together during the wireless channel transmission process, and the base station needs to separate the information of each UE from the multi-user mixed signal, where SIC separation is used. Assuming that the transmission process is affected by wireless channel fading and white gaussian noise, and UE1 and UE2 rotate according to the above embodiments and then transmit signals, the signals are superimposed when arriving at the base station as shown in fig. 9(a) to (c), where fig. 9(a) is signal h of edge user equipment UE1 arriving at the base station₁S1r, FIG. 9(b) is a signal h of a center UE2 arriving at the base station₂Schematic view of S2r, FIG. 9(c) is h₁S1r and h₂Schematic representation of S2r after superposition. The UE1, UE2 process the transmitted signals in a conventional manner, and the schematic diagrams of the signals being superimposed when arriving at the base station are shown in fig. 10(a) - (c), where fig. 10(a) is the arrival of the edge user equipment UE1 at the edge user equipment UE1Signal h of base station₁S1, FIG. 10(b) is a signal h of a center user equipment UE2 arriving at the base station₂Schematic view of S2, FIG. 10(c) is h₁S1 and h₂Schematic representation of S2 after superposition. Wherein h is₁Representing fading channel of edge user equipment, h₂Representing the fading channel of the center user. The part in the dashed circle indicates that one of the superimposed signal constellation points is affected by noise. When UE1 and UE2 transmit signals after rotating according to the above embodiments, the signals received by the base station are denoted as y-h₁·S1r+h₂S2r + n. n represents white gaussian noise.

As is easily seen from fig. 9, since the modulation symbols of the edge UE reaching the base station are previously rotated by the UE, the rotation effect of the channel is cancelled, and compared with the conventional method shown in fig. 10, the constellation coordinate axis is used as a boundary, and the superimposed signal is less likely to cross the boundary after being interfered by noise (for example, a part covered by a grid in the figure), so when the information of the UE1 is solved, the base station can directly demodulate the information of the UE1 with the interference of the information of the UE2, while the constellation shown in fig. 9 is more likely to correctly solve the information of the UE1 compared with the constellation shown in fig. 10; when the information of the UE2 is solved, the interference with the information of the UE2 directly demodulates the information of the UE1, then the SIC is performed to remove the information of the UE1, and finally the information of the UE2 is demodulated, so that the information of the UE2 is naturally easier to be solved correctly.

In other words, the embodiment of the present invention has the advantage that the information of each user equipment can be separated from the aliasing information more efficiently. As shown in fig. 11, when the difference between the power of the edge ue and the power of the center ue is 3dB, the performance of the edge ue according to this embodiment is 10 at the error block rate^-2The time gain reaches approximately 0.5 dB.

Example III

As shown in fig. 12, in a bidirectional Relay scenario, two

UEs

1 and 2 transmit information to a receiving Node on the same time-frequency resource, where the Node is a Relay Node Relay. The information of the two user equipment is mixed together in the wireless resource and reaches the Relay node, and then the Relay extracts the bit XOR result of the information of the two user equipment from the aliasing signal. Finally, Relay broadcasts this xor of the bits to both UEs.

After the transmitter processing procedure shown in fig. 7 in the first embodiment is implemented, the signal transmitted by UE1 and the signal transmitted by UE2 are mixed together during the wireless channel transmission process, and Relay needs to extract the "bit xor" result of the information of the two UEs from the aliasing information. Assuming that the transmission process is affected by wireless channel fading and white gaussian noise, and UE1 and UE2 rotate according to the above embodiments and then transmit signals, the signals are superimposed when arriving at Relay as shown in fig. 13(a) to (c), where fig. 13(a) is signal h of edge UE1 arriving at the base station₁S1r, FIG. 13(b) is a signal h of a center UE2 arriving at the base station₂Schematic view of S2r, FIG. 13(c) is h₁S1r and h₂Fig. 13 marks bit information mapped by different constellation points in a constellation diagram, and marks the result of "bit exclusive or" of information of two user equipments in partially aliased information, for example, the result of "bit exclusive or" of information of two user equipments in four constellation symbols in the middle of the constellation is S1 ⊕ S2 ═ 11. UE1 and UE2 process transmission signals in a conventional manner, and diagrams of signals being added together when reaching Relay are as shown in fig. 14(a) to (c), where fig. 14(a) is a signal h from an edge user equipment UE1 to a base station₁S1, FIG. 14(b) is a signal h of a center user equipment UE2 arriving at the base station₂Schematic view of S2, FIG. 14(c) is h₁S1 and h₂Schematic representation of S2 after superposition. Wherein h is₁Represents the fading channel, h, of the UE1₂Representing the fading channel of the UE 2.

