CN106559363B

CN106559363B - Demodulation reference signal transmission method, channel estimation method and device

Info

Publication number: CN106559363B
Application number: CN201510624608.6A
Authority: CN
Inventors: 陈文洪; 陈润华; 高秋彬; 李辉; 拉盖施
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT; Datang Mobile Communications Equipment Co Ltd
Priority date: 2015-09-25
Filing date: 2015-09-25
Publication date: 2020-06-05
Anticipated expiration: 2035-09-25
Also published as: CN106559363A

Abstract

The embodiment of the invention discloses a demodulation reference signal transmission method, a channel estimation method and a channel estimation device based on a demodulation reference signal. In the method, a base station determines a DMRS port of user equipment; obtaining a DMRS sequence according to an orthogonal sequence corresponding to the DMRS port determined for the user equipment; and transmitting the corresponding DMRS sequence through the determined DMRS port for the user equipment. The user equipment acquires a DMRS port; determining a DMRS sequence corresponding to the DMRS port according to the acquired orthogonal sequence corresponding to the DMRS port; and estimating the downlink channel of the DMRS port according to the DMRS sequence. The embodiment of the invention can realize that the DMRS sequence is transmitted through the DMRS port.

Description

Demodulation reference signal transmission method, channel estimation method and device

Technical Field

The present invention relates to the field of wireless communication technologies, and in particular, to a demodulation reference signal transmission method, a channel estimation method based on a demodulation reference signal, and an apparatus thereof.

Background

In an LTE-a (Long Term Evolution-Advanced) system, a downlink DMRS (Demodulation Reference signal) may be transmitted from multiple ports, and a UE (user equipment) obtains channel estimation according to DMRS measurement, thereby performing data detection. Here, the DMRS may be referred to as DRS (Dedicated reference signal) or URS (UE-specific reference signal).

In the LTE system, a CDM (Code Division Multiplexing) transmission mode is generally adopted among multiple orthogonal DMRS ports, that is, the same physical resource is occupied but different orthogonal sequences are adopted. For example, port set {7,8,11,13} occupies the same set of physical resources for CDM transmission, and port set {9,10,12,14} occupies another set of the same physical resources for CDM transmission.

Currently, there is no clear scheme for how DMRS sequences are transmitted through DMRS ports.

Disclosure of Invention

The embodiment of the invention provides a demodulation reference signal transmission method, a channel estimation method and a channel estimation device based on a demodulation reference signal.

The demodulation reference signal transmission method provided by the embodiment of the invention comprises the following steps:

a base station determines a DMRS port of user equipment;

the base station obtains a DMRS sequence according to the orthogonal sequence corresponding to the DMRS port determined for the user equipment;

and the base station transmits the corresponding DMRS sequence through the DMRS port determined for the user equipment.

The channel estimation method based on the demodulation reference signal provided by the embodiment of the invention comprises the following steps:

the user equipment acquires a DMRS port;

the user equipment determines a DMRS sequence corresponding to the DMRS port according to the acquired orthogonal sequence corresponding to the DMRS port;

and the user equipment carries out downlink channel estimation of the DMRS port according to the DMRS sequence.

The base station provided by the embodiment of the invention comprises:

a determining module, configured to determine a DMRS port of a user equipment;

the acquisition module is used for obtaining a DMRS sequence according to the orthogonal sequence corresponding to the DMRS port determined for the user equipment;

and the transmitting module is used for transmitting the corresponding DMRS sequence through the DMRS port determined for the user equipment.

The embodiment of the invention provides user equipment, which comprises:

the acquisition module is used for acquiring the DMRS port;

the determining module is used for determining the DMRS sequence corresponding to the DMRS port according to the acquired orthogonal sequence corresponding to the DMRS port;

and the channel estimation module is used for estimating the downlink channel of the DMRS port according to the DMRS sequence.

In the embodiment of the invention, the base station generates the DMRS sequence according to the orthogonal sequence corresponding to the DMRS port configured for the user equipment and sends the DMRS sequence to the user equipment, and the user equipment determines the DMRS sequence corresponding to the DMRS port according to the orthogonal sequence corresponding to the DMRS port acquired from the base station and carries out downlink channel estimation of the DMRS port according to the DMRS sequence.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic diagram illustrating a transmission flow of a demodulation reference signal according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a channel estimation process based on a demodulation reference signal according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a base station according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a user equipment according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a base station according to another embodiment of the present invention;

fig. 6 is a schematic structural diagram of a user equipment according to another embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the LTE system, a CDM transmission scheme is generally used between multiple orthogonal DMRS ports, that is, the same physical resource is occupied but different orthogonal sequences are used. For example, a user equipment is allowed to perform 4-port MU-MIMO (Multi-user Multiple-Input Multiple-Output) transmission at most, and an OCC (Orthogonal) used for a DMRS port is usedThe systematic Code, orthogonal Convolutional Code) sequence is shown in table 1, wherein,

for the OCC sequence, DMRSs generated based on elements at the same position in the OCC sequence of each port occupy the same OFDM (Orthogonal Frequency Division Multiplexing) symbol.

TABLE 1

The base station in the embodiment of the present invention may be an evolved Node B (eNB or e-NodeB) in an LTE system, a macro base station, a micro base station (also referred to as a "small base station"), a pico base station, an Access Point (AP) or a Transmission Point (TP), and the like, which is not limited in this respect.

The user equipment in the embodiment of the present invention may be referred to as a Terminal (Terminal), a Mobile Station (MS), a Mobile Terminal (Mobile Terminal), an MTC Terminal, and the like, and may communicate with one or more core networks through a Radio Access Network (RAN).

For convenience of description, the following embodiments will be described taking a base station and a user equipment as examples.

The embodiment of the invention is suitable for multi-layer and multi-port downlink transmission, and particularly aims at MU-MIMO transmission.

The following describes a demodulation reference signal transmission scheme provided by an embodiment of the present invention.

Referring to fig. 1, a demodulation reference signal transmission method provided in an embodiment of the present invention includes the following specific steps:

step 101: the base station determines a DMRS port of the user equipment.

Specifically, the DMRS port is a DMRS port selected by the base station from a set of DMRS ports agreed with user equipment. Wherein the agreed port set may be a DMRS port set for MU-MIMO transmission.

One or more ports can be included in the DMRS port set, and a base station can allocate some or all of the ports in the port set to one user equipment. If the base station allocates part of the ports in the port set to one user equipment, in this case, the base station also configures other ports in the port set to other user equipments, and if the DMRS ports configured for a plurality of user equipments are from the same port set, the DMRS ports of the user equipments occupy the same physical resource.

In specific implementation, any one or more DMRS ports in the agreed port set may be configured for the user equipment, for example, the first M DMRS ports or the last M DMRS ports in the agreed port set are configured for the user equipment, where M is a positive integer. For example, if the port set is {7,8,11,13}, the user may allocate any one of the ports to user equipment a, and allocate the other ports in the set to user equipment B; any one of two groups of ports of {7,8} and {11,13} can be allocated to the user equipment A, and the other group of ports can be allocated to the user equipment B; of these, {7,8,11} or {7,8,11,13} may also be assigned to user equipment a.

Further, the base station also determines a DMRS scrambling sequence identifier corresponding to the DMRS port for the user equipment; the base station can generate the DMRS sequence according to the scrambling sequence corresponding to the DMRS scrambling sequence identification and the orthogonal sequence corresponding to the DMRS port of the user equipment.

In specific implementation, in this embodiment, the base station may configure the DMRS scrambling sequence identifier for the user equipment, or may not configure the DMRS scrambling sequence identifier, and if the base station does not configure the DMRS scrambling sequence identifier for the user equipment, the user equipment may use the DMRS scrambling sequence identifier that is fixedly configured. The user equipment can use the DMRS scrambling sequence and the orthogonal sequence corresponding to the configured DMRS port to generate the DMRS sequence corresponding to the DMRS port. The user equipment can also generate the DMRS sequence corresponding to the DMRS port by using the orthogonal sequence corresponding to the DMRS port configured for the user equipment.

In general, when performing Downlink transmission scheduling, a base station transmits a Downlink Control signaling, and the Downlink Control signaling is transmitted through a Physical Downlink Control Channel (PDCCH). The DCI (Downlink Control Information) of the PDCCH carries joint coding Information of the number of Downlink transmission layers configured for the user equipment and the port used for Downlink DMRS transmission. For example, assuming that the agreed port set includes DMRS ports {7,8,11,13}, the base station configures all ports in the port set for one user equipment, and allocates n_SCIDIf it is 0, it may be determined that the value of the corresponding joint code is 6 according to table 2, and the base station may send the joint code carried in DCI to the user equipment through the PDCCH, so that the user equipment knows the DMRS port allocated to the user equipment by the base station.

TABLE 2

In table 2 above, the number of transmission layers, port configuration and n_SCIDThe combination of the configurations can be represented by joint coding, for example, 3 bits are used to represent different transmission layer numbers, port configurations and n_SCIDThe combination of configurations. The "indication" in table 2 is the value after the joint coding; n is_SCIDIndicating the scrambling sequence number.

Table 2 is configured in advance on the base station side and the user equipment side. All the contents in table 2 may be configured, or only a part of the contents in table 2 may be configured.

It should be noted that table 2 is only one kind of transmission layer number, port configuration and n capable of supporting at most 4 orthogonal DMRS ports and realizing at most 4 layers MU-MIMO transmission_SCIDConfiguration example, the embodiments of the present invention do not exclude other transmission layer numbers, port configurations and n_SCIDThe situation of the configuration.

Step 102: and the base station obtains the DMRS sequence according to the orthogonal sequence corresponding to the DMRS port determined for the user equipment.

The base station may generate the DMRS sequence according to the orthogonal sequence corresponding to the DMRS port, or may generate the DMRS sequence in advance, and search for the corresponding DMRS sequence according to the orthogonal sequence corresponding to the DMRS port, which is not limited in the embodiment of the present invention.

Preferably, in some embodiments, after the orthogonal codes are accumulated and summed according to positions by the orthogonal sequences corresponding to part or all of the DMRS ports occupying the same physical resource in the DMRS port set, the absolute value of the accumulated sum of the orthogonal codes at each position is equal.

Specifically, the orthogonal sequence corresponding to the DMRS port determined for the user equipment and the orthogonal sequences corresponding to other parts or all of the DMRS ports occupying the same physical resource satisfy the following equation:

wherein K represents the number of ports in the agreed port set, W_i,jJ is more than or equal to 1 and less than or equal to K, and | represents absolute value operation, wherein j is used for identifying the position of the orthogonal code in the orthogonal sequence.

It can be seen that, because the orthogonal sequences corresponding to part of or all of the DMRS ports occupying the same physical resource accumulate and sum the orthogonal codes according to position, and the absolute value of the accumulated sum of the orthogonal codes at each position is equal, the DMRS signal powers on different symbols occupied by the DMRS are equal, and thus the problem of unbalanced transmission powers of different symbols is solved.

Preferably, each orthogonal code in the orthogonal sequence takes a value of 1 or-1.

In some embodiments, if the number of ports occupying the same physical resource in the DMRS port set is K, where K is greater than or equal to 4, orthogonal sequences corresponding to 4 ports of the K ports are respectively:

{ [ +1+1+1+1], [ +1-1+1-1], [ +1+1-1-1], [ -1+1+1-1] }, or,

{ [ +1+1+1+1], [ +1-1+1-1], [ -1-1+1+1], [ +1-1-1+1] }, or,

{ [ +1+1+1+1], [ -1+1-1+1], [ +1+1-1-1], [ +1-1-1+1] }, or,

{[-1-1-1-1],[+1-1+1-1],[+1+1-1-1],[+1-1-1+1]}。

in specific implementation, a DMRS port of a user equipment is selected by a base station for the user equipment from an agreed port set, where the port set may include a plurality of DMRS ports, and in the embodiment of the present invention, the port set includes 4 DMRS ports occupying the same physical resource, and orthogonal sequences corresponding to the 4 DMRS ports are as described above; in addition, the port set may also include 8 DMRS ports occupying the same physical resource, or other numbers of DMRS ports occupying the same physical resource are agreed, which is not limited in the present invention. The corresponding relation between the DMRS port and the orthogonal sequence is configured to the base station and the user equipment in advance, so that the base station and the user equipment determine the orthogonal sequence corresponding to the DMRS port of the user equipment according to the corresponding relation.

In other embodiments, taking 4 DMRS ports in the agreed port set as an example, the orthogonal sequence corresponding to each DMRS port may be any one of tables 3 to 6, or may be another orthogonal sequence satisfying the condition described in formula 1, and embodiments of the present invention are not listed any more. As an example, the 1 st port to the 4 th port in tables 3 to 6 may be: port 7, port 8, port 11, port 13.

The orthogonal codes in the orthogonal sequence may be OCC codes, and the following embodiments are all described with OCC codes. In an appointed port set, all orthogonal sequences corresponding to DMRS ports occupying the same physical resource occupy the same OFDM symbol based on DMRS generated by elements at the same position. In this embodiment, since the DMRS is transmitted on 4 OFDM symbols in one subframe, an OCC sequence corresponding to each port includes 4 OCC codes.

TABLE 3

TABLE 4

TABLE 5

TABLE 6

Taking table 3 as an example, in the 4 OCC sequences corresponding to the 1 st port to the 4 th port, the accumulated sum absolute value of the OCC codes in the first column is | -1+1+ 1| ═ 2, and similarly, the accumulated sum absolute value of the OCC codes in the second column, the third column, and the fourth column is equal to 2.

In other embodiments, the base station may further obtain the DMRS sequence according to the following method:

a base station determines a first orthogonal sequence corresponding to a DMRS port of user equipment; multiplying a first orthogonal sequence corresponding to N1 DMRS ports of the user equipment by-1 to obtain a second orthogonal sequence corresponding to N1 DMRS ports, wherein N1 is more than or equal to 1 and is more than or equal to N, and N is the number of the DMRS ports of the user equipment and is a positive integer; and the base station obtains the DMRS sequences of the DMRS ports of the user equipment according to the second orthogonal sequences corresponding to the N1 DMRS ports and the first orthogonal sequences corresponding to the N2 DMRS ports, wherein N2 is N-N1. The base station may determine the first orthogonal sequence corresponding to the DMRS port according to an existing communication protocol, for example, the existing communication protocol may be LTE Release 12.

By the method, the orthogonal sequence corresponding to the DMRS port determined for the user equipment and the orthogonal sequences corresponding to other parts or all DMRS ports occupying the same physical resource accumulate and sum the orthogonal codes according to the positions, and the absolute value of the accumulated sum of the orthogonal codes at each position is equal.

Taking the base station as an example to determine that the DMRS port of the user equipment is {7,8,11,13}, a first orthogonal sequence corresponding to the port {7,8,11,13} is: { [ +1+1+1+1], [ +1-1+1-1], [ +1+1-1-1], [ +1-1-1+1] }, the first orthogonal sequence [ +1-1-1+1] corresponding to the port {13} is multiplied by-1 to obtain a second orthogonal sequence [ -1+1+1-1], and then the base station obtains the DMRS sequence of the DMRS port of the user equipment according to the first orthogonal sequence corresponding to the port {7,8,11} and the second orthogonal sequence corresponding to the port {13}, that is { [ +1+1+1+1], [ +1-1], [ +1+1-1], [ -1+1+1-1] }; or multiplying-1 by a first orthogonal sequence [ +1+1-1-1] corresponding to the port {11} to obtain a second orthogonal sequence [ -1-1+1+1], and then the base station obtains the DMRS sequence of the DMRS port of the user equipment according to the first orthogonal sequence corresponding to the port {7,8,13} and the second orthogonal sequence corresponding to the port {11}, that is { [ +1+1+1+1], [ +1-1+1-1], [ -1-1+1], [ +1-1-1+1] }.

It can be seen that, after the orthogonal codes are accumulated and summed according to positions by the orthogonal sequences corresponding to part of or all of the DMRS ports occupying the same physical resource, the absolute value of the accumulated sum of the orthogonal codes at each position is equal, so that the DMRS signal powers on different symbols occupied by the DMRS are equal, and the problem of unbalanced transmission power of different symbols is solved.

In step 102, the DMRS sequence may be generated from the orthogonal sequence using the following formula:

wherein, w_p(l ') indicates the i ' th OCC code in the orthogonal sequence corresponding to the DMRS port, and l ' indicates the index value of the OFDM symbol occupied by the DMRS.

r represents a DMRS scrambling sequence and is calculated by the following formula:

wherein the content of the first and second substances,

c (i) represents a pseudo random sequence for the number of RBs (Resource Block ) with the largest downlink, and is initialized according to the following formula:

wherein n is_sRepresents a slot number;

a serving cell ID representing the UE; n is_SCIDAn ID indicating the scrambling sequence.

Step 103: and the base station transmits the corresponding DMRS sequence through the DMRS port determined for the user equipment.

In the demodulation reference signal transmission method provided in the above embodiment, the base station determines the DMRS port for the user equipment, obtains the DMRS sequence according to the orthogonal sequence corresponding to the DMRS port determined for the user equipment, and sends the corresponding DMRS sequence to the user equipment through the DMRS port determined for the user equipment.

According to the demodulation reference signal transmission method provided by the embodiment, the embodiment of the invention also provides a demodulation reference signal-based channel estimation method applied to the user equipment side.

Referring to fig. 2, a flowchart of a channel estimation method based on a demodulation reference signal according to an embodiment of the present invention is shown. The method comprises the following specific steps:

step 201: the user equipment acquires the DMRS port.

Specifically, the DMRS port is a DMRS port selected by the base station from a set of DMRS ports agreed with the user equipment. Wherein the agreed port set may be a DMRS port set for MU-MIMO transmission.

Further, the user equipment acquires a DMRS scrambling sequence identifier corresponding to the DMRS port; the user equipment can generate the DMRS sequence according to the scrambling sequence corresponding to the DMRS scrambling sequence identification and the orthogonal sequence corresponding to the DMRS port of the user equipment. In specific implementation, in this embodiment, the base station may configure the DMRS scrambling sequence identifier for the user equipment, or may not configure the DMRS scrambling sequence identifier, and if the base station does not configure the DMRS scrambling sequence identifier for the user equipment, the user equipment may use the DMRS scrambling sequence identifier that is fixedly configured. The user equipment can use the DMRS scrambling sequence and the orthogonal sequence corresponding to the configured DMRS port to generate the DMRS sequence corresponding to the DMRS port. The user equipment can also generate the DMRS sequence corresponding to the DMRS port by using the orthogonal sequence corresponding to the DMRS port configured for the user equipment.

Preferably, each OCC code in the orthogonal sequence has a value of 1 or-1.

In some embodiments, if the number of ports occupying the same physical resource in the DMRS port set is K, where K is greater than or equal to 4, orthogonal sequences corresponding to 4 ports of the K ports are respectively any one of tables 3 to 6, and may also be other orthogonal sequences satisfying the condition described in formula 1, which is not listed in this embodiment of the present invention.

Step 202: and the user equipment determines the DMRS sequence corresponding to the DMRS port according to the acquired orthogonal sequence corresponding to the DMRS port.

The user equipment may generate the DMRS sequence according to the orthogonal sequence corresponding to the DMRS port, or may generate the DMRS sequence in advance, and the user equipment may search for the corresponding DMRS sequence according to the orthogonal sequence corresponding to the DMRS port determined for the user equipment, which is not limited in this embodiment of the present invention.

The DMRS sequences corresponding to the DMRS ports may be calculated by formulas (2) to (4).

Optionally, in other embodiments, the user equipment may further determine the DMRS sequence corresponding to the DMRS port according to the following method:

the method comprises the steps that user equipment determines a first orthogonal sequence corresponding to a DMRS port of the user equipment; multiplying the first orthogonal sequences corresponding to N1 DMRS ports by-1 to obtain second orthogonal sequences corresponding to N1 DMRS ports, wherein N1 is larger than or equal to 1 and is larger than or equal to N, and N is the number of the DMRS ports of the user equipment and is a positive integer; and the user equipment obtains the DMRS sequences of the DMRS ports of the user equipment according to the second orthogonal sequences corresponding to the N1 DMRS ports and the first orthogonal sequences corresponding to the N2 DMRS ports, wherein N2 is N-N1. The first orthogonal sequence is an orthogonal sequence used in the prior art. The user equipment can determine a first orthogonal sequence corresponding to the DMRS port according to the existing communication protocol.

By the method, the orthogonal sequences corresponding to the DMRS ports of the user equipment and the orthogonal sequences corresponding to other parts or all DMRS ports occupying the same physical resource accumulate and sum the orthogonal codes according to the positions, and the absolute value of the accumulated sum of the orthogonal codes at each position is equal.

Taking the DMRS port of the user equipment as {7,8,11,13}, a first orthogonal sequence corresponding to the port {7,8,11,13} is: { [ +1+1+1+1], [ +1-1+1-1], [ +1+1-1-1], [ +1-1-1+1] }, the first orthogonal sequence [ +1-1-1+1] corresponding to the port {13} is multiplied by-1 to obtain a second orthogonal sequence [ -1+1+1-1], then the user equipment obtains a DMRS sequence of the DMRS port of the user equipment according to the first orthogonal sequence corresponding to the port {7,8,11} and the second orthogonal sequence corresponding to the port {13}, namely { [ +1+1+1+1], [ +1-1], [ +1+1-1], [ -1+1+1-1] }; or multiplying-1 by a first orthogonal sequence [ +1+1-1-1] corresponding to the port {11} to obtain a second orthogonal sequence [ -1-1+1+1], and then the user equipment obtains the DMRS sequence of the DMRS port of the user equipment according to the first orthogonal sequence corresponding to the port {7,8,13} and the second orthogonal sequence corresponding to the port {11}, that is { [ +1+1+1+1], [ +1-1+1], [ -1-1+1], [ +1-1-1+1] }.

Step 203: and the user equipment carries out downlink channel estimation of the DMRS port according to the DMRS sequence.

Preferably, when the user equipment performs downlink channel estimation, the user equipment may determine that the base station adopts the following DMRS port configuration scheme: configuring other DMRS ports except the DMRS port configured to the user equipment in the appointed port set to other user equipment, and performing downlink channel estimation according to the determined DMRS port configuration scheme; alternatively, it may also be determined that the base station employs the following DMRS port configuration scheme: and configuring other DMRS ports occupying the same physical resources with the DMRS ports of the user equipment to other user equipment, and performing downlink channel estimation according to the determined DMRS port configuration scheme.

Specifically, the user equipment may obtain a channel estimation value in each OFDM symbol in which the DMRS signal is located according to a DMRS sequence corresponding to a DMRS port configured to the user equipment and the received DMRS signal; and the user equipment superposes or averages the channel estimation values in all the OFDM symbols to obtain the channel estimation value corresponding to the DMRS port.

In this case, when the user equipment performs downlink channel estimation, the DMRS sequences on the respective OFDM symbols are generated according to all OCC codes in the orthogonal sequence corresponding to the DMRS port allocated to the user equipment, and downlink channel estimation is performed by combining the DMRS sequences on all the generated OFDM symbols with the DMRS received signal. That is, the user equipment performs estimation based on the DMRS sequences corresponding to the DMRS ports allocated to the user equipment in combination with the DMRS signals received on all symbols, instead of performing channel estimation on part of the OFDM symbols based on the DMRS signals received on part of the OFDM symbols, respectively. For example, the predetermined port set is {7,8,11,13}, the port configured for UE a is {7}, and the port configured for UE B is {11,13}, so that when UE a performs downlink channel estimation, the DMRS sequences on each OFDM symbol are generated according to all OCC codes in the OCC sequence corresponding to port 7, and the channel estimation values on each OFDM symbol are obtained based on the DMRS signals received on these OFDM symbols. The user equipment performs superposition or average processing on the channel estimation values on the OFDM symbols to obtain the final channel estimation value of the port 7. The processing method can eliminate or reduce the interference signals on other DMRS ports by utilizing the orthogonality among the orthogonal sequences, thereby ensuring the channel estimation accuracy on the DMRS ports allocated to the user equipment.

In the channel estimation based on the demodulation reference signal provided in the above embodiment, because the orthogonal sequences corresponding to the DMRS ports configured by the base station for the user equipment are orthogonal to each other, and the orthogonal sequences corresponding to part or all of the DMRS ports occupying the same physical resource accumulate and sum the orthogonal codes according to position, and the absolute value of the accumulated sum of the orthogonal codes at each position is equal, the DMRS signal powers on different symbols occupied by the DMRS are equal, and the problem of unbalanced transmission powers of different symbols is solved.

Based on the same technical concept, the embodiment of the invention also provides a base station, which is used for solving the problems that the DMRS signals on different symbols occupied by the DMRS have larger power difference and unbalanced transmission power.

Referring to fig. 3, a schematic structural diagram of a base station provided in an embodiment of the present invention is shown, where the base station includes:

a determining module 301, configured to determine a DMRS port of a user equipment;

an obtaining module 302, configured to obtain a DMRS sequence according to an orthogonal sequence corresponding to a DMRS port determined for the user equipment;

a sending module 303, configured to send the corresponding DMRS sequence through the DMRS port determined for the user equipment.

Further, the determining module 301 determines a DMRS scrambling sequence identifier corresponding to the DMRS port for the user equipment; the obtaining module 302 may generate a DMRS sequence according to a scrambling sequence corresponding to the DMRS scrambling sequence identifier and an orthogonal sequence corresponding to the DMRS port of the user equipment.

Specifically, the orthogonal sequence corresponding to the DMRS port determined by the determining module 301 for the user equipment and the orthogonal sequence corresponding to the other part or all of the DMRS ports occupying the same physical resource satisfy formula 1.

Because the orthogonal codes are accumulated and summed according to positions by the orthogonal sequences corresponding to part of or all of the DMRS ports occupying the same physical resource, and the absolute value of the accumulated sum of the orthogonal codes at each position is equal, the DMRS signal power on different symbols occupied by the DMRS is equal, and the problem of unbalanced transmission power of different symbols is solved.

Preferably, each OCC code in the orthogonal sequence has a value of 1 or-1.

The obtaining module 302 may generate the DMRS sequence according to the orthogonal sequence corresponding to the DMRS port, or may store the DMRS sequence in the base station in advance, and search for the corresponding DMRS sequence according to the orthogonal sequence corresponding to the DMRS port, which is not limited in this embodiment of the present invention.

Optionally, in some embodiments, the obtaining module 302 may further obtain the DMRS sequence according to the following method:

determining a first orthogonal sequence corresponding to a DMRS port of user equipment; multiplying a first orthogonal sequence corresponding to N1 DMRS ports of the user equipment by-1 to obtain a second orthogonal sequence corresponding to N1 DMRS ports, wherein N1 is more than or equal to 1 and is more than or equal to N, and N is the number of the DMRS ports of the user equipment and is a positive integer; and obtaining the DMRS sequences of the DMRS ports of the user equipment according to the second orthogonal sequences corresponding to the N1 DMRS ports and the first orthogonal sequences corresponding to the N2 DMRS ports, wherein N2 is N-N1. The base station can determine a first orthogonal sequence corresponding to the DMRS port according to the existing communication protocol.

The base station provided by the embodiment determines the DMRS port for the user equipment, obtains the DMRS sequence according to the orthogonal sequence corresponding to the DMRS port determined for the user equipment, and sends the corresponding DMRS sequence to the user equipment through the DMRS port determined for the user equipment.

Referring to fig. 4, a schematic structural diagram of a user equipment provided in an embodiment of the present invention is shown, where the user equipment includes:

an obtaining module 401, configured to obtain a DMRS port;

a determining module 402, configured to determine, according to the obtained orthogonal sequence corresponding to the DMRS port, a DMRS sequence corresponding to the DMRS port;

a channel estimation module 403, configured to perform downlink channel estimation on the DMRS port according to the DMRS sequence.

Further, the obtaining module 401 obtains a DMRS scrambling sequence identifier corresponding to a DMRS port of the user equipment; the determining module 402 may generate a DMRS sequence according to a scrambling sequence corresponding to the DMRS scrambling sequence identifier and an orthogonal sequence corresponding to a DMRS port of the user equipment.

Preferably, in some embodiments, after the orthogonal codes are accumulated and summed by the orthogonal sequences corresponding to part or all of the DMRS ports occupying the same physical resource in the DMRS port set of the user equipment by position, the absolute value of the accumulated sum of the orthogonal codes at each position is equal.

Preferably, each OCC code in the orthogonal sequence has a value of 1 or-1.

The determining module 402 may generate a DMRS sequence according to the orthogonal sequence corresponding to the DMRS port, or may generate a DMRS sequence in advance, and search for a corresponding DMRS sequence according to the orthogonal sequence corresponding to the DMRS port, which is not limited in the embodiment of the present invention.

Optionally, in some embodiments, the determining module 402 may further determine the DMRS sequence corresponding to the DMRS port according to the following method:

determining a first orthogonal sequence corresponding to the DMRS port; multiplying the first orthogonal sequences corresponding to N1 DMRS ports by-1 to obtain second orthogonal sequences corresponding to N1 DMRS ports, wherein N1 is larger than or equal to 1 and is larger than or equal to N, and N is the number of the DMRS ports of the user equipment and is a positive integer; and the user equipment obtains the DMRS sequences of the DMRS ports of the user equipment according to the second orthogonal sequences corresponding to the N1 DMRS ports and the first orthogonal sequences corresponding to the N2 DMRS ports, wherein N2 is N-N1. The user equipment can determine a first orthogonal sequence corresponding to the DMRS port according to the existing communication protocol.

Preferably, when the channel estimation module 403 performs downlink channel estimation according to the DMRS sequence corresponding to the DMRS port, it may be determined that the base station adopts the following DMRS port configuration scheme: configuring other DMRS ports except the DMRS port configured to the user equipment in the appointed port set to other user equipment, and performing downlink channel estimation according to the determined DMRS port configuration scheme; alternatively, it may also be determined that the base station employs the following DMRS port configuration scheme: and configuring other DMRS ports occupying the same physical resources with the DMRS ports of the user equipment to other user equipment, and performing downlink channel estimation according to the determined DMRS port configuration scheme.

Specifically, the channel estimation module 403 obtains a channel estimation value in each OFDM symbol in which the DMRS signal is located according to the DMRS sequence corresponding to the DMRS port configured to the user equipment and the received DMRS signal; and after the channel estimation values in all the OFDM symbols are superposed or averaged, obtaining the channel estimation value corresponding to the DMRS port.

In this case, when performing downlink channel estimation, the channel estimation module 403 generates DMRS sequences on each OFDM symbol according to all orthogonal codes in the orthogonal sequence corresponding to the DMRS port configured to the user equipment, and performs downlink channel estimation by combining the DMRS sequences on all generated OFDM symbols and the DMRS received signals. That is to say, the channel estimation module 403 needs to combine DMRS signals received on all symbols, and perform estimation based on the DMRS sequence corresponding to the DMRS port allocated to the user equipment, but cannot perform channel estimation on part of the OFDM symbols based on the DMRS signals received on part of the OFDM symbols.

The user equipment provided by the embodiment obtains the DMRS port determined by the base station, determines the corresponding orthogonal sequence according to the obtained DMRS port to obtain the DMRS sequence, and performs downlink channel estimation of the DMRS port according to the DMRS sequence.

Referring to fig. 5, a schematic structural diagram of a base station according to another embodiment of the present invention is provided, where the base station may include: a processor 501, a memory 502, a transceiver 503, and a bus interface.

The processor 501 is responsible for managing the bus architecture and general processing, and the memory 502 may store data used by the processor 501 in performing operations. The transceiver 503 is used to receive and transmit data under the control of the processor 501.

The bus architecture may include any number of interconnected buses and bridges, with one or more processors, represented by processor 501, and various circuits, represented by memory 502, being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 503 may be a number of elements, including a transmitter and a transceiver, providing a means for communicating with various other apparatus over a transmission medium.

The demodulation reference signal transmission flow disclosed in the embodiment of the present invention may be applied to the processor 501, or implemented by the processor 501. In implementation, the steps of the demodulation reference signal transmission flow may be implemented by hardware integrated logic circuits or instructions in software form in the processor 501. The processor 501 may be a general purpose processor, a signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, discrete gate or transistor logic, discrete hardware components, may implement or perform the methods, steps, and logic blocks disclosed in embodiments of the present invention. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 502, and the processor 501 reads the information in the memory 502 and completes the steps of the demodulation reference signal transmission process in combination with the hardware thereof.

Specifically, the processor 501, configured to read the program in the memory 502, executes the following processes:

determining a DMRS port of user equipment;

obtaining a DMRS sequence according to an orthogonal sequence corresponding to the DMRS port determined for the user equipment;

and transmitting the corresponding DMRS sequence through the determined DMRS port for the user equipment.

Specifically, the DMRS port is a DMRS port selected by the base station from a set of DMRS ports agreed with user equipment.

If the number of ports occupying the same physical resource in the DMRS port set is K, and K is greater than or equal to 4, the orthogonal sequences corresponding to 4 ports of the K ports are any one of tables 3 to 6, or may be other orthogonal sequences satisfying the condition described in formula 1, which is not listed any more in the embodiments of the present invention.

Optionally, the base station may further obtain the DMRS sequence according to the following method: determining a first orthogonal sequence corresponding to a DMRS port of the user equipment; multiplying a first orthogonal sequence corresponding to N1 DMRS ports of the user equipment by-1 to obtain a second orthogonal sequence corresponding to N1 DMRS ports, wherein N1 is greater than or equal to 1 and is greater than or equal to N, and N is the number of the DMRS ports of the user equipment and is a positive integer; and obtaining the DMRS sequences of the DMRS ports of the user equipment according to the second orthogonal sequences corresponding to the N1 DMRS ports and the first orthogonal sequences corresponding to the N2 DMRS ports, wherein N2 is N-N1. The base station can determine a first orthogonal sequence corresponding to the DMRS port according to the existing communication protocol.

Referring to fig. 6, a schematic structural diagram of a base station according to another embodiment of the present invention is provided, where the base station may include: a processor 601, a memory 602, a transceiver 603, and a bus interface.

The processor 601 is responsible for managing the bus architecture and general processing, and the memory 602 may store data used by the processor 601 in performing operations. The transceiver 603 is used for receiving and transmitting data under the control of the processor 601.

The bus architecture may include any number of interconnected buses and bridges, with one or more processors, represented by processor 601, and various circuits of memory, represented by memory 602, being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 603 may be a number of elements, including a transmitter and a transceiver, providing a means for communicating with various other apparatus over a transmission medium.

The channel estimation procedure disclosed in the embodiment of the present invention may be applied to the processor 601, or implemented by the processor 601. In implementation, the steps of the channel estimation procedure may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 601. The processor 601 may be a general purpose processor, a signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, discrete gate or transistor logic, discrete hardware components, may implement or perform the methods, steps, and logic blocks disclosed in embodiments of the present invention. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 602, and the processor 601 reads the information in the memory 602 and completes the steps of the channel estimation procedure in conjunction with its hardware.

Specifically, the processor 601, configured to read the program in the memory 602, executes the following processes:

acquiring a DMRS port;

determining a DMRS sequence corresponding to the DMRS port according to the acquired orthogonal sequence corresponding to the DMRS port;

and estimating the downlink channel of the DMRS port according to the DMRS sequence.

Specifically, the DMRS port is a DMRS port selected by the base station from a set of DMRS ports agreed with the user equipment.

Further, the user equipment acquires a DMRS scrambling sequence identifier corresponding to the DMRS port; the user equipment can generate the DMRS sequence according to the scrambling sequence corresponding to the DMRS scrambling sequence identification and the orthogonal sequence corresponding to the DMRS port of the user equipment.

Preferably, after the orthogonal codes are accumulated and summed by the orthogonal sequences corresponding to part or all of the DMRS ports occupying the same physical resource in the DMRS port set according to position, the absolute value of the accumulated sum of the orthogonal codes at each position is equal.

Optionally, the user equipment may further determine the DMRS sequence corresponding to the DMRS port according to the following method: the processor 601 determines a first orthogonal sequence corresponding to the DMRS port; multiplying the first orthogonal sequences corresponding to N1 DMRS ports by-1 to obtain second orthogonal sequences corresponding to N1 DMRS ports, wherein N1 is larger than or equal to 1 and is larger than or equal to N, and N is the number of the DMRS ports of the user equipment and is a positive integer; and the user equipment obtains the DMRS sequences of the DMRS ports of the user equipment according to the second orthogonal sequences corresponding to the N1 DMRS ports and the first orthogonal sequences corresponding to the N2 DMRS ports, wherein N2 is N-N1. The user equipment can determine a first orthogonal sequence corresponding to the DMRS port according to the existing communication protocol.

Preferably, when performing downlink channel estimation according to the DMRS sequence corresponding to the DMRS port, the processor 601 may determine that the base station employs the following DMRS port configuration scheme: configuring other DMRS ports except the DMRS port configured to the user equipment in the appointed port set to other user equipment, and performing downlink channel estimation according to the determined DMRS port configuration scheme; alternatively, it may also be determined that the base station employs the following DMRS port configuration scheme: and configuring other DMRS ports occupying the same physical resources with the DMRS ports of the user equipment to other user equipment, and performing downlink channel estimation according to the determined DMRS port configuration scheme.

Preferably, the processor 601 obtains a channel estimation value in each OFDM symbol where the DMRS signal is located according to the DMRS sequence corresponding to the DMRS port configured to the user equipment and the received DMRS signal; and the user equipment superposes or averages the channel estimation values in all the OFDM symbols to obtain the channel estimation value corresponding to the DMRS port.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A demodulation reference signal transmission method, comprising:

a base station determines a demodulation reference signal (DMRS) port of user equipment;

the base station transmits a corresponding DMRS sequence through the DMRS port determined for the user equipment;

the base station obtains the DMRS sequence according to the orthogonal sequence corresponding to the DMRS port determined for the user equipment, and the method comprises the following steps:

the base station determines a first orthogonal sequence corresponding to a DMRS port of the user equipment;

the base station multiplies-1 by the first orthogonal sequences corresponding to N1 DMRS ports of the user equipment to obtain second orthogonal sequences corresponding to N1 DMRS ports, wherein N1 is larger than or equal to 1 and is larger than or equal to N, and N is the number of the DMRS ports of the user equipment and is a positive integer;

and the base station obtains the DMRS sequences of the DMRS ports of the user equipment according to the second orthogonal sequences corresponding to the N1 DMRS ports and the first orthogonal sequences corresponding to the N2 DMRS ports, wherein N2 is N-N1.

2. The method of claim 1, wherein the DMRS port is a DMRS port selected by the base station from a set of DMRS ports agreed with a user equipment.

3. The method of claim 2, wherein after orthogonal sequences corresponding to part or all of the DMRS ports occupying the same physical resources in the set of DMRS ports accumulate and sum orthogonal codes by position, the absolute value of the accumulated sum of the orthogonal codes at each position is equal.

4. The method of claim 3, wherein each orthogonal code in the orthogonal sequence has a value of 1 or-1.

5. The method of claim 3, wherein if the number of ports occupying the same physical resource in the DMRS port set is K, where K is greater than or equal to 4, then the orthogonal sequences corresponding to 4 ports of the K ports are respectively:

{ [ +1+1+1+1], [ +1-1+1-1], [ +1+1-1-1], [ -1+1+1-1] }, or,

{ [ +1+1+1+1], [ +1-1+1-1], [ -1-1+1+1], [ +1-1-1+1] }, or,

{ [ +1+1+1+1], [ -1+1-1+1], [ +1+1-1-1], [ +1-1-1+1] }, or,

{[-1-1-1-1],[+1-1+1-1],[+1+1-1-1],[+1-1-1+1]}。

6. the method of any of claims 1 to 5, further comprising: the base station determines a DMRS scrambling sequence identifier corresponding to the DMRS port for the user equipment;

and the DMRS sequence is generated according to the scrambling sequence corresponding to the DMRS scrambling sequence identification and the orthogonal sequence corresponding to the DMRS port of the user equipment.

7. A channel estimation method based on demodulation reference signals, comprising:

the method comprises the steps that user equipment obtains a demodulation reference signal DMRS port;

the user equipment carries out downlink channel estimation of the DMRS port according to the DMRS sequence;

the user equipment determines the DMRS sequence corresponding to the DMRS port according to the acquired orthogonal sequence corresponding to the DMRS port, and the method comprises the following steps:

the user equipment determines a first orthogonal sequence corresponding to the DMRS port;

the user equipment multiplies-1 by the first orthogonal sequences corresponding to N1 DMRS ports to obtain second orthogonal sequences corresponding to N1 DMRS ports, wherein N1 is larger than or equal to 1 and is larger than or equal to N, and N is the number of the DMRS ports of the user equipment and is a positive integer;

and the user equipment obtains the DMRS sequences of the DMRS ports of the user equipment according to the second orthogonal sequences corresponding to the N1 DMRS ports and the first orthogonal sequences corresponding to the N2 DMRS ports, wherein N2 is N-N1.

8. The method of claim 7, wherein the DMRS port is a DMRS port selected by a base station from a set of DMRS ports agreed with a user equipment.

9. The method of claim 8, wherein after orthogonal sequences corresponding to some or all of the DMRS ports occupying the same physical resources in the set of DMRS ports accumulate and sum orthogonal codes by position, the absolute value of the accumulated sum of the orthogonal codes at each position is equal.

10. The method of claim 9, wherein each orthogonal code in the orthogonal sequence has a value of 1 or-1.

11. The method of claim 9, wherein if the number of ports occupying the same physical resource in the DMRS port set is K, where K is greater than or equal to 4, then orthogonal sequences corresponding to 4 ports of the K ports are respectively:

{ [ +1+1+1+1], [ +1-1+1-1], [ +1+1-1-1], [ -1+1+1-1] }, or,

{ [ +1+1+1+1], [ +1-1+1-1], [ -1-1+1+1], [ +1-1-1+1] }, or,

{ [ +1+1+1+1], [ -1+1-1+1], [ +1+1-1-1], [ +1-1-1+1] }, or,

{[-1-1-1-1],[+1-1+1-1],[+1+1-1-1],[+1-1-1+1]}。

12. the method of any of claims 7 to 11, further comprising: acquiring a DMRS scrambling sequence identifier corresponding to the DMRS port;

13. The method according to any of claims 7 to 11, wherein the ue performs downlink channel estimation, comprising:

the user equipment determines that the base station adopts the following DMRS port configuration scheme: configuring other DMRS ports except the DMRS port configured to the user equipment in the appointed port set to other user equipment, and performing downlink channel estimation according to the determined DMRS port configuration scheme; or

The user equipment determines that the base station adopts the following DMRS port configuration scheme: and configuring other DMRS ports occupying the same physical resources with the DMRS ports of the user equipment to other user equipment, and performing downlink channel estimation according to the determined DMRS port configuration scheme.

14. The method of claim 13, wherein the ue performs downlink channel estimation, comprising:

the user equipment obtains a channel estimation value in each orthogonal frequency division multiplexing OFDM symbol in which the DMRS signal is located according to the DMRS sequence corresponding to the DMRS port configured to the user equipment and the received DMRS signal;

and the user equipment superposes or averages the channel estimation values in all the OFDM symbols to obtain the channel estimation value corresponding to the DMRS port.

15. A base station, comprising:

the device comprises a determining module, a judging module and a judging module, wherein the determining module is used for determining a demodulation reference signal (DMRS) port of user equipment;

a transmitting module, configured to transmit a corresponding DMRS sequence through a DMRS port determined for the user equipment;

the acquisition module is specifically configured to:

determining a first orthogonal sequence corresponding to a DMRS port of the user equipment;

multiplying a first orthogonal sequence corresponding to N1 DMRS ports of the user equipment by-1 to obtain a second orthogonal sequence corresponding to N1 DMRS ports, wherein N1 is greater than or equal to 1 and is greater than or equal to N, and N is the number of the DMRS ports of the user equipment and is a positive integer;

and obtaining the DMRS sequences of the DMRS ports of the user equipment according to the second orthogonal sequences corresponding to the N1 DMRS ports and the first orthogonal sequences corresponding to the N2 DMRS ports, wherein N2 is N-N1.

16. The base station of claim 15, wherein the DMRS port is a DMRS port selected by the base station from a set of DMRS ports agreed with a user equipment.

17. The base station of claim 16, wherein after orthogonal sequences corresponding to some or all of the DMRS ports that occupy the same physical resources in the set of DMRS ports accumulate and sum orthogonal codes by position, the absolute value of the accumulated sum of orthogonal codes at each position is equal.

18. The base station of claim 17, wherein each orthogonal code in the orthogonal sequence has a value of 1 or-1.

19. The base station of claim 17, wherein if the number of ports occupying the same physical resource in the DMRS port set is K, and K is greater than or equal to 4, then orthogonal sequences corresponding to 4 ports of the K ports respectively are:

{ [ +1+1+1+1], [ +1-1+1-1], [ +1+1-1-1], [ -1+1+1-1] }, or,

{ [ +1+1+1+1], [ +1-1+1-1], [ -1-1+1+1], [ +1-1-1+1] }, or,

{ [ +1+1+1+1], [ -1+1-1+1], [ +1+1-1-1], [ +1-1-1+1] }, or,

{[-1-1-1-1],[+1-1+1-1],[+1+1-1-1],[+1-1-1+1]}。

20. a user device, comprising:

the acquisition module is used for acquiring a demodulation reference signal DMRS port;

the channel estimation module is used for estimating a downlink channel of the DMRS port according to the DMRS sequence;

the determining module is specifically configured to:

determining a first orthogonal sequence corresponding to the DMRS port;

multiplying the first orthogonal sequences corresponding to N1 DMRS ports by-1 to obtain second orthogonal sequences corresponding to N1 DMRS ports, wherein N1 is larger than or equal to 1 and is larger than or equal to N, and N is the number of the DMRS ports of the user equipment and is a positive integer;

21. The user equipment of claim 20, wherein the DMRS port is a DMRS port selected by a base station from a set of DMRS ports agreed with the user equipment.

22. The user equipment of claim 21, wherein after orthogonal sequences corresponding to some or all of the DMRS ports that occupy the same physical resource in the set of DMRS ports accumulate and sum orthogonal codes by position, an absolute value of an accumulated sum of orthogonal codes at each position is equal.

23. The user equipment of claim 22, wherein each orthogonal code in the orthogonal sequence takes on a value of 1 or-1.

24. The user equipment of claim 22, wherein if the number of ports occupying the same physical resource in the DMRS port set is K, and K ≧ 4, the orthogonal sequences corresponding to 4 ports of the K ports are respectively:

{ [ +1+1+1+1], [ +1-1+1-1], [ +1+1-1-1], [ -1+1+1-1] }, or,

{ [ +1+1+1+1], [ +1-1+1-1], [ -1-1+1+1], [ +1-1-1+1] }, or,

{ [ +1+1+1+1], [ -1+1-1+1], [ +1+1-1-1], [ +1-1-1+1] }, or,

{[-1-1-1-1],[+1-1+1-1],[+1+1-1-1],[+1-1-1+1]}。

25. the user equipment according to any of claims 20 to 24, wherein the channel estimation module is specifically configured to:

determining that the base station adopts the following DMRS port configuration scheme: configuring other DMRS ports except the DMRS port configured to the user equipment in the appointed port set to other user equipment, and performing downlink channel estimation according to the determined DMRS port configuration scheme; alternatively, the first and second electrodes may be,

determining that the base station adopts the following DMRS port configuration scheme: and configuring other DMRS ports occupying the same physical resources with the DMRS ports of the user equipment to other user equipment, and performing downlink channel estimation according to the determined DMRS port configuration scheme.