CN112073341B - Method and system for estimating self-interference channel of full-duplex digital domain - Google Patents
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Abstract
The invention discloses a method and a system for estimating a full-duplex digital domain self-interference channel, wherein the method comprises the following steps: respectively allocating two adjacent time slot resources for the network mode I and the network mode II; the resource blocks corresponding to the network mode I and the network mode II are respectively used for respective frequency band resources and are aligned in time; based on the allocated time slot resources, finishing pilot frequency mapping of the reference signals by adopting a time division multiplexing mode; channel state information estimation is carried out on the basis of the mapped reference signals in a first network mode stage and a second network mode stage respectively to obtain channel state information of a plurality of uplink channels and intermodulation interference channels; and respectively carrying out frequency domain mean value filtering on the channel state information of the plurality of uplink channels and the intermodulation interference channels to obtain the optimized channel state information of the uplink channels and the optimized channel state information of the intermodulation interference channels. The invention can accurately estimate the channel state information of the self-interference channel and the uplink channel, and provides reference and support for subsequent interference elimination work.
Description
Technical Field
The invention relates to the technical field of intermodulation self-interference elimination of a multi-carrier system, in particular to a method and a system for estimating a full-duplex digital domain self-interference channel.
Background
Due to the nonlinear characteristic of a radio frequency device, the increasingly depleted reliable spectrum resources and other factors, the multi-carrier system of the terminal such as the Orthogonal Frequency Division Multiplexing (OFDM) has the potential problem of intermodulation self-interference, especially under the NSA architecture of the non-independent network, the LTE and the 5G NR face the serious self-interference problem in the existing spectrum planning, especially the intermodulation self-interference of the uplink transmitting end to the downlink receiving end radiated by the PCB. In order to be compatible with the existing spectrum planning and protocol requirements, relevant measures must be taken to inhibit the self-interference of the receiving end and avoid the sensitivity rollback problem. The current solutions to the intermodulation self-interference problem include the following:
1) optimizing radio frequency device linearity performance
The nonlinear effects of radio frequency devices, especially power amplifiers, are the root cause of intermodulation interference. Aiming at devices of different types, related technical indexes are researched and optimized, and schemes such as predistortion and the like are designed so as to reduce nonlinear effects of the devices. However, the optimization of the device performance is a long-term research and development work, and different devices need to be matched, so the implementation cost of the scheme is high.
2) Adding interference cancellation modules
Reference is made to full-duplex self-interference cancellation methods, such as spatial domain self-interference cancellation, analog domain cancellation and digital domain cancellation. The airspace self-interference elimination utilizes parameters such as natural isolation, directivity and freedom degree of the antenna to reduce the power of a self-interference signal entering a receiver through digital and analog operations. And the self-interference elimination in the analog domain reconstructs a self-interference signal by designing an analog circuit, and then the self-interference signal is subtracted from a receiving signal at the front end of the receiver, so that the analog self-interference suppression is realized. And the self-interference elimination in the digital domain models and estimates the channel of the self-interference, and the reconstructed self-interference is subtracted from the received signal to realize interference cancellation. The feasibility of intermodulation interference cancellation in the analog domain needs further investigation and the cancellation method inevitably introduces new interference problems.
3) Time-frequency scheduling
Commonly used resource scheduling is divided into frequency selective scheduling and time division scheduling. The main principle of downlink frequency selection scheduling is to allocate better sub-band resources to users in the frequency domain according to Channel State Information (CSI) of a downlink channel fed back by the users. The essential idea is to optimize the link performance by using the degree of freedom of the quality change of the wireless channel in the frequency domain, and avoid the interference between cells. The time division scheduling is distributed according to the ratio of uplink and downlink time slots, the network gives the ratio of the uplink and downlink time slots, and the terminal reasonably controls the transceiving according to the ratio. For example, when the terminal has an intermodulation interference problem, reception may be suspended on the reception side for a period of time avoiding the presence of intermodulation interference. However, time-frequency scheduling needs to suspend transmission or reception work at a certain end according to the conditions of interference strength, time slot ratio and the like, and even involves a more complex network transformation problem, which reduces the throughput of the system and affects the peak rate of the network.
Disclosure of Invention
The invention provides a method and a system for estimating a self-interference channel in a full-duplex digital domain, aiming at solving the problem of intermodulation interference caused by the propagation of a PCB leakage interference channel, accurately estimating Channel State Information (CSI) of the self-interference channel and an uplink channel, and providing reference and support for the subsequent interference elimination work.
In order to solve the technical problems, the invention provides the following technical scheme:
in one aspect, the present invention provides a full-duplex digital domain self-interference channel estimation method, which includes:
respectively allocating two adjacent time slot resources for the network mode I and the network mode II; the resource blocks corresponding to the network mode I and the network mode II are respectively used for respective frequency band resources and are aligned in time;
based on the allocated time slot resources, finishing pilot frequency mapping of the reference signals by adopting a time division multiplexing mode;
channel state information estimation is carried out on the basis of the mapped reference signals in a first network mode stage and a second network mode stage respectively to obtain channel state information of a plurality of uplink channels and intermodulation interference channels;
and respectively carrying out frequency domain mean value filtering on the channel state information of the plurality of uplink channels and the intermodulation interference channels to obtain the optimized channel state information of the uplink channels and the optimized channel state information of the intermodulation interference channels.
Further, based on the allocated time slot resources, the pilot mapping of the reference signal is completed in a time division multiplexing manner, including:
in the channel estimation stage of the network mode one, mapping a network mode one reference signal RS1 for uplink channel estimation on the selected symbols and resource elements; mapping a network mode one reference signal RS2 for the intermodulation interference channel estimation on the resource particles of the rest symbols, and simultaneously mapping a network mode two reference signal RS3 for the intermodulation interference channel estimation on the same symbol position on the aligned time slot corresponding to the network mode two; RS2 and RS3 simultaneously pass through a nonlinear system to generate an intermodulation process and a first intermodulation reference signal;
in the phase of network mode two channel estimation, mapping a network mode two reference signal RS4 used for uplink channel estimation on the selected symbols and resource elements; mapping network mode two reference signals RS5 for the intermodulation interference channel estimation on the resource particles of the rest symbols, and simultaneously mapping network mode one reference signal RS6 for the intermodulation interference channel estimation on the same symbol position on the corresponding aligned time slot of the network mode one; RS5 and RS6 simultaneously pass through the nonlinear system, generating an intermodulation process and a second intermodulation reference signal.
Further, channel state information estimation is performed in a network mode first stage and a network mode second stage respectively based on the mapped reference signals, and channel state information of a plurality of uplink channels and intermodulation interference channels is obtained, which includes:
in a channel estimation stage of a first network mode, columnar pilot frequency is inserted into a subframe in a time division multiplexing mode, meanwhile, columnar pilot frequency is inserted into a subframe of a second network mode in an auxiliary mode, channel state information CSI1 of an uplink channel of the first network mode is obtained based on RS1 estimation, channel state information CSI2 of the uplink channel of the second network mode is obtained based on RS3, and channel state information CSI3 of an intermodulation interference channel is obtained based on a first intermodulation reference signal;
in the channel estimation stage of the network mode two, the columnar pilot frequency is inserted into the subframe in a time division multiplexing mode, meanwhile, the columnar pilot frequency is inserted into the subframe of the network mode one in an auxiliary mode, channel state information CSI4 of an uplink channel of the network mode two is obtained based on RS4 estimation, channel state information CSI5 of the uplink channel of the network mode one is obtained based on RS6, and channel state information CSI6 of an intermodulation interference channel is obtained based on the second intermodulation reference signal.
Further, performing frequency domain mean filtering on the channel state information of the plurality of uplink channels and the intermodulation interference channels respectively to obtain the channel state information of the optimized uplink channel and the channel state information of the optimized intermodulation interference channel, including:
averaging the CSI3 and the CSI6 on each resource particle to realize frequency domain average filtering and obtain the channel state information of the optimized intermodulation interference channel;
averaging resource particles of CSI1 and CSI5 to realize frequency domain average filtering to obtain channel state information of an uplink channel of an optimized network mode I;
and averaging resource particles of the CSI2 and CSI4 to realize frequency domain average filtering, so as to obtain the channel state information of the uplink channel of the optimized network mode two.
Further, the method for estimating the channel state information of the intermodulation interference channel comprises:
performing discrete Fourier transform on the frequency domain information obtained by receiving and demodulating to obtain a first transform signal;
zeroing the first transformation signal to realize signal denoising and obtain a signal after the dryness removal;
and performing inverse Fourier transform twice on the signal after the dryness removal, and then performing time domain denoising operation on the signal after the inverse Fourier transform twice so as to complete the calculation of the channel state information of the intermodulation interference channel.
In another aspect, the present invention further provides a full-duplex digital domain self-interference channel estimation system, which includes:
the frame structure design module is used for respectively allocating two adjacent time slot resources for the network mode I and the network mode II; the resource blocks corresponding to the network mode I and the network mode II are respectively used for respective frequency band resources and are aligned in time;
the pilot frequency mapping module is used for finishing the pilot frequency mapping of the reference signal in a time division multiplexing mode based on the allocated time slot resources;
a channel state information estimation module, configured to perform channel state information estimation in a network mode first stage and a network mode second stage, respectively, based on the mapped reference signal, to obtain channel state information of a plurality of uplink channels and intermodulation interference channels;
and the estimation result optimization module is used for respectively carrying out frequency domain mean value filtering on the channel state information of the plurality of uplink channels and the intermodulation interference channels to obtain the optimized channel state information of the uplink channels and the optimized channel state information of the intermodulation interference channels.
