CN111447162B - Transmission method and system in long-term evolution communication system - Google Patents

Transmission method and system in long-term evolution communication system Download PDF

Info

Publication number
CN111447162B
CN111447162B CN201910042680.6A CN201910042680A CN111447162B CN 111447162 B CN111447162 B CN 111447162B CN 201910042680 A CN201910042680 A CN 201910042680A CN 111447162 B CN111447162 B CN 111447162B
Authority
CN
China
Prior art keywords
subframe
signal
symbol
cyclic prefix
ofdm symbol
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201910042680.6A
Other languages
Chinese (zh)
Other versions
CN111447162A (en
Inventor
张东磊
李建岐
安春燕
陆阳
郑伟军
邵炜平
方景辉
钱伟杰
刘维亮
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
State Grid Corp of China SGCC
State Grid Zhejiang Electric Power Co Ltd
Global Energy Interconnection Research Institute
Jiaxing Power Supply Co of State Grid Zhejiang Electric Power Co Ltd
Original Assignee
State Grid Corp of China SGCC
State Grid Zhejiang Electric Power Co Ltd
Global Energy Interconnection Research Institute
Jiaxing Power Supply Co of State Grid Zhejiang Electric Power Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by State Grid Corp of China SGCC, State Grid Zhejiang Electric Power Co Ltd, Global Energy Interconnection Research Institute, Jiaxing Power Supply Co of State Grid Zhejiang Electric Power Co Ltd filed Critical State Grid Corp of China SGCC
Priority to CN201910042680.6A priority Critical patent/CN111447162B/en
Publication of CN111447162A publication Critical patent/CN111447162A/en
Application granted granted Critical
Publication of CN111447162B publication Critical patent/CN111447162B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2668—Details of algorithms
    • H04L27/2681—Details of algorithms characterised by constraints
    • H04L27/2688—Resistance to perturbation, e.g. noise, interference or fading
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2626—Arrangements specific to the transmitter only
    • H04L27/2627—Modulators
    • H04L27/2628—Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2668—Details of algorithms
    • H04L27/2673—Details of algorithms characterised by synchronisation parameters
    • H04L27/2676—Blind, i.e. without using known symbols
    • H04L27/2678—Blind, i.e. without using known symbols using cyclostationarities, e.g. cyclic prefix or postfix
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2689—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation
    • H04L27/2691—Link with other circuits, i.e. special connections between synchronisation arrangements and other circuits for achieving synchronisation involving interference determination or cancellation

Abstract

The invention provides a transmission method and a system in a long-term evolution communication system, comprising the following steps: receiving signals by adopting a preprocessed physical channel; performing channel estimation on each subframe in the signal and a first Orthogonal Frequency Division Multiplexing (OFDM) symbol of a next subframe of the subframe, eliminating interference among remaining OFDM symbols in the subframe, and obtaining the remaining OFDM symbols in the subframe; obtaining a final signal based on a first OFDM symbol of the subframe and the rest OFDM symbols in the subframe; wherein the signal comprises: the sub-frames are composed of a first part and a second part, the first part is the first OFDM symbol with the reserved cyclic prefix, and the second part is 6 OFDM symbols with the cyclic prefix removed. The invention adopts shorter frame length on the premise of ensuring backward compatibility, and realizes overhead reduction by removing cyclic prefix, thereby finally achieving the purpose of reducing air interface time delay.

Description

Transmission method and system in long-term evolution communication system
Technical Field
The present invention relates to the field of long term evolution communication systems, and in particular, to a transmission method and system in a long term evolution communication system.
Background
The development of mobile wireless communication technology is one of the main motivations for promoting the information process of the world at present, and just because of the development of the mobile wireless communication technology, people overcome the obstacle of space communication, and basically realize the desire of communication anytime and anywhere. With the continuous progress of informatization, the requirements of people on the data experience rate, the call quality, the system capacity and the like of communication are higher and higher, and due to the increasing demands, the further development of the communication technology is promoted.
Higher data rates, faster network access speeds and lower data delays compared to 3G are significant advantages of LTE over previous generation mobile radio technologies. As an Evolution project of the 3G, long Term Evolution (LTE) improves and enhances an air access technology of the 3G, and adopts an Orthogonal Frequency Division Multiplexing (OFDM) technology and a Multiple-Input Multiple-Output (MIMO) technology as a standard of wireless network Evolution, so that an access service larger than l00kbps can be provided for a 350km/h high-speed mobile user, a unidirectional transmission delay in a user plane is lower than 5ms, a transition time of a control plane from a sleep state to an active state is lower than 50ms, a transition time of a control plane from the sleep state to the active state is lower than l00ms, a system delay, especially an air interface delay, is an important index for promoting LTE design and development.
In the third Generation Partnership project (3 gpp) protocol, from Release 8 to Release 12 of LTE, there have been proposed techniques such as Carrier Aggregation, CA, 8xg mimo,256 Quadrature Amplitude Modulation (QAM), and the like, and the data rate of the L1 layer has been increased from 300Mbps to 4Gbps. In Release 13, 3GPP further improves the bit rate of data by introducing 32 subcarriers in carrier aggregation, however, little progress has been made in reducing the system transmission delay, especially in shortening the Transmission Time Interval (TTI). Although various pre-scheduling strategies can reduce the delay to a certain extent, the method for shortening the scheduling request interval introduced in Release 9 does not give good consideration to the efficiency problem, and the existing LTE system has reduced the TTI to lms. Compared with the research on the aspects of data rate of a communication system and the like, the work progress of reducing the transmission delay by optimizing the TTI is very slow, and considering that the reduction of the transmission delay has important significance for accelerating the system response, improving the average throughput and the like, the TTI is an important component of the system transmission delay, how to reduce the system transmission delay and improve the system performance is worth researching.
Disclosure of Invention
In order to solve the problem that the transmission delay is not reduced by optimizing TTI in the prior art, the invention provides a transmission method and a transmission system in a long term evolution communication system.
The technical scheme provided by the invention is as follows: a method of transmission in a long term evolution communication system, comprising:
receiving signals by adopting a preprocessed physical channel;
performing channel estimation on each subframe in the signal and a first Orthogonal Frequency Division Multiplexing (OFDM) symbol of a next subframe of the subframe, eliminating interference among remaining OFDM symbols in the subframe, and obtaining the remaining OFDM symbols in the subframe;
obtaining a final signal based on a first OFDM symbol of the subframe and the rest OFDM symbols in the subframe;
wherein the signal comprises: the OFDM signal transmission method comprises subframes composed of 7 OFDM symbols, wherein each subframe is composed of a first part and a second part, the first part is a first OFDM symbol with a reserved cyclic prefix, and the second part is 6 OFDM symbols with the removed cyclic prefix.
Preferably, the performing channel estimation on the first OFDM symbol of each subframe in the signal and the subframe next to the subframe to eliminate interference between remaining OFDM symbols in the subframe and obtain the remaining OFDM symbols in the subframe includes:
obtaining time domain channel impulse response of a first OFDM symbol in a subframe based on channel frequency response of channel estimation;
extracting taps from the time-domain channel impulse response based on threshold detection;
acquiring intersymbol interference of the first part to the second part in the subframe based on the taps;
obtaining a second part signal for eliminating the intersymbol interference based on the intersymbol interference of the first part to the second part;
obtaining an inter-symbol interference component based on a cyclic prefix of a first OFDM symbol in a next transmission time interval;
replacing the first portion to second portion inter-carrier interference based on the inter-symbol interference component;
and obtaining a signal of the second part based on the second part signal for eliminating the intersymbol interference and the intersymbol interference component.
Preferably, the time-domain channel impulse response of the first OFDM symbol is calculated as follows:
Figure GDA0003781278380000031
in the formula: h [ n ]]: a time domain channel impulse response; n is a radical of taps : the number of taps; a is j : complex amplitude of tap j times; n: a time index; tau is j : the delay associated with j taps.
Preferably, the intersymbol interference of the first portion to the second portion is represented by the following formula:
Figure GDA0003781278380000032
in the formula: ISI: intersymbol interference of the first portion with the second portion;
Figure GDA0003781278380000033
a time domain transmit signal of a first OFDM symbol in the first portion that does not include a cyclic prefix; n is a radical of hydrogen OFDM : removing the OFDM symbol length after the cyclic prefix; tau is max : a maximum value of a channel delay;
preferably, the second partial signal for canceling intersymbol interference is represented by the following formula:
Figure GDA0003781278380000034
in the formula:
Figure GDA0003781278380000035
a second part signal for eliminating intersymbol interference;
Figure GDA0003781278380000036
a first OFDM symbol in the first portion that does not include a cyclic prefix;
Figure GDA0003781278380000037
the remaining 6 OFDM symbols in the second part.
Preferably, the intersymbol interference component is described by the following equation:
Figure GDA0003781278380000038
in the formula: ISI (inter-symbol interference) TTI+1 [n]: an intersymbol interference component;
Figure GDA0003781278380000039