When the UE1 and the UE2 transmit signals after rotating according to the above embodiments, the relay node receives the signals and indicates that y is h₁·S1r+h₂S2r + n, n is white Gaussian noise, the result of S1r ⊕ S2r is solved directly by y, and S1r or S2r does not need to be solved separately, as is easily seen from FIG. 13, the UE1 symbol reaching Relay is cancelled because the UE1 is rotated before, and the rotation effect of the channel is cancelled, compared with the traditional method shown in FIG. 14, the Euclidean distance between constellation points with different 'bit XOR' results of UE information can be made to be differentThe distance is amplified, the better the performance of demodulating the 'bit exclusive-or' result is, and thus the 'bit exclusive-or' result of two pieces of UE information can be efficiently extracted from the aliasing signal. After the bit XOR result of the UE information is taken out, the bit XOR result is broadcasted to the two UEs, and then the information of each user equipment can be solved. In other words, the embodiment of the present invention has the advantage that the information of each user equipment can be separated from the aliasing information more efficiently.

The bit calculation in this embodiment is a bit exclusive or calculation, all bits of the information of the user equipment are calculation targets, and the other bit calculations and the case where the calculation targets are partial bits of the information of the user equipment are not described.

Example four

Assume that the edge user equipment and the center user equipment all use BPSK modulation, the rotation angle of the channel of the edge user equipment is θ, and the rotation angle of the channel of the center user equipment is 0. Fig. 15 shows that the edge user equipment rotates the BPSK modulation symbols according to the rotation angle information. And the rotation of the modulation symbols is opposite to the rotation effect of the channel, wherein the channel rotation effect is that the BPSK modulation symbols are rotated by theta in a counterclockwise direction, the edge user equipment rotates the BPSK modulation symbols by theta + pi/2 in a clockwise direction, and the value of the theta is a positive number.

After the UE processes the signals according to the above method, the signals sent by the edge UE and the signals sent by the center UE are mixed together during the transmission of the radio channel. Assuming that the transmission process is affected by wireless channel fading and white gaussian noise, and UE1 and UE2 rotate according to the above embodiments and then transmit signals, the signals are superimposed when arriving at the base station as shown in fig. 16(a) to (c), where fig. 16(a) is the signal h of edge user equipment UE1 arriving at the base station₁S1r, FIG. 16(b) is a signal h of a center user equipment UE2 arriving at the base station₂Schematic view of S2r, FIG. 16(c) is h₁S1r and h₂The schematic diagram of the superimposed S2 r. The UE1 and UE2 process the transmitted signals in a conventional manner, and the signals are superimposed when reaching the base station as shown in fig. 17(a) - (c),wherein FIG. 17(a) is a signal h of an edge user equipment UE1 arriving at a base station₁S1, FIG. 17(b) is a signal h of a center user equipment UE2 arriving at the base station₂Schematic view of S2, FIG. 17(c) is h₁S1 and h₂Schematic representation of S2 after superposition. Wherein h is₁Representing fading channel of edge user equipment, h₂Representing the fading channel of the center user. The dashed circle portion indicates that one of the superimposed signal constellation points is affected by noise. When UE1 and UE2 transmit signals after rotating according to the above embodiments, the signals received by the base station are denoted as y-h₁·S1r+h₂S2r + n. n represents white Gaussian noise

As is easily seen from fig. 16, since the modulation symbols of the edge UEs reaching the base station are rotated by the UE before, the rotation effect of the channel is cancelled, and the modulation symbols are orthogonal to the modulation symbols of the center UEs reaching the base station, compared to the conventional method shown in fig. 17, the constellation coordinate axis is used as a boundary, and the superimposed signal is less likely to cross the boundary after being interfered by noise (for example, a portion covered by a grid in the figure), so when solving the information of the UE1, the base station can directly demodulate the information of the UE1 with the interference of the information of the UE2, while the constellation shown in fig. 16 is easier to correctly solve the information of the UE1 compared with the constellation shown in fig. 17; when the information of the UE2 is solved, the interference with the information of the UE2 directly demodulates the information of the UE1, then the SIC is performed to remove the information of the UE1, and finally the information of the UE2 is demodulated, so that the information of the UE2 is naturally easier to be solved correctly.

In other words, the embodiment of the present invention has the advantage that the information of each user equipment can be separated from the aliasing information more efficiently.