Further, the pilot mapping module is specifically configured to:
in the channel estimation stage of the network mode one, mapping a network mode one reference signal RS1 for uplink channel estimation on the selected symbols and resource elements; mapping a network mode one reference signal RS2 for the intermodulation interference channel estimation on the resource particles of the rest symbols, and simultaneously mapping a network mode two reference signal RS3 for the intermodulation interference channel estimation on the same symbol position on the aligned time slot corresponding to the network mode two; RS2 and RS3 simultaneously pass through a nonlinear system to generate an intermodulation process and a first intermodulation reference signal;
in the phase of network mode two channel estimation, mapping a network mode two reference signal RS4 used for uplink channel estimation on the selected symbols and resource elements; mapping network mode two reference signals RS5 for the intermodulation interference channel estimation on the resource particles of the rest symbols, and simultaneously mapping network mode one reference signal RS6 for the intermodulation interference channel estimation on the same symbol position on the corresponding aligned time slot of the network mode one; RS5 and RS6 simultaneously pass through the nonlinear system, generating an intermodulation process and a second intermodulation reference signal.
Further, the channel state information estimation module is specifically configured to:
in a channel estimation stage of a first network mode, columnar pilot frequency is inserted into a subframe in a time division multiplexing mode, meanwhile, columnar pilot frequency is inserted into a subframe of a second network mode in an auxiliary mode, channel state information CSI1 of an uplink channel of the first network mode is obtained based on RS1 estimation, channel state information CSI2 of the uplink channel of the second network mode is obtained based on RS3, and channel state information CSI3 of an intermodulation interference channel is obtained based on a first intermodulation reference signal;
in the channel estimation stage of the network mode two, the columnar pilot frequency is inserted into the subframe in a time division multiplexing mode, meanwhile, the columnar pilot frequency is inserted into the subframe of the network mode one in an auxiliary mode, channel state information CSI4 of an uplink channel of the network mode two is obtained based on RS4 estimation, channel state information CSI5 of the uplink channel of the network mode one is obtained based on RS6, and channel state information CSI6 of an intermodulation interference channel is obtained based on the second intermodulation reference signal.
Further, the estimation result optimization module is specifically configured to:
averaging the CSI3 and the CSI6 on each resource particle to realize frequency domain average filtering and obtain the channel state information of the optimized intermodulation interference channel;
averaging resource particles of CSI1 and CSI5 to realize frequency domain average filtering to obtain channel state information of an uplink channel of an optimized network mode I;
and averaging resource particles of the CSI2 and CSI4 to realize frequency domain average filtering, so as to obtain the channel state information of the uplink channel of the optimized network mode two.
Further, the method for estimating the channel state information of the intermodulation interference channel comprises:
performing discrete Fourier transform on the frequency domain information obtained by receiving and demodulating to obtain a first transform signal;
zeroing the first transformation signal to realize signal denoising and obtain a signal after the dryness removal;
and performing inverse Fourier transform twice on the signal after the dryness removal, and then performing time domain denoising operation on the signal after the inverse Fourier transform twice so as to complete the calculation of the channel state information of the intermodulation interference channel.
In yet another aspect, the present invention also provides an electronic device comprising a processor and a memory; wherein the memory has stored therein at least one instruction that is loaded and executed by the processor to implement the above-described method.
In yet another aspect, the present invention also provides a computer-readable storage medium having at least one instruction stored therein, the instruction being loaded and executed by a processor to implement the above method.
The technical scheme provided by the invention has the beneficial effects that at least:
1. the frame structure design provided by the invention can complete base station-terminal shared channel and self-interference channel estimation under the same frame resource, and avoids the change of the existing protocol and the requirement of extra frame resource.
2. The frame structure design provided by the invention multiplexes shared channel frame resources to carry out intermodulation self-interference channel estimation, can allocate time-frequency resources according to actual application, adjust OFDM symbols or time slots for reference signal transmission, adjust resource particle RE mapping, and better adapt to protocols and estimate channels.
3. The improved channel estimation algorithm provided by the invention can further enhance the estimation accuracy of the self-interference channel and the uplink channel and improve the accuracy deterioration problem caused by interference elimination due to signal-to-noise ratio and noise superposition factors.
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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 creative efforts.
FIG. 1 is a schematic diagram of a frame structure design provided by an embodiment of the present invention;
fig. 2 is a schematic flow chart of a channel estimation denoising calculation method according to an embodiment of the present invention;
fig. 3 is a schematic flowchart of an intermodulation CSI estimation method according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
First embodiment
The embodiment provides a full-duplex digital domain self-interference channel estimation method, which mainly aims at the potential interference problem in a multi-carrier system, and provides a frame structure design shown in figure 1 and an improved channel estimation method shown in figure 2 by taking the self-interference elimination idea and the multi-antenna port multiplexing idea of the full-duplex digital domain as reference; the frame structure design provided by the embodiment mainly aims at pilot frequency frame resources, and carries out multiplexing design on a mapping mode of a reference signal, so that possibility is provided for parallel channel estimation of an uplink channel and an intermodulation self-interference channel based on a multiplexing idea, and channel measurement of the uplink channel and the intermodulation interference channel of a terminal is realized; the improved channel estimation method is helpful for more accurately measuring and calculating the interference, thereby providing reference for interference elimination.
Based on the above, the core idea of the full-duplex digital domain self-interference channel estimation method of the embodiment is as follows:
1. the intermodulation interference elimination method of the embodiment is mainly used for multicarrier systems such as OFDM and the like;
2. the embodiment is inspired by the idea of full-duplex self-interference cancellation and the idea of time division multiplexing, a relevant frame structure and a channel estimation strategy are designed aiming at the potential intermodulation interference problem, a reference signal mapping mode and an interference channel estimation method are designed for interference cancellation, and a specific pilot frequency mode and a mapping method can be changed as required;
3. the frame structure design only aims at the data frame part of the reference signal, aims to utilize the existing protocol resource specification, constructs the reference signal to generate an intermodulation process in the terminal, and provides possibility for respectively estimating an uplink channel and a self-interference channel. The method comprises the steps that when uplink channel CSI is obtained, a local self-interference channel is estimated more accurately;
4. the improved channel estimation method provided by the embodiment combines a frequency domain denoising method and a transform domain denoising method on the basis of the original time domain denoising method to more accurately perform channel measurement, and the improved channel estimation method provided by the embodiment also has certain applicability to channel measurement with deteriorated signal-to-noise ratio and superimposed interference.
Specifically, referring to fig. 3, the full-duplex digital domain self-interference channel estimation method includes:
s1, allocating two adjacent time slot resources for the network mode I and the network mode II respectively; the resource blocks of the network mode I and the network mode II are respectively used for respective frequency band resources and are aligned in time;
s2, based on the allocated time slot resource, adopting time division multiplexing mode to complete the pilot frequency mapping of the reference signal;
specifically, the implementation process of the above steps includes:
s21, mapping network mode-one reference signal RS1 for uplink channel estimation on selected symbols (in slot) and resource elements, considering the first slot, i.e. the channel estimation stage of network mode one; because the reference signal does not fill all symbols of the whole time slot, by combining the time division and frequency division multiplexing ideas, a network mode one reference signal RS2 for intermodulation interference channel estimation is mapped on resource particles of the rest symbols, and meanwhile, a network mode two reference signal RS3 for intermodulation interference channel estimation is mapped on the same symbol position on an aligned time slot corresponding to the network mode two; RS2 and RS3 may simultaneously go through a nonlinear system to generate an intermodulation process and a first intermodulation reference signal for intermodulation interference channel estimation. The RS1 is used for uplink channel estimation and is staggered in time from the first intermodulation reference signal, so that interference is not caused to the first intermodulation reference signal.
S22, mapping network mode two reference signals RS4 for uplink channel estimation on selected symbols (in slots) and resource elements, considering the second slot, i.e. the network mode two channel estimation stage; the reference signals do not fill all symbols of the whole time slot, and by combining the time division and frequency division multiplexing ideas, network mode two reference signals RS5 for the intermodulation interference channel estimation are mapped on the resource elements of the rest symbols, and simultaneously, network mode one reference signals RS6 for the intermodulation interference channel estimation are mapped on the same symbol position on the corresponding aligned time slot of the network mode one; RS5 and RS6 may simultaneously go through a nonlinear system to generate an intermodulation process and a second intermodulation reference signal for use in intermodulation interference channel estimation. The RS4 is used for uplink channel estimation and is staggered in time from the second intermodulation reference signal, so that interference is not caused to the second intermodulation reference signal.
S3, channel state information estimation is respectively carried out in a network mode first stage and a network mode second stage based on the mapped reference signals, and channel state information of a plurality of uplink channels and intermodulation interference channels is obtained;
it should be noted that, when intermodulation interference exists inside the terminal, for the intermodulation interference channel, channel measurement needs to be performed by means of resource particles for the intermodulation channel. Since intermodulation interference involves aliasing of two signals, the present embodiment uses the time division multiplexing concept to make the two signals alias in the pilot subframe, and then uses the local transmit signal form and the local receive signal form of the terminal to estimate the channel state information of the self-interference channel.
Specifically, the implementation process of the above steps includes:
s31, inserting columnar pilot frequency in a subframe in a time division multiplexing mode in a channel estimation stage of a first network mode, and simultaneously assisting in inserting the columnar pilot frequency in a subframe of a second network mode, wherein pilot frequency mapping is performed in the time division multiplexing mode, so that channel state information CSI1 of an uplink channel of the first network mode can be theoretically obtained based on RS1 estimation, and channel state information CSI3 of an intermodulation interference channel is obtained based on a first intermodulation reference signal; and the reference signal for measuring the intermodulation interference channel is radiated to the base station by the antenna, so that the channel state information CSI2 of the uplink channel of the network mode two can be obtained based on the RS 3.
S32, in the channel estimation stage of the network mode II, inserting columnar pilot frequency in the subframe in a time division multiplexing mode, and simultaneously, assisting in inserting the columnar pilot frequency in the subframe of the network mode I, estimating and obtaining channel state information CSI4 of an uplink channel of the network mode II based on RS4, and obtaining channel state information CSI6 of an intermodulation interference channel based on a second intermodulation reference signal; and the reference signal for the intermodulation channel measurement is also radiated to the base station by the antenna, so the channel state information CSI5 of the uplink channel of the network mode one can be obtained based on the RS 6.
And S4, performing frequency domain mean filtering on the channel state information of the plurality of uplink channels and the intermodulation interference channels respectively to obtain the optimized channel state information of the uplink channels and the optimized channel state information of the intermodulation interference channels.
Specifically, the implementation process of the above steps includes:
averaging the CSI3 and the CSI6 on each resource particle to realize frequency domain average filtering so as to obtain more accurate optimized channel state information of the intermodulation interference channel; theoretically, the columnar pilot frequency is mainly used for simulating an intermodulation process in the terminal to calculate the channel state information of an intermodulation interference channel, and the columnar pilot frequency form is considered to avoid interpolation calculation and accurately provide self-interference information as much as possible.
In addition, in the whole process, the network mode I and the network mode II are equivalent to two times of reference signal transmission respectively, and theoretically, the base station side can respectively evaluate the respective channel states of the two network modes according to the two obtained reference signals so as to improve the estimation precision. Namely: averaging resource particles of CSI1 and CSI5 to realize frequency domain average filtering to obtain channel state information of an uplink channel of an optimized network mode I; and averaging resource particles of the CSI2 and CSI4 to realize frequency domain average filtering, so as to obtain the channel state information of the uplink channel of the optimized network mode two. Thereby preventing the noise superposition problem in the application of interference cancellation.
Furthermore, in consideration of the fact that channel measurement is carried out by adopting the thought of 'least square LS + time domain denoising' in actual communication, the LS algorithm is low in complexity but limited in precision, the thought of time domain denoising is to intercept the effective length of channel impulse response in the time domain and then carry out zero filling operation, and the effective part of the time domain is not further processed. Therefore, the present embodiment further improves the time domain denoising algorithm by combining the transform domain concept to suppress noise more effectively, and specifically, the improved channel estimation method of the present embodiment is shown in fig. 2 and includes:
performing Discrete Fourier Transform (DFT) on the frequency domain information obtained by receiving and demodulating to obtain a first transform signal; the algorithm principle selects an interception point M according to power, the interception point M is determined by the signal power of the initial M points and the last M points which are converted to be a certain percentage of the total signal power, after the frequency domain signals are subjected to DFT conversion again, useful signals are mainly distributed at 0 points and the end points of discrete signals, and noise is mainly distributed in the middle part;
zeroing the first transformation signal to realize signal denoising and obtain a signal after the dryness removal; the reason why the zero setting and drying operation is put before the time domain denoising is that the energy of the time domain signal is more concentrated and the occupation ratio of the useful signal is larger, if the time domain denoising operation is carried out firstly, the energy loss is caused, and the selection of the truncation point is not facilitated;
and performing inverse Fourier transform twice on the signal after the dryness removal, and then performing time domain denoising operation on the signal after the inverse Fourier transform twice so as to complete the calculation of the channel state information of the intermodulation interference channel.
In summary, in the present embodiment, for a multi-carrier system, under the existing protocol version, by means of the idea of time division multiplexing, an improvement is made on a mapping method and an estimation flow of a pilot time slot, and an antenna port mapping method is provided to perform self-interference channel and terminal uplink channel estimation in a time division multiplexing manner, so as to provide necessary information and possibility for self-interference cancellation, and theoretically, accurate measurement of a terminal uplink channel and an intermodulation interference channel CSI can be achieved. In addition, considering that interference cancellation relates to measurement of two different channels, which may relate to the problem of error superposition, and a self-interference channel estimation algorithm also directly relates to the accuracy of self-interference cancellation, therefore, this embodiment suppresses noise by means of a certain algorithm, and proposes an improved channel estimation strategy.
Second embodiment
The embodiment provides a full-duplex digital domain self-interference channel estimation system, which comprises the following modules:
the frame structure design module is used for respectively allocating two adjacent time slot resources for the network mode I and the network mode II; the resource blocks corresponding to the network mode I and the network mode II are respectively used for respective frequency band resources and are aligned in time;
the pilot frequency mapping module is used for finishing the pilot frequency mapping of the reference signal in a time division multiplexing mode based on the allocated time slot resources;
a channel state information estimation module, configured to perform channel state information estimation in a network mode first stage and a network mode second stage, respectively, based on the mapped reference signal, to obtain channel state information of a plurality of uplink channels and intermodulation interference channels;
and the estimation result optimization module is used for respectively carrying out frequency domain mean value filtering on the channel state information of the plurality of uplink channels and the intermodulation interference channels to obtain the optimized channel state information of the uplink channels and the optimized channel state information of the intermodulation interference channels.
The full-duplex digital domain self-interference channel estimation system of the present embodiment corresponds to the full-duplex digital domain self-interference channel estimation method of the first embodiment described above; the functions realized by the functional modules in the full-duplex digital domain self-interference channel estimation system of the present embodiment correspond to the flow steps in the full-duplex digital domain self-interference channel estimation method of the first embodiment one by one; therefore, it is not described herein.
Third embodiment
The present embodiment provides an electronic device, which includes a processor and a memory; wherein the memory has stored therein at least one instruction that is loaded and executed by the processor to implement the method of the first embodiment.
The electronic device may generate a large difference due to different configurations or performances, and may include one or more processors (CPUs) and one or more memories, where at least one instruction is stored in the memory, and the instruction is loaded by the processor and performs the following steps:
s1, allocating two adjacent time slot resources for the network mode I and the network mode II respectively; the resource blocks of the network mode I and the network mode II are respectively used for respective frequency band resources and are aligned in time;
s2, based on the allocated time slot resource, adopting time division multiplexing mode to complete the pilot frequency mapping of the reference signal;
s3, channel state information estimation is respectively carried out in a network mode first stage and a network mode second stage based on the mapped reference signals, and channel state information of a plurality of uplink channels and intermodulation interference channels is obtained;
and S4, performing frequency domain mean filtering on the channel state information of the plurality of uplink channels and the intermodulation interference channels respectively to obtain the optimized channel state information of the uplink channels and the optimized channel state information of the intermodulation interference channels.
Fourth embodiment
The present embodiments provide a computer-readable storage medium having at least one instruction stored therein, the instruction being loaded and executed by a processor to implement the above-mentioned method. The computer readable storage medium may be, among others, ROM, Random Access Memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device, and the like. The instructions stored therein may be loaded by a processor in the terminal and perform the steps of:
s1, allocating two adjacent time slot resources for the network mode I and the network mode II respectively; the resource blocks of the network mode I and the network mode II are respectively used for respective frequency band resources and are aligned in time;
s2, based on the allocated time slot resource, adopting time division multiplexing mode to complete the pilot frequency mapping of the reference signal;
s3, channel state information estimation is respectively carried out in a network mode first stage and a network mode second stage based on the mapped reference signals, and channel state information of a plurality of uplink channels and intermodulation interference channels is obtained;
and S4, performing frequency domain mean filtering on the channel state information of the plurality of uplink channels and the intermodulation interference channels respectively to obtain the optimized channel state information of the uplink channels and the optimized channel state information of the intermodulation interference channels.
Furthermore, it should be noted that the present invention may be provided as a method, apparatus or computer program product. Accordingly, embodiments of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present invention may take the form of a computer program product embodied on one or more computer-usable storage media having computer-usable program code embodied in the medium.
Embodiments of the present invention are described with reference to flowchart illustrations and/or block diagrams of methods, terminal devices (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, embedded processor, or other programmable data processing terminal to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal, 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 terminal 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 terminal to cause a series of operational steps to be performed on the computer or other programmable terminal to produce a computer implemented process such that the instructions which execute on the computer or other programmable terminal provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
It is further noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or terminal that comprises the element.
Finally, it should be noted that while the above describes a preferred embodiment of the invention, it will be appreciated by those skilled in the art that, once the basic inventive concepts have been learned, numerous changes and modifications may be made without departing from the principles of the invention, which shall be deemed to be within the scope of the invention. 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 embodiments of the invention.
Claims (8)
1. A full-duplex digital domain self-interference channel estimation method is characterized by comprising the following steps:
respectively allocating two adjacent time slot resources for the network mode I and the network mode II; the resource blocks corresponding to the network mode I and the network mode II are respectively used for respective frequency band resources and are aligned in time;
based on the allocated time slot resources, finishing pilot frequency mapping of the reference signals by adopting a time division multiplexing mode;
channel state information estimation is carried out on the basis of the mapped reference signals in a first network mode stage and a second network mode stage respectively to obtain channel state information of a plurality of uplink channels and intermodulation interference channels;
respectively carrying out frequency domain mean value filtering on the channel state information of a plurality of uplink channels and intermodulation interference channels to obtain optimized channel state information of the uplink channels and optimized channel state information of the intermodulation interference channels;
based on the allocated time slot resources, the pilot frequency mapping of the reference signal is completed in a time division multiplexing mode, and the method comprises the following steps:
in the channel estimation stage of the network mode one, mapping a network mode one reference signal RS1 for uplink channel estimation on the selected symbols and resource elements; mapping a network mode one reference signal RS2 for the intermodulation interference channel estimation on the resource particles of the rest symbols, and simultaneously mapping a network mode two reference signal RS3 for the intermodulation interference channel estimation on the same symbol position on the aligned time slot corresponding to the network mode two; RS2 and RS3 simultaneously pass through a nonlinear system to generate an intermodulation process and a first intermodulation reference signal;
in the phase of network mode two channel estimation, mapping a network mode two reference signal RS4 used for uplink channel estimation on the selected symbols and resource elements; mapping network mode two reference signals RS5 for the intermodulation interference channel estimation on the resource particles of the rest symbols, and simultaneously mapping network mode one reference signal RS6 for the intermodulation interference channel estimation on the same symbol position on the corresponding aligned time slot of the network mode one; RS5 and RS6 simultaneously pass through the nonlinear system, generating an intermodulation process and a second intermodulation reference signal.
2. The method of claim 1, wherein the channel state information estimation is performed in a first network mode stage and a second network mode stage based on the mapped reference signals, respectively, to obtain the channel state information of a plurality of uplink channels and intermodulation interference channels, comprising:
in a channel estimation stage of a first network mode, columnar pilot frequency is inserted into a subframe in a time division multiplexing mode, meanwhile, columnar pilot frequency is inserted into a subframe of a second network mode in an auxiliary mode, channel state information CSI1 of an uplink channel of the first network mode is obtained based on RS1 estimation, channel state information CSI2 of the uplink channel of the second network mode is obtained based on RS3, and channel state information CSI3 of an intermodulation interference channel is obtained based on a first intermodulation reference signal;
in the channel estimation stage of the network mode two, the columnar pilot frequency is inserted into the subframe in a time division multiplexing mode, meanwhile, the columnar pilot frequency is inserted into the subframe of the network mode one in an auxiliary mode, channel state information CSI4 of an uplink channel of the network mode two is obtained based on RS4 estimation, channel state information CSI5 of the uplink channel of the network mode one is obtained based on RS6, and channel state information CSI6 of an intermodulation interference channel is obtained based on the second intermodulation reference signal.
3. The method for estimating the full-duplex digital domain self-interference channel according to claim 2, wherein the step of performing frequency domain mean filtering on the channel state information of the plurality of uplink channels and the intermodulation interference channels respectively to obtain the channel state information of the optimized uplink channel and the channel state information of the optimized intermodulation interference channel comprises:
averaging the CSI3 and the CSI6 on each resource particle to realize frequency domain average filtering and obtain the channel state information of the optimized intermodulation interference channel;
averaging resource particles of CSI1 and CSI5 to realize frequency domain average filtering to obtain channel state information of an uplink channel of an optimized network mode I;
and averaging resource particles of the CSI2 and CSI4 to realize frequency domain average filtering, so as to obtain the channel state information of the uplink channel of the optimized network mode two.
4. The full-duplex digital domain self-interference channel estimation method of claim 1, wherein the estimation method of the channel state information of the intermodulation interference channel comprises:
performing discrete Fourier transform on the frequency domain information obtained by receiving and demodulating to obtain a first transform signal;
zeroing the first transformation signal to realize signal denoising and obtain a signal after the dryness removal;
and performing inverse Fourier transform twice on the signal after the dryness removal, and then performing time domain denoising operation on the signal after the inverse Fourier transform twice so as to complete the calculation of the channel state information of the intermodulation interference channel.
5. A full-duplex digital domain self-interference channel estimation system, comprising:
the frame structure design module is used for respectively allocating two adjacent time slot resources for the network mode I and the network mode II; the resource blocks corresponding to the network mode I and the network mode II are respectively used for respective frequency band resources and are aligned in time;
the pilot frequency mapping module is used for finishing the pilot frequency mapping of the reference signal in a time division multiplexing mode based on the allocated time slot resources;
a channel state information estimation module, configured to perform channel state information estimation in a network mode first stage and a network mode second stage, respectively, based on the mapped reference signal, to obtain channel state information of a plurality of uplink channels and intermodulation interference channels;
the estimation result optimization module is used for respectively carrying out frequency domain mean value filtering on the channel state information of the plurality of uplink channels and the intermodulation interference channels to obtain the channel state information of the optimized uplink channel and the channel state information of the optimized intermodulation interference channels;
based on the allocated time slot resources, the pilot frequency mapping of the reference signal is completed in a time division multiplexing mode, and the method comprises the following steps:
in the channel estimation stage of the network mode one, mapping a network mode one reference signal RS1 for uplink channel estimation on the selected symbols and resource elements; mapping a network mode one reference signal RS2 for the intermodulation interference channel estimation on the resource particles of the rest symbols, and simultaneously mapping a network mode two reference signal RS3 for the intermodulation interference channel estimation on the same symbol position on the aligned time slot corresponding to the network mode two; RS2 and RS3 simultaneously pass through a nonlinear system to generate an intermodulation process and a first intermodulation reference signal;
in the phase of network mode two channel estimation, mapping a network mode two reference signal RS4 used for uplink channel estimation on the selected symbols and resource elements; mapping network mode two reference signals RS5 for the intermodulation interference channel estimation on the resource particles of the rest symbols, and simultaneously mapping network mode one reference signal RS6 for the intermodulation interference channel estimation on the same symbol position on the corresponding aligned time slot of the network mode one; RS5 and RS6 simultaneously pass through the nonlinear system, generating an intermodulation process and a second intermodulation reference signal.
6. The full-duplex digital domain self-interference channel estimation system of claim 5, wherein the channel state information estimation module is specifically configured to:
in a channel estimation stage of a first network mode, columnar pilot frequency is inserted into a subframe in a time division multiplexing mode, meanwhile, columnar pilot frequency is inserted into a subframe of a second network mode in an auxiliary mode, channel state information CSI1 of an uplink channel of the first network mode is obtained based on RS1 estimation, channel state information CSI2 of the uplink channel of the second network mode is obtained based on RS3, and channel state information CSI3 of an intermodulation interference channel is obtained based on a first intermodulation reference signal;
in the channel estimation stage of the network mode two, the columnar pilot frequency is inserted into the subframe in a time division multiplexing mode, meanwhile, the columnar pilot frequency is inserted into the subframe of the network mode one in an auxiliary mode, channel state information CSI4 of an uplink channel of the network mode two is obtained based on RS4 estimation, channel state information CSI5 of the uplink channel of the network mode one is obtained based on RS6, and channel state information CSI6 of an intermodulation interference channel is obtained based on the second intermodulation reference signal.
7. The full-duplex digital domain self-interference channel estimation system of claim 6, wherein the estimation result optimization module is specifically configured to:
averaging the CSI3 and the CSI6 on each resource particle to realize frequency domain average filtering and obtain the channel state information of the optimized intermodulation interference channel;
averaging resource particles of CSI1 and CSI5 to realize frequency domain average filtering to obtain channel state information of an uplink channel of an optimized network mode I;
and averaging resource particles of the CSI2 and CSI4 to realize frequency domain average filtering, so as to obtain the channel state information of the uplink channel of the optimized network mode two.
8. The full-duplex digital domain self-interference channel estimation system of claim 5, wherein the method of estimating the channel state information of the intermodulation interference channel comprises:
performing discrete Fourier transform on the frequency domain information obtained by receiving and demodulating to obtain a first transform signal;
zeroing the first transformation signal to realize signal denoising and obtain a signal after the dryness removal;
and performing inverse Fourier transform twice on the signal after the dryness removal, and then performing time domain denoising operation on the signal after the inverse Fourier transform twice so as to complete the calculation of the channel state information of the intermodulation interference channel.
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| CN101924610A (en) * | 2010-08-02 | 2010-12-22 | 西安电子科技大学 | Method for designing channel state information reference signal (CSI-RS) in LTE-A (Long Term Evolution-Advanced) system |
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