a first OFDM symbol in a first portion of a next transmission time interval that does not include a cyclic prefix; n' taps : the number of taps of the first OFDM symbol in the next transmission time interval; a' j : complex amplitude of j taps of the first OFDM symbol in the next transmission time interval; tau' j : the delay associated with j taps for the first OFDM symbol in the next transmission time interval;
Figure GDA0003781278380000041
transmitting a signal in the time domain of a first OFDM symbol not including a cyclic prefix in a first part of a next transmission time interval; n is a radical of hydrogen OFDM : removing the OFDM symbol length after the cyclic prefix; n: a time index; n is a radical of CP : the length of the cyclic prefix.
Preferably, the signal of the second part is represented by the following formula:
Figure GDA0003781278380000042
n＝0,...,6N OFDM -1
in the formula:
Figure GDA0003781278380000043
a second portion of the signal;
Figure GDA0003781278380000044
and eliminating the second part signal of the intersymbol interference.
Preferably, the transmission method in the long term evolution communication system further includes:
generating control information and information blocks to be transmitted into signals consisting of subframes;
and transmitting the signal based on the preprocessed physical channel.
Preferably, the generating a signal composed of subframes from the control information and the information block to be transmitted includes:
mapping the control information to subcarriers to generate frequency domain components of a first OFDM symbol;
after the frequency domain component of the first OFDM symbol passes through an Inverse Fast Fourier Transform (IFFT), inserting a cyclic prefix to obtain a first part of the subframe;
adding protection to the information block through Forward Error Correction (FEC) coding;
obtaining an information target block based on the interleaver compensating the frequency diversity loss in the information block;
obtaining a second part of the subframe for the information target block based on subcarrier mapping and Inverse Fast Fourier Transform (IFFT);
and cascading the first part and the second part to generate a signal consisting of a subframe.
Preferably, the pre-processed physical channel includes:
and the physical channel is composed based on a Physical Uplink Control Channel (PUCCH) and an enhanced downlink physical control channel (EPDCCH).
Preferably, the signal further comprises: a sub-frame consisting of 14 OFDM symbols, wherein all 14 OFDM symbols in the sub-frame contain cyclic prefixes.
Preferably, after receiving the signal by using the pre-processed physical channel, before obtaining a final signal based on the first OFDM symbol of the subframe and the remaining OFDM symbols in the subframe, the method further includes:
detecting each sub-frame in the signal, when the number of the cyclic prefixes in the sub-frames is 1,
performing channel estimation on the subframe and a first Orthogonal Frequency Division Multiplexing (OFDM) symbol of a subframe next to the subframe, eliminating interference among remaining OFDM symbols in the subframe, and obtaining the remaining OFDM symbols in the subframe;
otherwise, the final signal is obtained based on 14 OFDM symbols.
Based on the same inventive concept, the invention also provides a transmission system in a long term evolution communication system, comprising:
the receiving module is used for receiving signals by adopting a preprocessed physical channel;
an interference elimination module, configured to perform channel estimation on each subframe in the signal and a first OFDM symbol of a subframe next to the subframe, eliminate interference between remaining OFDM symbols in the subframe, and obtain remaining OFDM symbols in the subframe;
a result module, configured to obtain a final signal based on a first OFDM symbol of the subframe and remaining OFDM symbols in the subframe;
wherein the signal comprises: the sub-frames are composed of a first part and a second part, the first part is the first OFDM symbol with the reserved cyclic prefix, and the second part is 6 OFDM symbols with the cyclic prefix removed.
Preferably, the interference elimination module includes:
the obtaining time domain channel impulse response unit is used for obtaining the time domain channel impulse response of the first OFDM symbol in the subframe based on the channel frequency response of the channel estimation;
an extraction tap unit for extracting a tap from the time domain channel impulse response based on threshold detection;
an inter-symbol interference unit for obtaining inter-symbol interference of the first part to the second part in the subframe based on the tap;
an inter-symbol interference elimination unit, configured to obtain a second partial signal with inter-symbol interference eliminated based on inter-symbol interference of the first partial to the second partial;
an inter-symbol interference component obtaining unit, configured to obtain an inter-symbol interference component based on a cyclic prefix of a first OFDM symbol in a next transmission time interval;
a replace inter-carrier interference unit to replace inter-carrier interference of the first portion to the second portion based on the inter-symbol interference component;
and a second partial signal unit for obtaining a second partial signal based on the second partial signal for canceling the intersymbol interference and the intersymbol interference component.
Based on the same inventive concept, the invention also provides a transmission method in the long-term evolution communication system, which comprises the following steps:
mapping control information to be sent on the basis of subcarriers and inserting cyclic prefixes to obtain a first part;
adding protection to an information block to be transmitted based on Forward Error Correction (FEC) coding, and compensating frequency diversity loss in the information block through an interleaver to obtain a second part;
transmitting signals generated by cascading the first part and the second part based on a preprocessed physical channel;
the first part is the first OFDM symbol with the cyclic prefix reserved, and the second part is the 6 OFDM symbols with the cyclic prefix removed.
Preferably, the obtaining the first part based on subcarrier mapping and cyclic prefix insertion for the control information to be sent includes:
mapping the control information to subcarriers to generate frequency domain components of a first OFDM symbol;
and after the frequency domain component of the first OFDM symbol passes through an Inverse Fast Fourier Transform (IFFT), inserting a cyclic prefix to obtain a first part of the subframe.
Preferably, the adding protection to the information block to be transmitted based on forward error correction FEC coding and the obtaining the second part by compensating for the frequency diversity loss in the information block through an interleaver include:
adding protection to the information block through Forward Error Correction (FEC) coding;
obtaining an information target block based on the interleaver compensating the frequency diversity loss in the information block;
and obtaining a second part of the subframe for the information target block based on subcarrier mapping and Inverse Fast Fourier Transform (IFFT).
Preferably, the pre-processed physical channel includes:
and the physical channel is composed of a Physical Uplink Control Channel (PUCCH) and an enhanced downlink physical control channel (EPDCCH).
Based on the same inventive concept, the invention provides a transmission system in a long term evolution communication system, comprising:
a first generating module, configured to map and insert a cyclic prefix into control information to be sent based on a subcarrier to obtain a first part;
a second generating module, configured to add protection to an information block to be sent based on forward error correction FEC coding, and obtain a second part by compensating for frequency diversity loss in the information block through an interleaver;
a transmitting module, configured to transmit a signal generated by cascading the first part and the second part based on a pre-processed physical channel;
the first part is the first OFDM symbol with the cyclic prefix reserved, and the second part is the 6 OFDM symbols with the cyclic prefix removed.
Preferably, the first generating module includes:
a frequency domain component generating unit, configured to map the control information to subcarriers to generate frequency domain components of a first OFDM symbol;
and a first part obtaining unit, configured to insert a cyclic prefix after the frequency domain component of the first OFDM symbol is subjected to Inverse Fast Fourier Transform (IFFT), to obtain a first part of the subframe.
Compared with the prior art, the invention has the following beneficial effects:
the technical scheme provided by the invention adopts a preprocessed physical channel to receive signals; performing channel estimation on each subframe in the signal and a first Orthogonal Frequency Division Multiplexing (OFDM) symbol of a next subframe of the subframe, eliminating interference among remaining OFDM symbols in the subframe, and obtaining the remaining OFDM symbols in the subframe; obtaining a final signal based on a first OFDM symbol of the subframe and the rest OFDM symbols in the subframe; wherein the signal comprises: the invention optimizes the sub-frame by removing the cyclic prefix, adopts shorter frame length when ensuring backward compatibility, reduces the transmission delay of the system and achieves the purpose of reducing the time delay of an air interface.
The technical scheme provided by the invention reduces 14 OFDM symbols into 7 OFDM symbols, reduces the cost of the original cyclic prefix and reduces the time delay of an air interface.
Drawings
Fig. 1 is a flow chart of a transmission method provided by the present invention;
FIG. 2 is a diagram illustrating a first sub-frame structure according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of frequency reuse of a first subframe and a second subframe according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of system scheduling of a first subframe and a second subframe according to an embodiment of the present invention;
FIG. 5 is a diagram illustrating a first subframe with CP removed according to an embodiment of the present invention;
fig. 6 is a block diagram of a transmitter transmitting a first subframe in an embodiment of the present invention.
Detailed Description
For a better understanding of the present invention, reference is made to the following description taken in conjunction with the accompanying drawings and examples.
Example 1:
as shown in fig. 1, a transmission method in a long term evolution communication system includes:
s1, receiving a signal by adopting a preprocessed physical channel;
s2, performing channel estimation on each subframe in the signal and a first Orthogonal Frequency Division Multiplexing (OFDM) symbol of a subframe next to the subframe, eliminating interference among remaining OFDM symbols in the subframe, and obtaining the remaining OFDM symbols in the subframe;
s3, obtaining a final signal based on the first OFDM symbol of the subframe and the rest OFDM symbols in the subframe;
wherein the signal comprises: the OFDM signal transmission method comprises subframes composed of 7 OFDM symbols, wherein each subframe is composed of a first part and a second part, the first part is a first OFDM symbol with a reserved cyclic prefix, and the second part is 6 OFDM symbols with the removed cyclic prefix.
In this embodiment, a slot including 7 OFDM symbols is referred to as a first subframe, where the 7 OFDM symbols are composed of a first part and a second part, the first part is a first OFDM symbol in which a cyclic prefix CP is reserved, and the second part is 6 OFDM symbols in which the cyclic prefix CP is removed in a time transmission interval;
two slots containing 14 OFDM symbols are referred to as a second subframe.
The technical scheme provided by the invention reduces 14 OFDM symbols to 7 OFDM symbols aiming at the requirement of low time delay, and reduces the expense of the original cyclic prefix to form a first subframe, thereby reducing the time delay of an air interface.
The process of reducing 14 OFDM symbols to 7 OFDM symbols in this embodiment includes the following steps:
the largest time unit is a 10ms radio frame, divided into 10 1ms subframes, each divided into two 0.5ms slots, each slot consisting of 7 OFDM symbols for the normal cyclic prefix length. Dividing a subframe containing 14 OFDM symbols into two parts, taking each time slot as an optimized subframe in a time domain, namely a first subframe, and containing 7 OFDM symbols; the subframe containing 14 OFDM symbols is a legacy subframe, i.e., a second subframe.
When transmitting a signal: scheduling a first subframe or a second subframe based on the load capacity of each region to be transmitted, and realizing frequency multiplexing of the first subframe or the second subframe through evolved node scheduling, wherein the method comprises the following steps:
the eNodeB can determine whether to call the traditional LTE subframe or the optimized LTE subframe currently according to the information such as the cell load, namely the cell load is small, the channel condition is good, and the optimized LTE subframe can be called to improve the system delay and the throughput performance; otherwise, the cell load is large, the channel condition is poor, and the reliability should be ensured by calling the conventional LTE subframe. The frequency multiplexing of the traditional sub-frame and the optimized sub-frame is realized on the same carrier wave through the scheduling of an eNodeB (Evolved Node B) to ensure the backward compatibility.
Transmitting a transmission signal composed of the first subframe and the second subframe based on a preprocessed physical channel, wherein the method comprises the following steps:
in consideration of backward compatibility and reduction of an influence on a conventional User Experience (UE), a structure of a Physical Downlink Control Channel (PDCCH) is not improved, but in a conventional LTE system, the PDCCH occupies the entire system bandwidth, and an Enhanced Physical Downlink Control Channel (EPDCCH) only occupies a configured Physical Resource Block (PRB).
Therefore, in this embodiment, EPDCCH is used to implement downlink scheduling of the optimized system, and further, multiplexing of two subframes is implemented in the frequency domain.
The present invention proposes to achieve significant overhead reduction by retaining only the cyclic prefix corresponding to the first OFDM symbol and removing the remaining prefixes in the time transmission interval, specifically including:
the time domain samples of the first OFDM symbol are obtained by applying an Inverse discrete Fourier Transform (IFFT) algorithm to complex sub-carriers carrying information and pilot, as in LTE. However, the remainder of the TTI is obtained by a longer IFFT of the concatenated subcarrier sets corresponding to the remaining 6 original OFDM symbols.
Step S2, channel estimation is carried out on each subframe in the signal and the first OFDM symbol of the next subframe of the subframe, interference among the rest OFDM symbols in the subframe is eliminated, and the rest OFDM symbols in the subframe are obtained, wherein the channel estimation comprises the following steps:
the main advantage of the TTI structure proposed in the present invention is that it can more effectively handle Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI) without affecting the maximum supported Carrier Frequency Offset (CFO) determined by the first OFDM Symbol.
Furthermore, ISI and ICI cancellation algorithms rely only on channel estimates at the first OFDM symbol, thus improving reliability due to the preserved CP.
Since there is a higher number of subcarriers in the second part of the TTI resulting in lower frequency diversity, adjacent subcarriers will experience lower channel variation in the frequency domain, thereby affecting Forward Error Correction (FEC) decoding. To compensate for this undesirable effect, the present invention proposes to achieve an effective increase in frequency diversity at reception by adding an interleaver after FEC coding.
The present invention proposes an algorithm at the receiver for eliminating any inter-symbol and inter-carrier interference present in the multipath channel:
the time-domain Channel Impulse Response (CIR) at the first OFDM symbol, which typically includes a delay discrete delta function representing the multipath components (taps) of multiple radio channels, may first be obtained by an IFFT of the estimated channel frequency response.
The receiver can extract the most important taps from the CIR by threshold detection, resulting in the following expression:
Figure GDA0003781278380000101
in the formula: n is a radical of taps Is the number of taps, a j Is the complex amplitude of the j taps, τ j Is the delay associated with the j taps.
The time-domain ISI term that affects the second part of the TTI can then be written in the form:
Figure GDA0003781278380000102
where n is the time index, τ max Is the maximum value of the channel delay, N OFDM Refers to the OFDM symbol length after CP removal,
Figure GDA0003781278380000103
which represents the time domain transmitted signal of the first OFDM symbol (excluding the cyclic prefix), wherein,
Figure GDA0003781278380000104
where g is the calculated value.
Since ideally the second part is free from inter-symbol interference from the first OFDM symbol, the ISI component can be subtracted from it,
Figure GDA0003781278380000111
wherein, the first and the second end of the pipe are connected with each other,
Figure GDA0003781278380000112
refers to the first OFDM symbol (excluding CP),
Figure GDA0003781278380000113
the remaining 6 OFDM symbols are referred to.
Before frequency domain equalization, the periodicity of the signal must also be restored, i.e., ICI is cancelled, and cyclic shift does not occur in the delayed replica of the signal due to the effect of multipath components. Then after being affected by the complex amplitude and delay of the multipath components, OFDM samples "missing" on the right side of the TTI should be introduced to the left side as in the cyclic shift register. Although the samples to be reconstructed are in principle unknown, they can be found in the first OFDM symbol towards the next TTI in the form of ISI, and thus the ISI component can be replaced by the obtained ISI component by obtaining it from the cyclic prefix of the first symbol in the next TTI.
By using
Figure GDA0003781278380000114
A received signal representing the first symbol in the next TTI,
Figure GDA0003781278380000115
wherein ISI TTI+1 [n]Indicating an ISI component extending towards the first OFDM symbol of the next TTI; n' taps ，a′ j ，τ′ j The channel tap components in the first OFDM symbol of the next TTI are represented, and at the same time,
Figure GDA0003781278380000116
wherein h is the calculated value.
The second part of the TTI after the ISI and ICI components are removed may be expressed as:
Figure GDA0003781278380000117
wherein n =0, \8230;, 6N_OFDM-1
This process requires the receiver to additionally decode the first OFDM symbol of the next TTI before decoding the current TTI. After ISI and ICI cancellation, detection in the second part of the TTI is preceded by a fast fourier transform of length 6n _ofdm, followed by channel estimation and equalization. It is assumed that the channel frequency response remains valid over the entire second part of the TTI, i.e. the channel coherence time is larger than the duration of the second part of the TTI. This assumption is reasonable in order to achieve significant delay reduction when the symbol length is reduced.
Example 2:
as shown in fig. 2, for the first sub-frame, i.e. the sub-frame structure after optimization, the maximum time unit is a 10ms radio frame, which is divided into 10 sub-frames of 1ms, each sub-frame is divided into two slots of 0.5ms, and for the normal cyclic prefix length, each slot is composed of 7 OFDM symbols. A subframe containing 14 OFDM symbols is divided into two parts, and each time slot is taken as an optimized subframe containing 7 OFDM symbols in a time domain.
As shown in fig. 3, the frequency reuse graph of the first subframe and the second subframe, that is, the conventional subframe and the optimized subframe, realizes frequency reuse of the conventional subframe and the optimized subframe on the same carrier by scheduling of the eNodeB, and ensures backward compatibility. For a UE supporting multiple subframe modes, an optimized LTE subframe may be called through Radio Resource Control (RRC) signaling. In the LTE system, the PDCCH carries scheduling of a specific UE and Downlink Control Information (DCI) including downlink resource allocation, uplink/downlink power control commands, and the like, and thus resource allocation can be obtained by carrying the DCI through the PDCCH. The eNodeB may decide whether to currently invoke the conventional LTE subframe or the optimized LTE subframe according to information such as cell load.
As shown in fig. 4, a system scheduling diagram is shown, in which the structure of the PDCCH is not improved in consideration of backward compatibility and reduction of the impact on legacy UEs. In the conventional LTE system, the PDCCH occupies the entire system bandwidth, and the EPDCCH only occupies the configured Physical Resource Block (PRB). Therefore, the downlink scheduling of the optimized system can be realized by using the EPDCCH, and the multiplexing of two subframes is further realized on the frequency domain. In the downlink, a subframe with a duration of 1ms is divided into two subframes with a duration of 0.5 ms. A conventional UE may implement scheduling of a Physical Downlink Shared Channel (PDSCH) through a PDCCH and an EPDCCH.