It will be understood by those skilled in the art that all or part of the steps of the above methods may be implemented by instructing the relevant hardware through a program, and the program may be stored in a computer readable storage medium, such as a read-only memory, a magnetic or optical disk, and the like. Alternatively, all or part of the steps of the above embodiments may be implemented using one or more integrated circuits. Accordingly, each module/unit in the above embodiments may be implemented in the form of hardware, and may also be implemented in the form of a software functional module. The present invention is not limited to any specific form of combination of hardware and software.

Although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A multi-user access method, comprising:

the transmitter rotating the modulation symbols to be transmitted to the receiver on a mapped constellation diagram according to the rotation angle information, wherein the direction of the rotation is opposite to the direction of the rotation angle information;

the transmitter forms a transmitting signal by the rotated modulation symbol and transmits the transmitting signal to the receiver;

when the signal-to-noise ratio of a channel between the transmitter and the receiver is higher than or equal to a first threshold, the rotation angle represented by the rotation angle information is a rotation angle corresponding to the position where the amplitude of the channel response obtained by the receiver according to channel estimation is minimum;

and when the signal-to-noise ratio of the channel between the transmitter and the receiver is lower than a first threshold value, the angle represented by the rotation angle information is the rotation angle corresponding to the position where the channel response amplitude obtained by the receiver according to channel estimation is maximum.

2. The method of claim 1, wherein the transmitter acquiring the rotation angle information of the channel with the receiver comprises any one of the following manners or any combination thereof:

obtained through feedback signaling of the receiver;

obtained by channel reciprocity.

3. The method of claim 1, wherein:

the angles represented by the rotation angle information comprise rotation angles of all points obtained by interpolation according to the rotation angles of the two points; the two points are a first point and a second point obtained by the receiver according to channel estimation.

4. The method of claim 1, wherein:

the length of the rotation angle information is 2-5 bits and is used for representing a rotation angle of 0-360 degrees and/or representing a rotation angle of-360-0 degrees.

5. The method of claim 4, wherein the transmitter rotating modulation symbols to be transmitted to the receiver on a mapped constellation according to rotation angle information comprises:

alternatively, the first and second electrodes may be,

6. The method of claim 1, wherein the transmitter acquiring rotation angle information of a channel with a receiver comprises:

7. The method of claim 1, wherein the transmitter rotating modulation symbols to be transmitted to the receiver on a mapped constellation according to rotation angle information comprises:

8. The method of claim 1, wherein the constellation map to which the modulation symbols are mapped comprises a Binary Phase Shift Keying (BPSK) constellation, a Quadrature Phase Shift Keying (QPSK) constellation, a Quadrature Amplitude Modulation (QAM) constellation, a diamond constellation.

9. The method of claim 1, wherein:

the modulation symbols include data symbols and pilot symbols.

10. The method of any one of claims 1 to 9, wherein:

the transmitter comprises User Equipment (UE); the receiver comprises a base station or a relay node.

11. A multi-user access method, comprising:

the receiver acquires rotation angle information through channel estimation;

the receiver sends signaling to at least two transmitters, wherein the signaling comprises the rotation angle information;

a receiver receives a multi-user aliasing signal; the aliased signals comprise transmit signals from at least two transmitters; the transmitting signal is formed by symbols obtained by rotating modulation symbols to be transmitted to the receiver on a mapped constellation diagram according to rotation angle information of a channel between the transmitter and the receiver, wherein the direction of rotation is opposite to the direction of the rotation angle information;

the receiver extracts or separates the information of each transmitter from the received multi-user aliasing signal;

the receiver acquiring the rotation angle information through channel estimation includes:

and when the signal-to-noise ratio of the channel between the transmitter and the receiver is lower than a first threshold value, the receiver takes the rotation angle corresponding to the position with the maximum channel response amplitude obtained according to channel estimation as the rotation angle represented by the rotation angle information.

12. The method of claim 11, wherein the receiver signaling to at least two transmitters comprises:

13. The method as claimed in claim 11, wherein said receiver acquiring said rotation angle information through channel estimation comprises:

14. The method of claim 13, wherein:

the receiver uses 0 as the angle represented by the rotation angle information when the rotation angle obtained by channel estimation is any one of 0 degree, 90 degrees, 180 degrees and 270 degrees or any one of 0, pi/2, pi and 3 pi/2.

15. The method of claim 11, wherein:

16. The method of claim 11, wherein the receiver extracting or separating transmitter information from the received multi-user aliased signal comprises:

17. The method of claim 11, wherein the receiver extracting or separating transmitter information from the received multi-user aliased signal comprises:

18. The method of claim 17, wherein:

the bit operation comprises a bit exclusive-or operation, and the operation object is all bits of the information of the user equipment or partial bits of the information of the user equipment.

19. The method of any one of claims 11 to 18, wherein:

20. A multi-user access apparatus disposed in a transmitter, comprising:

a rotation module, configured to rotate a modulation symbol to be transmitted to the receiver on a mapped constellation according to the rotation angle information, wherein a direction of the rotation is opposite to a direction of the rotation angle information;

the transmitting module is used for forming a transmitting signal by the rotated modulation symbol and transmitting the transmitting signal to the receiver;

21. The apparatus of claim 20, wherein the obtaining module obtains the rotation angle information of the channel between the transmitter and the receiver comprises any one of the following manners or any combination thereof:

obtained through feedback signaling of the receiver;

obtained by channel reciprocity.

22. The apparatus of claim 20, wherein:

23. The apparatus of claim 20, wherein:

24. The apparatus of claim 23, wherein the rotation module rotates the modulation symbols to be transmitted to the receiver on the mapped constellation based on the rotation angle information by:

alternatively, the first and second electrodes may be,

25. The apparatus as claimed in claim 20, wherein said obtaining module obtains the rotation angle information of the channel between the transmitter and the receiver by:

26. The apparatus of claim 20, wherein the rotation module rotates the modulation symbols to be transmitted to the receiver on the mapped constellation based on the rotation angle information by:

the rotation module transmits the modulation symbols to be transmitted to the receiver according to the rotation angle theta indicated by the rotation angle informationMultiplication by e^jθOr e^-jθ。

27. The apparatus of claim 20, wherein the constellation map of modulation symbol mappings comprises a Binary Phase Shift Keying (BPSK) constellation, a Quadrature Phase Shift Keying (QPSK) constellation, a Quadrature Amplitude Modulation (QAM) constellation, a diamond constellation.

28. The apparatus of claim 20, wherein:

the modulation symbols include data symbols and pilot symbols.

29. The apparatus of any one of claims 20 to 28, wherein:

30. A multi-user access apparatus disposed in a receiver, comprising:

the estimation module is used for acquiring the rotation angle information through channel estimation before the signaling sending module sends the signaling to the at least two transmitters;

a signaling sending module, configured to send a signaling to at least two transmitters before the receiving module receives the multi-user alias signal, where the signaling includes the rotation angle information;

a receiving module for receiving a multi-user aliased signal; the aliased signals comprise transmit signals from at least two transmitters; the transmitting signal is formed by symbols obtained by rotating modulation symbols to be transmitted to the receiver on a mapped constellation diagram according to rotation angle information of a channel between the transmitter and the receiver, wherein the direction of rotation is opposite to the direction of the rotation angle information;

a separation module, configured to extract or separate information of each transmitter from the received multi-user alias signal;

the estimation module acquires the rotation angle information through channel estimation, and the method comprises the following steps: when the signal-to-noise ratio of a channel between the transmitter and the receiver is higher than or equal to a first threshold value, the estimation module takes a rotation angle corresponding to the position with the minimum channel response amplitude obtained according to channel estimation as a rotation angle represented by the rotation angle information; and when the signal-to-noise ratio of the channel between the transmitter and the receiver is lower than a first threshold value, taking the rotation angle corresponding to the position with the maximum channel response amplitude obtained according to channel estimation as the rotation angle represented by the rotation angle information.

31. The apparatus of claim 30, wherein the signaling module sending signaling to at least two transmitters is configured to:

32. The apparatus of claim 30, wherein the estimation module obtains the rotation angle information through channel estimation by:

33. The apparatus of claim 30 or 32, wherein:

and when the rotation angle obtained by the estimation module according to the channel estimation is any one of 0 degree, 90 degrees, 180 degrees and 270 degrees or any one of 0, pi/2, pi and 3 pi/2, the estimation module takes 0 as the angle represented by the rotation angle information.

34. The apparatus of claim 30, wherein:

35. The apparatus of claim 30, wherein the means for extracting or separating the transmitter information from the received multi-user aliased signal comprises:

36. The apparatus of claim 30, wherein the means for extracting or separating the transmitter information from the received multi-user aliased signal comprises:

37. The apparatus of claim 36, wherein:

38. The apparatus of any one of claims 30 to 32 or 34 to 37, wherein: