WO2017114050A1

WO2017114050A1 - Sending method and reception method for demodulation reference signal, terminal device, and base station

Info

Publication number: WO2017114050A1
Application number: PCT/CN2016/107383
Authority: WO
Inventors: 王坚; 李榕; 张朝龙; 乔云飞
Original assignee: 华为技术有限公司
Priority date: 2015-12-30
Filing date: 2016-11-26
Publication date: 2017-07-06
Also published as: CN106936551B; CN106936551A

Abstract

Disclosed in the present patent application are a sending method and a reception method for a demodulation reference signal, a terminal device, and a base station. The sending method comprises: a first terminal device maps a first demodulation reference signal of a first terminal device to a first subcarrier in a first time interval, the first subcarrier being one of at least two subcarriers used by a data signal of the first terminal device; and the first terminal device sends the first demodulation reference signal to the base station. In the present patent application, a demodulation reference signal can be sent by only using one subcarrier, and accordingly the present patent application is particularly applicable to a narrowband system.

Description

Transmission method and reception method of demodulation reference signal, terminal device and base station

This application claims priority to Chinese Patent Application No. 201511022738.9, entitled "Transmission Method and Receiving Method of Demodulation Reference Signal, Terminal Device and Base Station", submitted to the Chinese Patent Office on December 30, 2015. The entire content of which is incorporated herein by reference.

Technical field

The present patent application relates to the field of communications, and in particular to a method and a method for transmitting a demodulation reference signal. The patent application further relates to a terminal device and a base station.

Background technique

The 5G Internet of Things (IoT) technology puts forward higher requirements for cell coverage. For example, the coverage of Machine Type Communications (MTC) is required to have a gain of 20 dB compared to the traditional Long Term Evolution (LTE) communication. To meet this coverage requirement, the industry regards narrowband technology as an important candidate for implementing 5G IoT MTC.

In the communication system, the terminal device needs to insert a demodulation reference signal according to a certain rule in the uplink data, so that the base station can perform channel estimation according to the demodulation reference signal, and complete demodulation of the uplink data.

There are currently no demodulation reference signal transmission and reception schemes for narrowband systems.

Summary of the invention

The present patent application provides a method and a receiving method for transmitting a demodulation reference signal, a terminal device and a base station, which are suitable for transmitting and receiving demodulation reference signals of a narrowband system.

In a first aspect, the present application provides a method for transmitting a demodulation reference signal, including: mapping, by a first terminal device, a first demodulation reference signal of the first terminal device to a first time in a first time interval On the subcarrier, the first subcarrier is one of at least two subcarriers used by the data signal of the first terminal device; the first terminal device sends the first demodulation reference signal to the base station.

The demodulation reference signal of the terminal device is mapped to one of the at least two subcarriers used by the terminal device to transmit the data signal. The transmission of the demodulation reference signal can be realized by using only one subcarrier, and is particularly suitable for a narrowband system. This scheme can guarantee the uplink transmission of the narrowband system. And when transmitting the demodulation reference signal, only the demodulation reference signal is placed on one subcarrier at a time. Thus, the transmission of the demodulation reference signal is equivalent to a single carrier and has a lower peak-to-average power ratio (PAPR).

In conjunction with the first aspect, in a first possible implementation manner of the first aspect, the first terminal device maps the first demodulation reference signal of the first terminal device to a second in a second time interval On the subcarrier, the second subcarrier is one of at least two subcarriers used by the data signal of the first terminal device; the first subcarrier is different from the second subcarrier. This provides interpolation for the base station side, which makes it possible to obtain more accurate channel estimates.

With reference to the first aspect or the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the second sub-module of the second terminal device is further mapped on the first sub-carrier Reference signal. Demodulation reference signals of other terminal devices are also mapped on one of the first subcarriers. The superposition of the demodulation reference signals enables a plurality of terminal devices to transmit demodulation reference signals on the same time-frequency resource, that is, in the case of giving a total amount of timing resources, increasing the number of terminal devices accommodated by the system.

In conjunction with the second possible implementation of the first aspect, in a third possible implementation of the first aspect, the first demodulation reference signal and the second demodulation reference signal have a correlation.

In a second aspect, the present application provides a method for receiving a demodulation reference signal, the base station receiving a first demodulation reference signal from a first subcarrier at a first time interval, the first subcarrier being the first One of at least two subcarriers used by the data signal of the terminal device; the base station performs channel estimation on the first subcarrier by using the first demodulation reference signal to obtain a first channel of the first subcarrier And an estimated value, the first channel estimation value being a demodulation parameter of the data signal received by the first terminal device on the at least two subcarriers in the first time interval.

The base station receives a first demodulation reference signal from a first subcarrier, obtains a first channel estimation value using the first demodulation reference signal, and uses a first channel estimation value to solve a solution of the received data signal on the at least two subcarriers Adjust the parameters. It is only necessary to use one subcarrier to realize the transmission and reception of demodulation reference signals, especially for narrowband systems. This scheme can guarantee the uplink transmission of the narrowband system.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the base station receives a first demodulation reference signal from a second subcarrier at a second time interval, where the second subcarrier is Description One of at least two subcarriers used by the data signal of the first terminal device, the second subcarrier being different from the first subcarrier; the base station using the first demodulation reference signal for the second subcarrier Performing channel estimation to obtain a second channel estimation value of the second subcarrier, where the second channel estimation value is received by the first terminal device on the at least two subcarriers in the second time interval. Demodulation parameters of the data signal. Channel estimation using demodulation reference signals on different subcarriers at different time intervals can further ensure the accuracy of channel estimation and demodulation.

With reference to the first possible implementation of the second aspect, in a second possible implementation manner of the second aspect, the at least two subcarriers used by the data signal further includes a third subcarrier; And performing frequency domain interpolation on the first channel estimation value and the second channel estimation value to obtain a third channel estimation value, where the third channel estimation value is a demodulation parameter of the received data signal on the third subcarrier. Obtaining the third channel estimate by interpolating the two channel estimates further ensures the accuracy of channel estimation and demodulation.

With reference to the second aspect or the foregoing various possible implementation manners of the second aspect, in a third possible implementation manner of the second aspect, the second sub-interface of the second terminal device is further mapped on the first subcarrier Adjust the reference signal.

In conjunction with the third possible implementation of the second aspect, in a fourth possible implementation of the second aspect, the first demodulation reference signal and the second demodulation reference signal have a correlation.

In a third aspect, the present application provides a terminal device, including: a first processing unit, configured to map a first demodulation reference signal of a first terminal device to a first subcarrier in a first time interval, The first subcarrier is one of at least two subcarriers used by the data signal of the first terminal device, and the sending unit is configured to send the first demodulation reference signal to the base station.

With reference to the third aspect, in a first possible implementation manner of the third aspect, the first processing unit is further configured to map the first demodulation reference signal of the first terminal device to the second time interval On a second subcarrier, the second subcarrier is one of at least two subcarriers used by the data signal of the first terminal device; the first subcarrier is different from the second subcarrier.

With reference to the third aspect, or the first possible implementation manner of the third aspect, in a second possible implementation manner of the third aspect, the second demodulation reference of the other terminal device is further mapped on the first subcarrier signal.

In conjunction with the second possible implementation of the third aspect, in a third possible implementation of the third aspect, the first demodulation reference signal and the second demodulation reference signal have a correlation.

In a fourth aspect, the present application provides a base station, including: a receiving unit, configured to receive a first demodulation reference signal from a first subcarrier at a first time interval, where the first subcarrier is a first terminal One of the at least two subcarriers used by the data signal of the device; the second processing unit is configured to perform channel estimation on the first subcarrier by using the first demodulation reference signal, to obtain the first subcarrier And a first channel estimation value, where the first channel estimation value is a demodulation parameter of the data signal received by the first terminal device on the at least two subcarriers in the first time interval.

With reference to the fourth aspect, in a first possible implementation manner of the fourth aspect, the receiving unit is further configured to: receive a first demodulation reference signal from a second subcarrier at a second time interval, where The second subcarrier is one of at least two subcarriers used by the data signal of the first terminal device, and the second subcarrier is different from the first subcarrier; the processing unit is further configured to: use the first And demodulating the reference signal to perform channel estimation on the second subcarrier, to obtain a second channel estimation value of the second subcarrier, where the second channel estimation value is that the first terminal device is in the second time interval Demodulation parameters of the received data signals on the at least two subcarriers.

With reference to the first possible implementation of the fourth aspect, in a second possible implementation manner of the fourth aspect, the at least two subcarriers used by the data signal further includes a third subcarrier; The unit is further configured to perform frequency domain interpolation on the first channel estimation value and the second channel estimation value to obtain a third channel estimation value, where the third channel estimation value is a received data signal on the third subcarrier. Demodulation parameters.

In conjunction with the fourth aspect or the foregoing various possible implementation manners of the fourth aspect, in a third possible implementation manner of the fourth aspect, a second solution of the second terminal device is further mapped on the first subcarrier Adjust the reference signal.

In conjunction with the third possible implementation of the fourth aspect, in a fourth possible implementation of the fourth aspect, the first demodulation reference signal and the second demodulation reference signal have a correlation.

In a fifth aspect, the present patent application provides a terminal device, including: a transmitter; a first memory, configured to store an instruction; and a first processor connected to the first memory and the transmitter, respectively, for performing the The memory stores the instructions to perform the step of: mapping the first demodulation reference signal of the first terminal device to a first subcarrier during the first time interval, the first The subcarrier is one of at least two subcarriers used by the data signal of the first terminal device; the transmitter is configured to send the first demodulation reference signal to the base station.

With reference to the fifth aspect, in a first possible implementation manner of the fifth aspect, the first processor is further configured to map the first demodulation reference signal of the first terminal device to the second time interval On a second subcarrier, the second subcarrier is one of at least two subcarriers used by the data signal of the first terminal device; the first subcarrier is different from the second subcarrier.

With reference to the fifth aspect, or the first possible implementation manner of the fifth aspect, in a second possible implementation manner of the fifth aspect, the second demodulation reference of the other terminal device is further mapped on the first subcarrier signal.

In conjunction with the second possible implementation of the fifth aspect, in a third possible implementation of the fifth aspect, the first demodulation reference signal and the second demodulation reference signal have a correlation.

In a sixth aspect, the present application provides a base station, including: a receiver, configured to receive a first demodulation reference signal from a first subcarrier at a first time interval, where the first subcarrier is a first terminal One of at least two subcarriers used by the data signal of the device; a second memory for storing instructions; a second processor coupled to the receiver and the second memory, respectively, for performing the second memory storage The instruction, when performing the instruction, performing the following steps: performing channel estimation on the first subcarrier by using the first demodulation reference signal to obtain a first channel estimation value of the first subcarrier, The first channel estimation value is a demodulation parameter of a data signal received by the first terminal device on the at least two subcarriers at the first time interval.

With reference to the sixth aspect, in a first possible implementation manner of the sixth aspect, the receiver is further configured to: receive, at a second time interval, a first demodulation reference signal from a second subcarrier, where The two subcarriers are one of at least two subcarriers used by the data signal of the first terminal device, and the second subcarrier is different from the first subcarrier.

With reference to the sixth aspect, or the first possible implementation manner of the sixth aspect, in a second possible implementation manner of the sixth aspect, the at least two subcarriers used by the data signal further includes a third subcarrier; The second processor is further configured to perform frequency domain interpolation on the first channel estimation value and the second channel estimation value to obtain a third channel estimation value, where the third channel estimation value is on the third subcarrier. Demodulation parameters of the received data signal.

With the sixth aspect or the foregoing various possible implementation manners of the sixth aspect, in a third possible implementation manner of the sixth aspect, the second sub-device is further mapped on the first sub-carrier Adjust the reference signal.

In a fourth possible implementation manner of the sixth aspect, in a fourth possible implementation manner of the sixth aspect, the first demodulation reference signal and the second demodulation reference signal have a correlation.

DRAWINGS

In order to more clearly illustrate the technical patent application of the present patent application, the drawings to be used in the present patent application will be briefly described below. Obviously, the drawings described below are only some embodiments of the present patent application, Those skilled in the art can also obtain other drawings based on these drawings without paying any creative work.

1 is a block diagram of a wireless communication system in accordance with an embodiment of the present patent application.

2 is a schematic diagram of data modulation and mapping by a terminal device in accordance with another embodiment of the present patent application.

3 is a flow chart showing a method of transmitting a demodulation reference signal according to another embodiment of the present patent application.

4 is a schematic diagram of a terminal device performing demodulation reference signal mapping according to another embodiment of the present patent application.

FIG. 5 is a schematic flow chart of a method for transmitting a demodulation reference signal according to another embodiment of the present patent application.

6 is a schematic diagram of a terminal device performing demodulation reference signal mapping according to another embodiment of the present patent application.

FIG. 7 is a schematic flow chart of a method for receiving a demodulation reference signal by a base station according to another embodiment of the present patent application.

8 is a schematic diagram of a base station receiving a demodulation reference signal in accordance with another embodiment of the present patent application.

FIG. 9 is a flow chart showing a method for receiving a demodulation reference signal by a base station according to another embodiment of the present patent application.

10A and 10B are schematic diagrams of a base station receiving a demodulation reference signal in accordance with another embodiment of the present patent application.

11 is a schematic diagram of a terminal device according to another embodiment of the present patent application.

FIG. 12 is a schematic diagram of a base station according to another embodiment of the present patent application.

FIG. 13 is a schematic diagram of a terminal device according to another embodiment of the present patent application.

Figure 14 is a schematic diagram of a base station in accordance with another embodiment of the present patent application.

detailed description

The technical patent application in this patent application is clearly and completely described in the following with reference to the accompanying drawings in this patent application. It is obvious that the described embodiments are a part of the embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present patent application without the inventive work are all within the scope of the present patent application.

Referring now to Figure 1, a wireless communication system 100 in accordance with various embodiments described herein is illustrated. The wireless communication system 100 includes a base station 102 that can include multiple antenna groups. Each antenna group may include one or more antennas. For example, one antenna group may include

antennas

104 and 106, another antenna group may include

antennas

108 and 110, and additional groups may include

antennas

112 and 114. Two antennas are shown in Figure 1 for each antenna group, although more or fewer antennas may be used for each group. Base station 102 can additionally include a transmitter chain and a receiver chain, as will be understood by those of ordinary skill in the art, which can include various components associated with signal transmission and reception, such as processors, modulators, multiplexers, demodulation , demultiplexer or antenna.

Base station 102 can communicate with one or more access terminal devices, such as access terminal device 116 and access terminal device 122. However, it will be appreciated that base station 102 can communicate with any number of access terminal devices similar to access

terminal device

116 or 122.

Access terminal devices

116 and 122 may be, for example, cellular telephones, smart phones, portable computers, handheld communication devices, handheld computing devices, satellite radios, global positioning systems, personal digital assistants (PDAs), and/or Any other suitable device that communicates over the wireless communication system 100. As shown, access terminal device 116 is in communication with

antennas

112 and 114, wherein

antennas

112 and 114 transmit information to access terminal device 116 over forward link 118 and from access terminal device 116 through reverse link 120. Receive information. In addition, access terminal device 122 is in communication with

antennas

104 and 106, wherein

antennas

104 and 106 transmit information to access terminal device 122 over forward link 124 and receive information from access terminal device 122 over reverse link 126. In an FDD (Freq Terminal Equipment Ncy Division Duplex) system, for example, the forward link 118 can utilize different frequency bands than those used by the reverse link 120, and the forward link 124 can utilize and reverse chain Different frequency bands used by way 126. Moreover, in a TDD (Time Division Duplex) system, the forward link 118 and the reverse link 120 can use a common frequency band, and the forward link 124 and the reverse link 126 can use a common frequency band.

Each set of antennas and/or regions designed for communication is referred to as a sector of base station 102. For example, you can put the day The line set is designed to communicate with access terminal devices in sectors of the coverage area of base station 102. During base station 102 communication with

access terminal devices

116 and 122 via

forward links

118 and 124, respectively, the transmit antenna of base station 102 may utilize beamforming to improve the signal to noise ratio of

forward links

118 and 124. Furthermore, when the base station 102 uses beamforming to transmit signals to the randomly dispersed

access terminal devices

116 and 122 in the relevant coverage area, the neighboring cell is compared to the manner in which the base station transmits signals to all of its access terminal devices through a single antenna. Mobile devices in the middle are subject to less interference.

At a given time, base station 102, access terminal device 116 or access terminal device 122 may be a wireless communication transmitting device and/or a wireless communication receiving device. When transmitting data, the wireless communication transmitting device can encode the data for transmission. Specifically, the wireless communication transmitting device can acquire a certain number of data bits to be transmitted to the wireless communication receiving device through the channel. Acquisition can be, for example, generated, received from other communication devices, or saved in memory, and the like. Such data bits may be included in one or more transport blocks of data, and the transport blocks may be segmented to produce a plurality of code blocks.

The base station (BS) referred to in this patent application is a device deployed in a radio access network to provide a wireless communication function for a terminal device. The base station may include various forms of macro base stations, micro base stations, relay stations, access points, and the like. In a system using different radio access technologies, the name of a device having a base station function may be different. For example, in an LTE network, an evolved Node B (evolved Node B: eNB or eNodeB) is in the third. In the generation 3G network, it is called Node B (NodeB) and so on. For convenience of description, in the present patent application, the above-mentioned devices for providing wireless communication functions to terminal devices are collectively referred to as base stations or BSs.

In the LTE system, the Demodulation-Reference Signal (DM-RS) is placed in the time domain: in the case of a regular cyclic prefix (CP), the DM-RS appears in each sub-subs On the 4th and 11th symbols of the frame or in the case of the extended CP, on the 3rd and 9th symbols of each subframe; in the frequency domain, the DM-RS appears on all subcarriers where the terminal device data is located.

The subcarrier bandwidth in the existing LTE standard is 15 kHz. With the development of communication technology, a narrowband system has been proposed. A narrowband system is a communication system in which the effective bandwidth of the signal is much smaller than the carrier frequency or center frequency at which it is located. In a narrowband system, the bandwidth of each subcarrier is small, and the bandwidth can be 3.75 kHz or 2.25 kHz or 5 kHz.

The modulation and mapping of the data signals used in one embodiment of the present patent application is first described. First, data of a plurality of terminal devices is non-orthogonally superimposed on a plurality of narrowband subcarriers in an encoded manner. With The body may use Sparse Code Multiple Access (SCMA) or Low Density Signature (LDS) or Non-orthogonal Multiple Access (NOMA). As shown in FIG. 2, for a system using a 4×6 SCMA codebook, there are a total of four narrowband subcarriers of F1, F2, F3, and F4. The terminal device occupies the four narrow-band subcarriers according to the resource mapping positions indicated by the selected codebook. The data non-orthogonal superposition of a plurality of terminal devices is mapped on four narrow-band subcarriers of F1 to F4. When the number of terminal devices exceeds four, the system has an overload characteristic and high spectral efficiency. Figure 2 shows six terminal devices, U1, U2, U3, U4, U5, U6. Each terminal device occupies only 2 of the 4 narrowband subcarriers for data transmission according to the selected codebook. Optionally, the SCMA codebook with low PAPR may be used. According to different information bits sent by the terminal device, each terminal device places non-zero data in only one of the two narrow-band subcarriers occupied in each symbol interval. On top, another narrowband subcarrier transmits 0. Taking a 4-point codebook as an example, when the terminal device needs to transmit a bit of '00' or '11', a non-zero value is transmitted on the first sub-carrier of the two narrow-band subcarriers occupied by the terminal device. 0 is sent on each subcarrier. Similarly, if the bit to be transmitted is '01' or '10', 0 is transmitted on the first subcarrier, and a non-zero value is transmitted on the second subcarrier. Such a mapping manner enables each terminal device to use only one narrowband subcarrier to transmit data in each symbol interval, and the PAPR is lower, which is the same as the single carrier system. Of course, it is also possible to use a codebook with a low PAPR.

3 is a flow chart showing a method of transmitting a demodulation reference signal according to another embodiment of the present patent application. As shown in FIG. 3, the method includes the following steps:

301. The first terminal device maps the first demodulation reference signal of the first terminal device to a first subcarrier in a first time interval. The first subcarrier is one of at least two subcarriers used by the data signal of the first terminal device.

302. The first terminal device sends a first demodulation reference signal to the base station.

As shown in FIG. 4, in the system using four subcarriers F1, F2, F3, and F4, the terminal device terminal device 1 is taken as an example, and the data signals use two subcarriers F1 and F2. The subcarrier may be determined by a codebook selected by the terminal device or by other means. In the frequency domain, the demodulation reference signal is mapped to one of the first subcarriers of F1 and F2. In this embodiment, the first first subcarrier is fixed, specifically F1. In the time domain, the demodulation reference signals are arranged on the time axis, and every other pilot transmission interval is repeated once, each time for a certain period of time. The duration of the demodulation reference signal can be related to the demodulation reference signal length. In this patent application, the demodulation reference signals are arranged in time rather than in the frequency domain, which allows a system with fewer subcarriers to properly place and transmit demodulation reference signals. Here "sub-load The number of subcarriers is less than the number of subcarriers of one resource block of the LTE system. It should be noted that the demodulation reference signal in this patent application is not transmitted in a communication system with fewer subcarriers. .

Similarly, for the terminal device terminal device 2 - the terminal device 6, its first demodulation reference signal is mapped onto a first subcarrier. The first subcarrier is one of at least two subcarriers used by the data signal of the first terminal device.

It can be seen that for 4 subcarrier systems, all 4 subcarriers are occupied by one or several terminal devices. Demodulation reference signals of a plurality of terminal devices may be superimposed. Demodulation reference signals of other terminal devices are also mapped on one of the first subcarriers. The superposition of the demodulation reference signals enables a plurality of terminal devices to transmit demodulation reference signals on the same time-frequency resource, that is, in the case of giving a total amount of timing resources, increasing the number of terminal devices accommodated by the system.

As shown in FIG. 4, the first subcarrier F1 superimposes the demodulation reference signals of the first terminal device terminal device 1 and the third terminal device terminal device 3. The demodulation reference signals of the two terminal devices are mapped to the same subcarrier. More generally, the demodulation reference signals of a plurality of terminal devices can be superimposed.

At least two demodulation reference signals mapped on one first subcarrier have correlation. Optionally, at least two demodulation reference signals mapped on one first subcarrier have orthogonality. A Zadoff-Chu (ZC) sequence can be used as the demodulation reference signal.

In the present application, there is no particular limitation on the number of terminal devices that simultaneously transmit demodulation reference signals in the system. The superposition of the demodulation reference signal causes a certain loss in the performance of subsequent processing, such as demodulation reference signal detection, channel estimation, etc., although although the patent application does not limit the number of concurrent demodulation reference signals, the actual system design time It is necessary to comprehensively consider the impact of performance. In this case, the length and number of demodulation reference signals need to be selected according to the number of terminal devices that need to be supported during system design.

By demodulating the reference signal superposition, the resource utilization of the demodulation reference signal portion is improved, and the system can accommodate more terminal devices at the same time, thereby improving the system capacity.

In the present patent application, when the demodulation reference signal is transmitted, only the demodulation reference signal is placed on a first subcarrier at a time. Thus, the transmission of the demodulation reference signal is equivalent to a single carrier and has a lower PAPR.

In the present patent application, there is no particular limitation on the length of the demodulation reference signal sequence, that is, the demodulation reference signal can be arbitrarily long if the system resource utilization requirement permits.

Optionally, in 301, the first demodulation reference signal is selected from the demodulation reference signal set. of. The selection method may be a random selection or a selection according to a certain rule.

The above method is particularly suitable for narrowband systems. In a narrowband system, the bandwidth of each subcarrier is small, and the coherence bandwidth of the channel is much larger than the bandwidth of the subcarrier. The base station performs channel estimation on the first subcarrier by using a demodulation reference signal received from a first subcarrier, and obtains a channel estimation value of the first subcarrier, and uses the channel estimation value of the first first subcarrier. Demodulate all data signals of the terminal device. This reduces the number of subcarriers used while ensuring full demodulation of the data of the terminal equipment on other subcarriers.

In the present patent application, the method of transmitting the demodulation reference signal can be applied in a narrowband SCMA system. Of course, those skilled in the art should be aware that the transmission method of the demodulation reference signal can also be applied to other systems.

FIG. 5 illustrates a method of transmitting a demodulation reference signal in accordance with another embodiment of the present patent application. As shown in FIG. 5, the main difference between the method and the method shown in FIG. 1 is: step 501.

As shown in FIG. 5, the method includes the following steps:

501. The first terminal device maps the first demodulation reference signal of the first terminal device to a first subcarrier in a first time interval. The first subcarrier is one of at least two subcarriers used by the data signal of the first terminal device. The first terminal device maps the first demodulation reference signal of the first terminal device to a second subcarrier in a second time interval. The second subcarrier is one of at least two subcarriers used by the data signal of the first terminal device. The first subcarrier is different from the second subcarrier.

The demodulation reference signal hops at different time intervals in at least two subcarriers used by the data signal. This time interval can be understood as a frequency hopping interval. The hopping interval may correspond to one "frame" or one "subframe" or multiple "frames" or multiple "subframes". Each time the mapping is performed, the demodulation reference signal is mapped onto one of the at least two subcarriers. But at different hop intervals, the demodulation reference signal can be mapped to different ones of the at least two subcarriers. This change can be periodic.

502. Basically similar to step 302.

FIG. 6 shows that one terminal carrier used by the terminal device terminal device 1 when transmitting demodulation reference signals changes with time intervals. As shown in FIG. 6, the terminal device terminal device 1 is taken as an example, and the data signals use two subcarriers F1 and F2. At the first hop interval, the demodulation reference signal is mapped to one of the two subcarriers F1 and F2, which is F1 in this embodiment. In the second hop interval, the demodulation reference signal is mapped to one of the two subcarriers of F1 and F2. In this embodiment In the middle is F2. This can be a period, switching on at least two subcarriers. For other terminal devices, the processing thereof is also similar to the terminal device terminal device 1.

Since the demodulation reference signal of a given terminal device hops on at least two subcarriers, channel estimation results in multiple hopping intervals can be interpolated in both the time domain and the frequency domain during channel estimation, so that channel estimation is performed. The result is better tracking of channel changes in the time domain and frequency domain.

As shown in FIG. 7, according to another embodiment of the present patent application, a method for receiving a demodulation reference signal includes the following steps:

701. The base station receives a first demodulation reference signal from a first subcarrier at a first time interval, where the first subcarrier is one of at least two subcarriers used by the data signal of the first terminal device.

702. The base station performs channel estimation on the first subcarrier by using the first demodulation reference signal to obtain a first channel estimation value of the first subcarrier. The first channel estimate is a demodulation parameter of the data signal received by the first terminal device from all subcarriers at a first time interval. The first channel estimate may demodulate all data signals of the terminal device. The entire data signal occupies multiple subcarriers.

The receiving method can also process the first demodulation reference signal to determine which demodulation reference signals are transmitted by the terminal device. This completes the terminal device detection. Taking the ZC sequence as the demodulation reference signal as an example, the process of detecting the terminal device may be as follows: since the base station knows the demodulation reference signal set, it only needs to receive the demodulation reference signal and the locally known demodulation reference signal set. All demodulation reference signals are respectively related to the operation. Taking the 4 subcarrier system as an example, the receiving demodulation reference signal on the first subcarrier is y ₁ , and there are N demodulation reference signals in the local demodulation reference signal set, which are recorded as {p ₁ p ₂ ... p _N }, related operations are performed on all sequences in y ₁ and {p ₁ p ₂ ... p _N }. If the absolute value of the result r _k associated with p _k , k ∈ {1, 2, ..., N} is greater than a certain threshold value, the demodulation reference signal p _k is transmitted. That is, there is a terminal device in the system, and the demodulation reference signal p _{k is} transmitted. This threshold can be given by standard or set in advance. In the case where the demodulation reference signals of other terminal devices are also mapped on one of the at least two subcarriers, that is, in the case where the demodulation reference signals are allowed to be superimposed, {p ₁ p ₂ may occur in the related operation. ...p _N } is the case where multiple sequences are transmitted, which means that the demodulation reference signals of a plurality of terminal devices are superimposed on the subcarrier.

In 702, taking the ZC sequence as a demodulation reference signal as an example, similar to the processing of the terminal device detection, when the demodulation reference signal is received and related to all demodulation reference signals in the local demodulation reference signal set, the correlation is obtained. The value is the channel estimate. For example, correlating the received demodulation reference signal y ₁ on the first subcarrier with all demodulation reference signals in the local demodulation reference signal set {p ₁ p ₂ ... p _N }, and p _k , k ∈ { 1, 2, ..., N} The result of the correlation r _k is greater than a certain threshold, indicating that the terminal device transmits the demodulation reference signal p _k , and the correlation result r _k is the terminal device on the subcarrier. Channel estimate.

The base station uses the channel estimation value of each terminal device on a first subcarrier for the decoding of the data part, and obtains the information sent by the terminal device. The channel estimate on a first subcarrier can be used for demodulation of data on multiple subcarriers. As shown in FIG. 8, the terminal device uses a fixed demodulation reference signal transmission scheme, and transmits a first demodulation reference signal on the first subcarrier F1, and transmits on the first subcarrier F1 and the second subcarrier F2. The data, the channel estimation value h obtained from the demodulation reference signal portion, can be directly used for decoding the data on the first and second subcarriers. For two time intervals, the channel estimate obtained in the first time interval is h ₁ and the channel estimate in the second time interval is h ₂ . The data portion of the first time interval can be demodulated directly using h ₁ , and the data in the second time interval can be demodulated using h ₂ .

In this embodiment, the method for receiving the demodulation reference signal may further include the step 703, the base station performing interpolation processing on the at least two first channel estimation values. Specifically, the base station may perform interpolation processing on the result of multiple detections of one terminal device. For example, after obtaining a channel estimation value h _{1 of the} terminal device in the first time interval and h _{2 in the} second time interval, the time domain interpolation processing may be performed, and the interpolation result is

Where the function symbol f(·) is a time domain interpolation function, using channel estimation after time domain interpolation

The data portion between the first time interval and the second time interval is demodulated. The above is an example of two-point interpolation. It is also possible to record N channel estimation values h _n , n=1, 2, . . . , N, and perform multi-point time domain interpolation. This can better track changes in the channel over time.

As shown in FIG. 9, according to another embodiment of the present patent application, a method of receiving a demodulation reference signal is provided. This embodiment corresponds to a scheme in which the terminal device uses frequency hopping transmission. The method includes:

901-902 is basically the same as 701-702.

903. The base station receives a first demodulation reference signal from a second subcarrier at a second time interval, where the second subcarrier is one of at least two subcarriers used by the data signal of the first terminal device. The second subcarrier is different from the first subcarrier.

904. The base station performs channel estimation on the second subcarrier by using the first demodulation reference signal to obtain a second channel estimation value of the second subcarrier. The second channel estimate is a demodulation parameter of the data signal received by the first terminal device from all of the subcarriers at the second time interval. The second channel estimate may demodulate all data signals during the second time interval of the terminal device. The entire data signal occupies multiple subcarriers wave.

In this embodiment, the method for receiving the demodulation reference signal may further include the step 905, the base station performing interpolation processing on the at least two first channel estimation values.

If the terminal device adopts a scheme of frequency hopping transmission, the channel estimation value in each hopping interval can be used for demodulation of data in the interval, that is, the channel estimation value h ₁ of the first hopping interval in FIG. 10A is used. Data demodulation of the first hop interval, and channel estimation value h _{2 of the} second hop interval is used for data demodulation in the second hop interval. The base station may also combine the results of multiple detections by one terminal device, and perform the interpolation processing on the results of the multiple channel estimation. For the time domain interpolation, you can refer to the above description.

If the terminal device adopts a frequency hopping transmission scheme, in addition to the above-mentioned time domain interpolation, frequency domain interpolation can also be performed. For example, as shown in FIG. 10B, one terminal device uses three subcarriers for data transmission, and also places a demodulation reference signal on one of three subcarriers for transmission each time. In the first hop interval, the channel estimation value of the first subcarrier F1 is obtained as h ₁ , and the channel estimation value h _{3 of the} third subcarrier is obtained in the second hop interval for frequency domain interpolation.

The function symbol w(·) is a frequency domain interpolation function. The first channel estimate after frequency domain interpolation can be obtained.

Second channel estimate after frequency domain interpolation

Third channel estimate after frequency domain interpolation

use

Demodulating data on the first subcarrier F1 in the first hop interval and the second hop interval,

Demodulating data on the second subcarrier F2 in the first hop interval and the second hop interval,

The data on the third subcarrier F3 in the first hop interval and the second hop interval is demodulated. Similarly, multi-point frequency domain interpolation is also possible.

The base station may also perform time offset and frequency offset estimation using the demodulation reference signal to obtain a time offset and a frequency offset value of the terminal device corresponding to the demodulated reference signal, that is, a completion time offset estimation and a frequency offset estimation.

This patent application further provides an apparatus embodiment for implementing the steps and methods of the above method embodiments.

As shown in FIG. 11, according to another embodiment of the present patent application, a terminal device 1100 includes a first processor 1160 and a first transmitter 1110 coupled to each other.

In one embodiment, the first processor 1160 maps the first demodulation reference signal of the first terminal device onto a first subcarrier during the first time interval. The first subcarrier is one of at least two subcarriers used by the data signal of the first terminal device.

The first transmitter 1110 transmits the first demodulation reference signal to the base station.

The first transmitter 1110 is located in the RF module 1112. RF module for modulating the baseband signal After being upconverted, filtered, and power amplified, it is sent out through the antenna.

The terminal device 1100 can also include a memory 1120 that is coupled to the first processor 1160. The memory 1120 stores an instruction, and the first processor 1160 executes the instruction to perform the method of transmitting the demodulation reference signal.

The terminal device 1100 can also include an input unit 1130 that can be used to receive input numeric or character information and to generate signal inputs related to user settings and function control of the terminal device 1100. Specifically, in the embodiment of the present invention, the input unit 1130 may include a touch panel 1131. The touch panel 1131, also referred to as a touch screen, can collect touch operations on or near the user (such as the operation of the user using a finger, a stylus, or the like on the touch panel 1131 or the touch panel 1131. ), and drive the corresponding connection device according to a preset program. Optionally, the touch panel 1131 may include two parts: a touch detection device and a touch controller. Wherein, the touch detection device detects the touch orientation of the user, and detects a signal brought by the touch operation, and transmits the signal to the touch controller; the touch controller receives the touch information from the touch detection device, converts the touch information into contact coordinates, and sends the touch information. The first processor 1160 is provided and can receive commands from the first processor 1160 and execute them. In addition, the touch panel 1131 can be implemented in various types such as resistive, capacitive, infrared, and surface acoustic waves. In addition to the touch panel 1131, the input unit 1130 may further include other input devices 1132. The other input devices 1132 may include but are not limited to physical keyboards, function keys (such as volume control buttons, switch buttons, etc.), trackballs, mice, joysticks, and the like. One or more of them.

The terminal device 1100 may further include a display unit 1140 that can be used to display information input by the user or information provided to the user and various menu interfaces of the terminal device 1100. The display unit 1140 can include a display panel 1141. Alternatively, the display panel 1141 can be configured in the form of an LCD (Liquid Crystal Display) or an OLED (Organic Light-Emitting Diode).

The terminal device 1100 may further include a power source 1190 to supply power to the entire terminal device 1100. The terminal device 1100 may further include an audio circuit 1170 that processes audio signals of the entire terminal device.

In another embodiment, the first processor 1160 maps the first demodulation reference signal of the first terminal device to a first subcarrier during the first time interval. The first subcarrier is one of at least two subcarriers used by the data signal of the first terminal device. The first processor 1160 maps the first demodulation reference signal of the first terminal device to a second subcarrier in a second time interval. The second subcarrier is one of at least two subcarriers used by the data signal of the first terminal device. First subcarrier and The two subcarriers are different.

As shown in FIG. 12, in accordance with another embodiment of the present patent application, a base station 1200 includes a second processor 1202 and a receiver 1201 coupled to each other.

In one embodiment, the receiver 1201 receives the first demodulation reference signal from a first subcarrier at a first time interval, the first subcarrier being the at least two subcarriers used by the data signal of the first terminal device One.

The second processor 1202 performs channel estimation on the first subcarrier by using the first demodulation reference signal to obtain a first channel estimation value of the first subcarrier. The first channel estimate is a demodulation parameter of the data signal received by the first terminal device from all subcarriers at a first time interval. The first channel estimate may demodulate all data signals on the at least two subcarriers of the terminal device.

The receiver 1201 is configured to support the base station to transmit and receive information with the terminal device in the above embodiment, and to support the terminal device to perform radio communication with other terminal devices. The second processor 1202 performs various functions for communicating with the terminal device. On the uplink, the uplink signal from the terminal device is received via the antenna, coordinated by the receiver 1201, and further processed by the second processor 1202 to recover the service data and signaling information transmitted by the terminal device. The second processor 1202 also performs the processes involved in the base station of Figures 7 and 9 and/or other processes for the techniques described herein. The memory 1203 is used to store program codes and data of the base station.

It will be appreciated that Figure 12 only shows a simplified design of the base station. In practical applications, the base station may include any number of transmitters, receivers, processors, controllers, memories, communication units, etc., and all base stations that can implement the present invention are within the scope of the present invention.

As shown in FIG. 13, a terminal device 1300 includes: a first processing unit 1302, configured to map a first demodulation reference signal of a first terminal device to a first subcarrier in a first time interval, where The first subcarrier is one of at least two subcarriers used by the data signal of the first terminal device, and the sending unit 1301 is configured to send the first demodulation reference signal to the base station.

The first processing unit 1302 is further configured to map the first demodulation reference signal of the first terminal device to a second subcarrier in a second time interval, where the second subcarrier is the first One of at least two subcarriers used by the data signal of the terminal device; the first subcarrier is different from the second subcarrier.

As shown in FIG. 14, a base station 1400 includes: a receiving unit 1401, configured to receive a first demodulation reference signal from a first subcarrier at a first time interval, where the first subcarrier is a first terminal device One of the at least two subcarriers used by the data signal; the second processing unit 1402, configured to perform channel estimation on the first subcarrier by using the first demodulation reference signal, to obtain the first subcarrier And a first channel estimation value, where the first channel estimation value is a demodulation parameter of the data signal received by the first terminal device on the at least two subcarriers in the first time interval.

The receiving unit 1401 is further configured to: receive, at a second time interval, a first demodulation reference signal from a second subcarrier, where the second subcarrier is at least two used by the data signal of the first terminal device One of the subcarriers, the second subcarrier being different from the first subcarrier; the processor is further configured to: perform channel estimation on the second subcarrier by using the first demodulation reference signal, to obtain the a second channel estimate of the second subcarrier, the second channel estimate being a demodulation parameter of the data signal received by the first terminal device on the at least two subcarriers at the second time interval.

The at least two subcarriers used by the data signal further include a third subcarrier; the second processing unit 1402 is further configured to: perform frequency domain interpolation on the first channel estimation value and the second channel estimation value to obtain a first A three channel estimate, the third channel estimate being a demodulation parameter of the received data signal on the third subcarrier.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technology patent application. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of this patent application.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated as The components displayed by the unit may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. The purpose of the patent application of this embodiment can be achieved by selecting some or all of the units according to actual needs.

In addition, each functional unit in each embodiment of the present patent application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on such understanding, the portion of the technical patent application of the present patent application that contributes essentially or to the prior art or the portion of the technical patent application can be embodied in the form of a software product stored in a storage medium. A number of instructions are included to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present patent application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like. .

The above is only a specific embodiment of the present patent application, but the scope of protection of the present patent application is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed in the patent application. Substitutions are intended to be covered by the scope of this patent application. Therefore, the scope of protection of this patent application should be determined by the scope of the claims.

Claims

A method for transmitting a demodulation reference signal, comprising:

The first terminal device maps the first demodulation reference signal of the first terminal device to a first subcarrier in a first time interval, where the first subcarrier is a data signal of the first terminal device One of at least two subcarriers used;

The first terminal device sends the first demodulation reference signal to a base station.
The transmitting method according to claim 1, further comprising:

Mapping, by the first terminal device, the first demodulation reference signal of the first terminal device to a second subcarrier, where the second subcarrier is data of the first terminal device One of at least two subcarriers used by the signal; the first subcarrier is different from the second subcarrier.
The transmitting method according to claim 1 or 2, characterized in that:

A second demodulation reference signal of the second terminal device is further mapped on the first subcarrier.
The transmitting method according to claim 3, wherein the first demodulation reference signal and the second demodulation reference signal have a correlation.
A method for receiving a demodulation reference signal, comprising:

Receiving, by the base station, a first demodulation reference signal from a first subcarrier at a first time interval, where the first subcarrier is one of at least two subcarriers used by the data signal of the first terminal device;

The base station performs channel estimation on the first subcarrier by using the first demodulation reference signal to obtain a first channel estimation value of the first subcarrier, where the first channel estimation value is the first terminal A demodulation parameter of the data signal received by the device on the at least two subcarriers at the first time interval.
The method for receiving a demodulation reference signal according to claim 5, further comprising:

Receiving, by the base station, a first demodulation reference signal from a second subcarrier at a second time interval, where the second subcarrier is one of at least two subcarriers used by the data signal of the first terminal device, The second subcarrier is different from the first subcarrier;

The base station performs channel estimation on the second subcarrier by using the first demodulation reference signal to obtain a second channel estimation value of the second subcarrier, where the second channel estimation value is the first terminal A demodulation parameter of the data signal received by the device on the at least two subcarriers at the second time interval.
The method for receiving a demodulation reference signal according to claim 6, wherein at least two subcarriers used by said data signal further comprise a third subcarrier; said method further comprising: estimating said first channel The value and the second channel estimate are frequency domain interpolated to obtain a third channel estimate, the third channel estimate being a demodulation parameter of the received data signal on the third subcarrier.
A terminal device, comprising:

Transmitter;

a first memory for storing instructions;

The first processor is coupled to the first memory and the transmitter, respectively, for executing the instruction stored by the first memory to perform the following steps when executing the instruction:

Mapping the first demodulation reference signal of the first terminal device to a first subcarrier, where the first subcarrier is at least two subcarriers used by the data signal of the first terminal device one of the;

The transmitter is configured to send the first demodulation reference signal to a base station.
The terminal device according to claim 8, wherein:

The first processor is further configured to map the first demodulation reference signal of the first terminal device to a second subcarrier in a second time interval, where the second subcarrier is the first terminal One of at least two subcarriers used by the data signal of the device; the first subcarrier is different from the second subcarrier.
A terminal device according to claim 8 or 9, wherein:

A second demodulation reference signal of another terminal device is further mapped on the first subcarrier.
The terminal device according to claim 10, characterized in that:

There is a correlation between the first demodulation reference signal and the second demodulation reference signal.
A base station, comprising:

a receiver, configured to receive, at a first time interval, a first demodulation reference signal from a first subcarrier, where the first subcarrier is one of at least two subcarriers used by a data signal of the first terminal device;

a second memory for storing instructions;

a second processor, coupled to the receiver and the second memory, for executing the instructions stored by the second memory to perform the following steps when executing the instructions:

Performing channel estimation on the first subcarrier by using the first demodulation reference signal to obtain a first channel estimation value of the first subcarrier, where the first channel estimation value is that the first terminal device is in the Demodulating parameters of the data signals received on the at least two subcarriers at a first time interval.
A base station according to claim 12, wherein:

The receiver is further configured to: receive, at a second time interval, a first demodulation reference signal from a second subcarrier, where the second subcarrier is at least two sub-uses used by the data signal of the first terminal device One of the carriers, the second subcarrier being different from the first subcarrier.
A base station according to claim 13 wherein:

The at least two subcarriers used by the data signal further include a third subcarrier; the second processor is further configured to perform frequency domain interpolation on the first channel estimation value and the second channel estimation value to obtain a third a channel estimation value, the third channel estimation value being a demodulation parameter of the received data signal on the third subcarrier.