The first optimized subframe can still use the conventional PDCCH to schedule a shortened physical downlink shared channel (sPDSCH), while in the second optimized subframe, since the PDCCH occupies the entire system bandwidth, it is impossible to reuse the PDCCH to schedule the sPDSCH. The sPDSCH may be scheduled by means of a shortened enhanced physical downlink control channel (epdcch). The EPDCCH, which is shortened in duration in the time domain, requires more resource blocks in the frequency domain compared to the conventional EPDCCH. And for constituent units of EPDCCH: a shortened enhanced resource group (sleeg) and a shortened enhanced control channel particle (sECCE) corresponding to the enhanced resource group (EREG) and the enhanced control channel particle (ECCE) are also redefined.
As shown in fig. 5, for the TTI diagram after the CP is removed from the first subframe, the time domain samples of the first OFDM symbol are obtained by IFFT using complex subcarriers carrying information and pilot, as in LTE. However, the second part of the TTI is obtained by a longer IFFT of the concatenated subcarrier sets corresponding to the remaining 6 original OFDM symbols.
The main advantage of the proposed TTI is to handle ISI and ICI more efficiently without affecting the maximum supported Carrier Frequency Offset (CFO) determined for the first OFDM symbol. Furthermore, ISI and ICI cancellation algorithms rely only on proper channel estimation at the first OFDM symbol, thus improving reliability due to the preserved CP. In order to perform channel estimation on the second part of the TTI, the pilot subcarriers must be arranged to cover the system bandwidth with increased frequency resolution given by the enlarged symbol length, but the spacing between pilot subcarriers in the frequency domain should be increased compared to the first symbol, with more data subcarriers between each pair of pilot subcarriers. However, the channel estimation accuracy is not affected because the channel coherence bandwidth also extends to 6 times the subcarriers in the first OFDM symbol, resulting in the same channel estimation capability.
As shown in fig. 6, a block diagram of a first subframe is transmitted for a transmitter. Since there is a higher number of subcarriers in the second part of the TTI resulting in lower frequency diversity, adjacent subcarriers will experience lower channel variation in the frequency domain, thereby affecting Forward Error Correction (FEC) decoding. To compensate for this undesirable effect, frequency diversity can be effectively increased upon reception by adding an interleaver after FEC coding.
The method comprises the following steps: acquiring a first part and acquiring a second part;
a first portion acquisition comprising: firstly, generating control information and mapping the control information to subcarriers through a first subcarrier mapping block so as to generate frequency domain components of a first OFDM symbol, and then obtaining the first OFDM symbol through IFFT and CP addition processing;
obtaining a second part, wherein the information block is firstly protected by an FEC coding block, and then an interleaver compensates the frequency diversity loss introduced by the amplified IFFT in the second part to obtain an information target block;
then mapping the sub-carriers to time-frequency resources through a second sub-carrier mapping block, wherein the sub-carriers comprise pilot frequency sub-carriers used for channel estimation;
then, IFFT sampling is carried out to convert the time domain into a time domain;
finally, the two parts are concatenated to generate a first subframe.
Example 3
Based on the same inventive concept, the invention also provides a transmission system in a long term evolution communication system, which comprises:
the receiving module is used for receiving signals by adopting a preprocessed physical channel;
an interference elimination module, configured to perform channel estimation on each subframe in the signal and a first OFDM symbol of a subframe next to the subframe, eliminate interference between remaining OFDM symbols in the subframe, and obtain remaining OFDM symbols in the subframe;
a result module, configured to obtain a final signal based on a first OFDM symbol of the subframe and remaining OFDM symbols in the subframe;
wherein the signal comprises: the sub-frames are composed of a first part and a second part, the first part is the first OFDM symbol with the reserved cyclic prefix, and the second part is 6 OFDM symbols with the cyclic prefix removed.
In an embodiment, the interference cancellation module includes:
the obtaining time domain channel impulse response unit is used for obtaining the time domain channel impulse response of the first OFDM symbol in the subframe based on the channel frequency response of the channel estimation;
an extraction tap unit for extracting a tap from the time domain channel impulse response based on threshold detection;
an inter-symbol interference unit for obtaining inter-symbol interference of the first part to the second part in the subframe based on the tap;
an inter-symbol interference elimination unit, configured to obtain a second partial signal with inter-symbol interference eliminated based on inter-symbol interference of the first partial to the second partial;
an inter-symbol interference component obtaining unit, configured to obtain an inter-symbol interference component based on a cyclic prefix of a first OFDM symbol in a next transmission time interval;
a replace inter-carrier interference unit to replace inter-carrier interference of the first portion to the second portion based on the inter-symbol interference component;
and a second partial signal unit for obtaining a second partial signal based on the second partial signal for canceling the intersymbol interference and the intersymbol interference component.
Based on the same inventive concept, the invention also provides a transmission system in a long term evolution communication system, comprising:
a first generating module, configured to map and insert a cyclic prefix into control information to be sent based on subcarriers to obtain a first part;
a second generating module, configured to add protection to an information block to be sent based on forward error correction, FEC, coding, and obtain a second part by compensating, by an interleaver, a frequency diversity loss in the information block;
a transmitting module, configured to transmit a signal generated by cascading the first part and the second part based on a pre-processed physical channel;
the first part is the first OFDM symbol with the cyclic prefix reserved, and the second part is 6 OFDM symbols with the cyclic prefix removed.
In an embodiment, the first generating module includes:
a frequency domain component generating unit, configured to map the control information to subcarriers to generate frequency domain components of a first OFDM symbol;
and the first part obtaining unit is used for inserting a cyclic prefix after the frequency domain component of the first OFDM symbol passes through IFFT (inverse fast Fourier transform), so as to obtain the first part of the subframe.
It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The present invention is not limited to the above embodiments, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are included in the scope of the claims of the present invention which are filed as the application.

Claims (16)

1. A method for transmission in a long term evolution communication system, comprising:
receiving signals by adopting a preprocessed physical channel;
performing channel estimation on each subframe in the signal and a first Orthogonal Frequency Division Multiplexing (OFDM) symbol of a next subframe of the subframe, eliminating interference among remaining OFDM symbols in the subframe, and obtaining the remaining OFDM symbols in the subframe;
obtaining a final signal based on a first OFDM symbol of the subframe and the rest OFDM symbols in the subframe;
wherein the signal comprises: a subframe consisting of 7 OFDM symbols, wherein each subframe consists of a first part and a second part, the first part is a first OFDM symbol with a reserved cyclic prefix, and the second part is 6 OFDM symbols with the removed cyclic prefix;
the performing channel estimation on each subframe in the signal and a first orthogonal frequency division multiplexing OFDM symbol of a subframe next to the subframe, eliminating interference between remaining OFDM symbols in the subframe, and obtaining the remaining OFDM symbols in the subframe includes:
obtaining time domain channel impulse response of a first OFDM symbol in a subframe based on channel frequency response of channel estimation;
extracting taps from the time-domain channel impulse response based on threshold detection;
acquiring intersymbol interference of the first part to the second part in the subframe based on the tap;
obtaining a second part signal for eliminating the intersymbol interference based on the intersymbol interference of the first part to the second part;
obtaining an inter-symbol interference component based on a cyclic prefix of a first OFDM symbol in a next transmission time interval;
replacing inter-carrier interference of the first portion to the second portion based on the inter-symbol interference component;
obtaining a second part signal based on the second part signal for eliminating the intersymbol interference and the intersymbol interference component;
the intersymbol interference component is expressed by the following formula:
Figure FDA0003781278370000011
in the formula: ISI (inter-symbol interference) TTI+1 [n]: an intersymbol interference component;
Figure FDA0003781278370000012
a first OFDM symbol in a first portion of a next transmission time interval that does not include a cyclic prefix; n' taps : the number of taps of the first OFDM symbol in the next transmission time interval; a' j : complex amplitude of j taps of the first OFDM symbol in the next transmission time interval; tau' j : the delay associated with j taps for the first OFDM symbol in the next transmission time interval;
Figure FDA0003781278370000021
transmitting a signal in the time domain of a first OFDM symbol not including the cyclic prefix in a first part of a next transmission time interval; n is a radical of OFDM : removing the OFDM symbol length after the cyclic prefix; n: a time index; n is a radical of CP : the length of the cyclic prefix.
2. The method of claim 1, wherein the time-domain channel impulse response of the first OFDM symbol is calculated as:
Figure FDA0003781278370000022
in the formula: h [ n ]]: a time domain channel impulse response; n is a radical of hydrogen taps : the number of taps; a is j : complex amplitude of tap j times; n: a time index; tau is j : the delay associated with j taps.
3. The method of claim 2, wherein the first portion interferes with the second portion intersymbol interference as follows:
Figure FDA0003781278370000023
in the formula: ISI: intersymbol interference of the first portion with the second portion;
Figure FDA0003781278370000024
a time domain transmit signal of a first OFDM symbol in the first portion that does not include a cyclic prefix; n is a radical of OFDM : removing the length of the OFDM symbol after the cyclic prefix; tau is max : the maximum value of the channel delay.
4. The method of claim 3, wherein the second portion of the signal for canceling intersymbol interference is represented by the following equation:
Figure FDA0003781278370000025
in the formula:
Figure FDA0003781278370000026
a second part signal for eliminating intersymbol interference;
Figure FDA0003781278370000027
a first OFDM symbol in the first portion that does not include a cyclic prefix;
Figure FDA0003781278370000028
the remaining 6 OFDM symbols in the second part.
5. The method of claim 1, wherein the second portion of the signal is represented by the following equation:
Figure FDA0003781278370000031
in the formula:
Figure FDA0003781278370000032
a second portion of the signal;
Figure FDA0003781278370000033
and eliminating the second part signal of the intersymbol interference.
6. The method of claim 1, wherein the transmission method in the long term evolution communication system further comprises:
generating control information and information blocks to be transmitted into signals consisting of subframes;
and transmitting the signal based on the preprocessed physical channel.
7. The method of claim 6, wherein generating the control information and information blocks to be transmitted as a signal consisting of subframes comprises:
mapping the control information to subcarriers to generate frequency domain components of a first OFDM symbol;
after the frequency domain component of the first OFDM symbol passes through an Inverse Fast Fourier Transform (IFFT), inserting a cyclic prefix to obtain a first part of the subframe;
adding protection to the information block through Forward Error Correction (FEC) coding;
obtaining an information target block based on the interleaver compensating the frequency diversity loss in the information block;
obtaining a second part of the subframe for the information target block based on subcarrier mapping and Inverse Fast Fourier Transform (IFFT);
and cascading the first part and the second part to generate a signal consisting of a subframe.
8. The method of claim 1, wherein the pre-processing the physical channel comprises:
and the physical channel is composed based on a Physical Uplink Control Channel (PUCCH) and an enhanced downlink physical control channel (EPDCCH).
9. The method of claim 1, wherein the signal further comprises: a sub-frame consisting of 14 OFDM symbols, wherein all 14 OFDM symbols in the sub-frame contain cyclic prefixes.
10. The method as claimed in claim 9, wherein after receiving the signal using the pre-processed physical channel and before obtaining a final signal based on the first OFDM symbol of the sub-frame and the remaining OFDM symbols of the sub-frame, further comprising:
detecting each sub-frame in the signal, when the number of the cyclic prefixes in the sub-frames is 1,
performing channel estimation on the subframe and a first Orthogonal Frequency Division Multiplexing (OFDM) symbol of a next subframe of the subframe, eliminating interference among remaining OFDM symbols in the subframe, and obtaining the remaining OFDM symbols in the subframe;
otherwise, the final signal is obtained based on 14 OFDM symbols.
11. A transmission system in a long term evolution communication system employing the transmission method in the long term evolution communication system according to any of the claims 1 to 10, characterized by comprising:
the receiving module is used for receiving signals by adopting a preprocessed physical channel;
an interference elimination module, configured to perform channel estimation on each subframe in the signal and a first OFDM symbol of a subframe next to the subframe, eliminate interference between remaining OFDM symbols in the subframe, and obtain remaining OFDM symbols in the subframe;
a result module, configured to obtain a final signal based on a first OFDM symbol of the subframe and remaining OFDM symbols in the subframe;
wherein the signal comprises: the OFDM signal transmission method comprises subframes composed of 7 OFDM symbols, wherein each subframe is composed of a first part and a second part, the first part is a first OFDM symbol with a reserved cyclic prefix, and the second part is 6 OFDM symbols with the removed cyclic prefix.
12. The system of claim 11, wherein the interference cancellation module comprises:
the obtaining time domain channel impulse response unit is used for obtaining the time domain channel impulse response of the first OFDM symbol in the subframe based on the channel frequency response of the channel estimation;
an extraction tap unit for extracting a tap from the time domain channel impulse response based on threshold detection;
an inter-symbol interference unit for obtaining inter-symbol interference of the first part to the second part in the subframe based on the tap;
an inter-symbol interference elimination unit, configured to obtain a second partial signal for eliminating inter-symbol interference based on inter-symbol interference of the first part to the second part;
an inter-symbol interference component obtaining unit, configured to obtain an inter-symbol interference component based on a cyclic prefix of a first OFDM symbol in a next transmission time interval;
a replace inter-carrier interference unit to replace inter-carrier interference of the first portion to the second portion based on the inter-symbol interference component;
and a second partial signal unit for obtaining a second partial signal based on the second partial signal for canceling the intersymbol interference and the intersymbol interference component.
13. A method for transmission in a long term evolution communication system, comprising:
mapping control information to be sent on the basis of subcarriers and inserting cyclic prefixes to obtain a first part;
adding protection to an information block to be sent based on Forward Error Correction (FEC) coding, and compensating frequency diversity loss in the information block through an interleaver to obtain a second part;
transmitting signals generated by cascading the first part and the second part based on a preprocessed physical channel;
the first part is a first OFDM symbol with a reserved cyclic prefix, and the second part is 6 OFDM symbols with the removed cyclic prefix;
the obtaining a first part of the control information to be sent based on subcarrier mapping and insertion of a cyclic prefix comprises:
mapping the control information to subcarriers to generate frequency domain components of a first OFDM symbol;
after the frequency domain component of the first OFDM symbol passes through an Inverse Fast Fourier Transform (IFFT), inserting a cyclic prefix to obtain a first part of a subframe;
the adding protection to the information block to be sent based on forward error correction, FEC, coding and the compensating for the frequency diversity loss in the information block by the interleaver to obtain a second part, includes:
adding protection to the information block through Forward Error Correction (FEC) coding;
obtaining an information target block based on the interleaver compensating the frequency diversity loss in the information block;
and obtaining a second part of the subframe for the information target block based on subcarrier mapping and Inverse Fast Fourier Transform (IFFT).
14. The method of claim 13, wherein the pre-processing the physical channel comprises:
and the physical channel is composed of a Physical Uplink Control Channel (PUCCH) and an enhanced downlink physical control channel (EPDCCH).
15. A transmission system in a long term evolution communication system employing the transmission method in the long term evolution communication system according to any of the claims 13-14, characterized by comprising: a first generating module, configured to map and insert a cyclic prefix into control information to be sent based on subcarriers to obtain a first part;
a second generating module, configured to add protection to an information block to be sent based on forward error correction FEC coding, and obtain a second part by compensating for frequency diversity loss in the information block through an interleaver;
a transmitting module, configured to transmit a signal generated by cascading the first part and the second part based on a pre-processed physical channel;
the first part is the first OFDM symbol with the cyclic prefix reserved, and the second part is 6 OFDM symbols with the cyclic prefix removed.
16. The system of claim 15, wherein the first generation module comprises:
a frequency domain component generating unit, configured to map the control information to a subcarrier to generate a frequency domain component of a first OFDM symbol;
and a first part obtaining unit, configured to insert a cyclic prefix after the frequency domain component of the first OFDM symbol is subjected to Inverse Fast Fourier Transform (IFFT) to obtain a first part of the subframe.
CN201910042680.6A 2019-01-17 2019-01-17 Transmission method and system in long-term evolution communication system Active CN111447162B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910042680.6A CN111447162B (en) 2019-01-17 2019-01-17 Transmission method and system in long-term evolution communication system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910042680.6A CN111447162B (en) 2019-01-17 2019-01-17 Transmission method and system in long-term evolution communication system

Publications (2)

Publication Number Publication Date
CN111447162A CN111447162A (en) 2020-07-24
CN111447162B true CN111447162B (en) 2022-11-25

Family

ID=71652292

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910042680.6A Active CN111447162B (en) 2019-01-17 2019-01-17 Transmission method and system in long-term evolution communication system

Country Status (1)

Country Link
CN (1) CN111447162B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20080035992A (en) * 2006-10-19 2008-04-24 한국전자통신연구원 Cell search and bch demodulation method for ofdm system
CN101505180A (en) * 2009-03-17 2009-08-12 中兴通讯股份有限公司 CSI reference signal bearing method and apparatus in long term evolution system
CN102325103A (en) * 2011-09-01 2012-01-18 北京交通大学 Reference signal designing method and system for LTE-A (Long Term Evolution-Advanced) system expansion CP (Content Provider)
WO2016001930A1 (en) * 2014-07-03 2016-01-07 Technion Research & Development Foundation Limited System and method for ofdm symbol receiving and processing
CN109076569A (en) * 2016-05-13 2018-12-21 华为技术有限公司 A kind of transmission method and device of ascending control information

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20080035992A (en) * 2006-10-19 2008-04-24 한국전자통신연구원 Cell search and bch demodulation method for ofdm system
CN101505180A (en) * 2009-03-17 2009-08-12 中兴通讯股份有限公司 CSI reference signal bearing method and apparatus in long term evolution system
CN102325103A (en) * 2011-09-01 2012-01-18 北京交通大学 Reference signal designing method and system for LTE-A (Long Term Evolution-Advanced) system expansion CP (Content Provider)
WO2016001930A1 (en) * 2014-07-03 2016-01-07 Technion Research & Development Foundation Limited System and method for ofdm symbol receiving and processing
CN109076569A (en) * 2016-05-13 2018-12-21 华为技术有限公司 A kind of transmission method and device of ascending control information

Also Published As

Publication number Publication date
CN111447162A (en) 2020-07-24

Similar Documents

Publication Publication Date Title
US11743894B2 (en) Subframe structure with embedded control signaling
EP3437284B1 (en) Methods and procedures to improve physical layer efficiency using unique word (uw) discrete fourier transform spread orthogonal frequency division multiplexing (dft-s-ofdm)
US8730854B2 (en) Timing adjustments in a communication system
US9780915B2 (en) Method and system of cyclic prefix overhead reduction for enabling cancellation of inter-symbol and inter-carrier interferences in OFDM wireless communication networks
JP5654031B2 (en) Multiplexing of data and reference information in a wireless communication system
US20130022090A1 (en) Dynamic Cyclic Prefix Mode for Uplink Radio Resource Management
US8189516B2 (en) Apparatus and method for transmitting/receiving packet data control channel in an OFDMA wireless communication system
US20150372843A1 (en) Pulse-shaped orthogonal frequency division multiplexing
TWI663857B (en) User device for communicating data and method
JP2012503445A (en) Method and apparatus for multiplexing data and reference signals in a wireless communication system
US20070217328A1 (en) Method for OFDM Transmission With Low Latency, A Base Station, A User Terminal And A Network Therefor
Lorca Cyclic prefix overhead reduction for low-latency wireless communications in OFDM
US20190044691A1 (en) Uplink (ul) frequency-division duplex (fdd) subframe
US20170214559A1 (en) Transmission/reception of a partial sc-fdm symbol
US11082075B2 (en) Automatic gain control symbol partial use for decoding
CN111447162B (en) Transmission method and system in long-term evolution communication system
Surgiewicz et al. LTE uplink transmission scheme
AU2016344160B2 (en) Dynamic subframe structure
US11050449B1 (en) System and method for extensionless adaptive transmitter and receiver windowing
US9369322B2 (en) Method of decoding a received SC-FDMA symbol in a receiver in a OFDM communication system, a receiver, an apparatus, an OFDM communication system and a computer program product
US20240146596A1 (en) Flow optimization method for non-real-time decoding systems
CN115176446B (en) Apparatus and method for cyclic prefix based time and/or frequency correction
CN110365617B (en) Multi-user orthogonal frequency division multiple access receiving method and device based on space-time reference
Elsaadany et al. Fast-decoding channel estimation technique for downlink control channel in LTE-MTC systems
Takeda et al. Investigation on rate matching and soft buffer splitting for LTE-advanced carrier aggregation

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant