WO2016179838A1

WO2016179838A1 - Method and apparatus for signal transmission

Info

Publication number: WO2016179838A1
Application number: PCT/CN2015/078978
Authority: WO
Inventors: Hongmei Liu; Lei Jiang; Gang Wang
Original assignee: Nec Corporation
Priority date: 2015-05-14
Filing date: 2015-05-14
Publication date: 2016-11-17

Abstract

Embodiments of the disclosure provide a method and apparatus for signal transmission. The method may comprise: determining, based on at least one basic signal, an initial signal to be transmitted for transmission initialization; and transmitting the initial signal in a part of a symbol, without using at least a part of the symbol.

Description

METHOD AND APPARATUS FOR SIGNAL TRANSMISSION

FIELD OF THE INVENTION

Embodiments of the present invention generally relate to communication techniques. More particularly， embodiments of the present invention relate to a method and apparatus for signal transmission.

BACKGROUND OF THE INVENTION

For a communication system， it is important to perform transmission initialization before data communication， so as to carry out time/frequency synchronization， Automatic Gain Control (AGC) setting， cell identification， Radio Resource Management (RRM) measurement， and so on.

Traditionally， the communication system uses periodical initial signals in transmission initialization. The initial signals may comprise a Primary Synchronization Signal (PSS) ， a Secondary Synchronization Signal (SSS) ， a Common Reference Signal (CRS) ， Channel state information reference signal (CSI-RS) and/or the like.

In recent years， due to the rare resources， licensed carriers and unlicensed carriers are used in the communication system. A licensed carrier represents a frequency band that is exclusively licensed to a specific operator to provide specific wireless services. An unlicensed carrier represents a frequency band that is not allocated to a specific operator， but is opened so that all entities meeting the predefined requirements may use the frequency band.

However， for Licensed-Assisted Access (LAA) on the unlicensed carrier， the carrier availability is uncertain due to contention before access. As a result， the periodical initial signals can’t be guaranteed. Additionally， a single transmission duration is restricted by the maximum channel occupancy time according to the regulations.

Therefore， there is a need for a scheme for transmitting the initial signal， especially in the case of uncertain carrier availability.

SUMMARY OF THE INVENTION

The present invention proposes a solution regarding transmitting the initial signal.

According to a first aspect of embodiments of the present invention， embodiments of the invention provide a method for signal transmission. The method comprises： determining， based on at least one basic signal， an initial signal to be transmitted for transmission initialization； and transmitting the initial signal in a part of a symbol， without using at least a part of the symbol. The method may be performed at a transmitter， such as base station (BS) .

According to a second aspect of embodiments of the present invention， embodiments of the invention provide a method for signal transmission. The method comprises： receiving an initial signal in a part of a symbol for transmission initialization， wherein the initial signal is determined based on at least one basic signal， and wherein the initial signal is received without using at least part of the symbol. The method may be performed at a receiver， such as user equipment (UE) or a BS near the transmitter.

According to a third aspect of embodiments of the present invention， embodiments of the invention provide an apparatus for signal transmission. The apparatus comprises： a determining unit configured to determine an initial signal to be transmitted for transmission initialization based on at least one basic signal； and a transmitting unit configured to transmit the initial signal in a part of a symbol， without using at least a part of the symbol. The apparatus may be implemented at the transmitter.

According to a fourth aspect of embodiments of the present invention， embodiments of the invention provide an apparatus for signal transmission. The apparatus comprises： a receiving unit configured to receive an initial signal in a part of a symbol for transmission initialization， wherein the initial signal is determined based on at least one basic signal， and wherein the initial signal is received without using at least part of the symbol. The apparatus may be implemented at the receiver.

Other features and advantages of the embodiments of the present invention will also be apparent from the following description of specific embodiments when read in conjunction with the accompanying drawings， which illustrate， by way of example， the principles of embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are presented in the sense of examples and their advantages are explained in greater detail below， with reference to the accompanying drawings， where

FIG. 1 illustrates a schematic diagram of a communication system according to embodiments of the invention；

FIG. 2 illustrates a flow chart of a method for signal transmission at a transmitter according to embodiments of the invention；

FIG. 3 illustrates a flow chart of a method for initial signal determination at a transmitter according to embodiments of the invention；

FIG. 4 illustrates a flow chart of a method for initial signal determination at a transmitter according to further embodiments of the invention；

FIG. 5 illustrates a flow chart of a method for signal transmission at a receiver according to embodiments of the invention；

FIG. 6 illustrates a schematic diagram of resource units used by a basic signal according to embodiments of the present invention；

FIG. 7 illustrates a schematic diagram of resource units used by a spread basic signal according to embodiments of the present invention；

FIG. 8 illustrates a schematic diagram of resource units used by a spread basic signal according to further embodiments of the invention；

FIG. 9 illustrates a schematic diagram of resource units used by a spread basic signal according to still further embodiments of the invention；

FIG. 10 illustrates a schematic diagram of resource units used by a spread basic signal according to still further embodiments of the invention；

FIG. 11 illustrates a schematic diagram of a symbol according to embodiments of the invention；

FIG. 12 illustrates a schematic diagram of an apparatus for signal transmission at a transmitter according to embodiments of the invention； and

FIG. 13 illustrates a schematic diagram of an apparatus for signal transmission at a receiver according to embodiments of the invention.

Throughout the figures， same or similar reference numbers indicate same or similar elements.

DETAILED DESCRIPTION OF EMBODIMENTS

The subject matter described herein will now be discussed with reference to several example embodiments. It should be understood these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the subject matter described herein， rather than suggesting any limitations on the scope of the subject matter.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein， the singular forms “a， ” “an” and “the” are intended to include the plural forms as well， unless the context clearly indicates otherwise. It will be further understood that the terms “comprises， ” “comprising， ” “includes” and/or “including， ” when used herein， specify the presence of stated features， integers， steps， operations， elements and/or components， but do not preclude the presence or addition of one or more other features， integers， steps， operations， elements， components and/or groups thereof.

It should also be noted that in some alternative implementations， the functions/acts noted may occur out of the order noted in the figures. For example， two functions or acts shown in succession may in fact be executed concurrently or may sometimes be executed in the reverse order， depending upon the functionality/acts involved.

As used herein， the term “base station” or “BS” represents a node B (NodeB or NB) ， an evolved NodeB (eNodeB or eNB) ， a Remote Radio Unit (RRU) ， a radio header (RH) ， a remote radio head (RRH) ， a relay， a low power node such as a femto， a pico， and so forth.

As used herein， the term “user equipment” or “UE” refers to any device that is capable of communicating with the BS. By way of example， the UE may include a terminal， a Mobile Terminal (MT) ， a Subscriber Station (SS) ， a Portable Subscriber Station， a Mobile Station (MS) ， or an Access Terminal (AT) .

Embodiments of the present invention may be applied in various communication systems， including but not limited to a Long Term Evolution (LTE) system or a Long Term Evolution Advanced (LTE-A) system. Given the rapid development in communications， there will of course also be future type wireless communication technologies and systems with which the present invention may be embodied. It should not be seen as limiting the scope of the invention to only the aforementioned system.

Now some exemplary embodiments of the present invention will be described below with reference to the figures. Reference is first made to FIG. 1， which illustrates a schematic diagram of a communication system according to embodiments of the invention.

In the communication system shown in FIG. 1， a BS 110 is to communicate with a UE 120 and has two neighboring

BSs

130 and 140. Before communicating， transmission initialization may be performed. By way of example， the BS 110 may send a PSS and/or SSS to the UE 120， so that time/frequency synchronization， AGC setting， cell identification， channel reservation， RRM measurement， and so on may be implemented. In some cases， the PSS and/or SSS are broadcasted from the BS 110. Thus， not only the UE 120 but also the neighboring

BSs

130 and 140 may listen to the broadcasted PSS and/or SSS respectively， so as to perform transmission initialization in consideration of the PSS and/or SSS received from the BS 110.

It is to be understood that the above example embodiments are only for the purpose of illustration， without suggesting any limitations on the subject matter described herein. According to embodiments of the present invention， there may be one or more UEs that are to communicate with the BS 110， and there may be one or more neighboring BSs near the BS 110. Although only one UE 120 and two neighboring

BSs

130 and 140 are shown in FIG. 1， embodiments of the present may be implemented by using different number of UEs and neighboring BSs.

Reference is now made to FIG. 2， which illustrates a flow chart of a method 200 for signal transmission at a BS according to embodiments of the invention. According to embodiments of the present invention， the method 200 may be performed at a transmitter， for example， the BS 110 of FIG. 1.

At step S210， an initial signal is determined to be transmitted for transmission initialization based on at least one basic signal.

According to embodiments of the present invention， the initial signal may be a signal used in transmission initialization for carrying out time/frequency synchronization， AGC setting， cell identification， channel reservation， RRM measurement， and so on. In embodiments of the present invention， there may be one or more initial signals determined and transmitted. If there is only one initial signal， the time duration of the initial signal is less than the time duration of a symbol， and the initial signal is transmitted in only a part of the symbol. If there are a plurality of initial signals， the time duration of each of the plurality of initial signals is less than the time duration of a symbol， and each of the initial signals is transmitted in only a part of the symbol. In other words， according to embodiments of the present invention， none of the initial signal (s) has the time duration equal to or larger than a symbol.

According to embodiments of the present invention， during the determination of the initial signal， at least one basic signal may be determined first based on a cell or an operator to which the cell belongs. In some cases， the BS may have the knowledge of identification of the cell it manages and the operator to which the cell belongs. For example， the cell managed by the BS may be “CELL 001” belonging to “OPERATOR A” . With the above knowledge， the BS may determine at least one basic signal for the cell or the operator. In some embodiments， the BS may select a sequence for use in code division multiplexing， so as to differentiate the initial signal associated with the cell or the operator from an initial signal associated with other cells or operators. Then， the BS may determine the at least one basic signal based on the selected sequence.

According to embodiments of the present invention， at step S210， the initial signal may be determined based on the at least one basic signal. In this disclosure， a basic signal may be a synchronization signal， for example a PSS or a SSS. In some embodiments， the at least one basic signal may comprise at least one of a PSS and a SSS. Additionally， in some embodiments， the at least one basic signal may further comprise a CRS， a CSI-RS and/or the like.

The initial signal may be determined based on the PSS， the SSS， or both the PSS and the SSS. According to embodiments of the present invention， the initial signal may be determined in several ways. In some embodiments， the at least one basic signal may be spread in a frequency domain， and then be transformed from the frequency domain to a time domain， to obtain at least one time-domain basic signal. Then， the initial signal may be determined based on a part of the at least one time-domain basic signal. The time-domain basic signal may be periodical， and the determined initial signal may comprise at least a period or at least a part of a period of the at least one time-domain basic signal. Related details may be found in descriptions with reference to FIG. 3.

Alternatively， in some embodiments， the initial signal may be determined as follows. First， the at least one basic signal is transformed from a frequency domain to a time domain， to obtain at least one time-domain basic signal， wherein time duration of the at least one time-domain basic signal is less than time duration of the symbol. Then， the initial signal is determined based on the at least one time-domain basic signal. Related details may be found in descriptions with reference to FIG. 4.

According to embodiments of the present invention， the BS may determine a pattern associated with an operator， and encode the initial signal based on the pattern. In this way， when a UE or a neighboring BS receives the initial signal， it may determine the operator by identifying the pattern.

At step S220， the initial signal is transmitted in a part of a symbol， without using at least a part of the symbol.

According to embodiments of the present invention， the time duration of the initial signal is less than the time duration of a symbol. At step S220， the initial signal is transmitted in a part of a symbol， rather than the whole of the symbol. In other words， at least a part of the symbol is always unused by the transmission of the initial signal.

In some cases， due to certain reasons， a portion of the symbol may be unavailable for transmission of the initial signal. According to embodiments of the present invention， the BS may detect a time point at which the symbol is available and then transmit the initial signal in a part of the symbol after the time point. In this case， what is transmitted from the BS may be a punctured initial signal， which comprises only a portion of the initial signal.

FIG. 11 illustrates a schematic diagram of a symbol according to embodiments of the invention. As shown in FIG. 11， the symbol exemplarily comprises 16 samples， wherein the first 10 samples are unavailable for transmission of the initial signal. At the time point 1101， the BS (for example， the BS 110 of FIG. 1) may detect that the symbol becomes available and transmit the initial signal in the available part of the symbol. For example， if the initial signal determined at step S210 is represented by a sequence [b11 b12 b13 b14， b11 b12 b13 b14] ， the punctured initial signal may be [b13 b 14， b 11 b 12 b 13 b 14] and may be transmitted in the remaining 6 samples after the time point 1101.

Reference is now made to FIG. 3， which illustrates a flow chart of a method 300 for initial signal determination at a transmitter according to embodiments of the invention. The method 300 may be considered as a specific implementation of step S210 of the method 200. However， it is noted that this is only for the purpose of illustrating the principles of the present invention， rather than limiting the scope thereof.

At step S310， the at least one basic signal is spread in a frequency domain.

As discussed above， a basic signal may be a synchronization signal， for example a PSS or a SSS. FIG. 6 illustrates a schematic diagram of resource units used by a basic signal according to embodiments of the present invention. In FIG. 6， a block， for example block 611， represents a resource unit. The resource unit is a part of a resource element. In other words， a resource element comprises a group of resource units. A resource element corresponds to a symbol in terms of time and corresponds to a carrier (for example， 15kHz) in terms of frequency. In embodiments of the present invention， a resource unit corresponds to a part of a symbol (for example， a sample) in terms of time and corresponds to a subcarrier in terms of frequency. As shown in FIG. 6， a symbol is divided into 16 samples， and each sample corresponds to a column. With regard to column 610， the basic signal uses

resource units

611， 612， 613 and 614， which are shown with oblique lines. Other resource units used by the basic signal in other parts of the symbol are also shown with oblique lines in FIG. 6.

There may be several ways to spread the basic signal in the frequency domain. In some embodiments， the

continuous resource units

611， 612， 613 and 614 may be replaced with discontinuous ones. FIG. 7 illustrates a schematic diagram of resource units used by a spread basic signal according to embodiments of the present invention. As shown in FIG. 7， after spreading the basic signal in the frequency domain， the spread basic signal may use the

discontinuous resource units

711， 712， 713 and 714， instead of the

continuous resource units

611， 612， 613 and 614. It is to be noted that although FIG. 7 shows that the interval of the

resource units

711， 712， 713 and 714 are 4， it is only for purpose of illustration rather than limitation. Those skilled in the art may use any other suitable interval to spread the basic signal in the frequency domain.

At step S320， the at least one spread basic signal is transformed from the frequency domain to a time domain， to obtain at least one time-domain basic signal.

In some embodiments， the transformation from the frequency domain to a time domain may be implemented by means of Inverse Fast Fourier Transform (IFFT) or other suitable algorithms. The length of the IFFT may be determined based on the length of the spread frequency domain basic signal. For example， the length of the IFFT for the spread basic signal may be 2048 for the 20MHz system bandwidth.

At step S330， the initial signal is determined based on a part of the at least one time-domain basic signal.

Since the basic signal is spread in the frequency domain， the corresponding time-domain basic signal is periodical. For example， if a frequency domain sequence of a basic signal is [0 0 0 0 0 0 a11 a12 a13 a14 0 0 0 0 0 0] ， the frequency domain sequence of the spread basic signal may be [0 a11 0 0 0 a12 0 0 0 a13 0 0 0 a14 0 0] ， and the corresponding time domain sequence may be [b11 b12 b13 b14， b11 b12 b13 b14， b11 b12 b13 b14， b11 b12 b13 b14] . The a11， a12， a13 or a14 represents a subcarrier that carries a portion of the basic signal in the frequency domain， and “0” indicates a subcarrier that does not carry any portion of the basic signal in the frequency domain. “b11 b12 b13 b14” indicates a period of the time domain sequence， and b11， b12， b13 or b14 represents a sample in the time domain. In the above embodiments， after spreading in the frequency domain， the time domain periodicity is 4 samples. While without the spreading， the time domain periodicity is 16 samples.

The initial signal may be determined based on at least a period of the at least one time-domain basic signal. The determined initial signal may comprise one or more integral periods of the at least one time-domain basic signal， for example， 1 period， 2 periods and so on. In some embodiments， the initial signal may be represented as [b11 b12 b13 b14] or [b11 b12 b13 b14， 0 0 0 0， 0 0 0 0， 0 0 0 0] . Alternatively， the initial signal may be represented as [b11 b12 b13 b14， b11 b12 b13 b14] ， or may be represented as [b11 b12 b13 b14， b11 b12 b13 b14， b11 b12b13 b14， b11 b12b13 b14] ， or the like.

In some alternative embodiments， the determined initial signal may comprise a non-integral period of the at least one time-domain basic signal， for example， one and a half period and so on. Since a period of the time-domain basic signal have the full information of the frequency domain sequence， if the initial signal comprises at least one period of the time-domain basic signal， the receiver (such as the UE or neighboring BS) which receives the initial signal may perform initialization properly based on thereon. For example， the initial signal may be determined as [b11 b12 b13 b14， b11 b12 0 0， 0 0 0 0， 0 0 0 0] .

In some alternative embodiments， the initial signal may be determined based on at least a part of a period of the at least one time-domain basic signal. For example， the determined initial signal may comprise a half period or a quarter period of the at least one time-domain basic signal. In this case， if the receiver (such as the UE or neighboring BS) receives the initial signal， it may understand that the initial signal is used for channel reservation， and the initial signal for synchronization or cell identification may be received in the next symbol. For example， the initial signal may be determined as [b11 b12 0 0， 0 0 0 0， 0 0 0 0， 0 0 0 0] .

It is to be understood that the above example embodiments are only for the purpose of illustration， without suggesting any limitations on the subject matter described herein. The at least one basic signal may be spread in the frequency domain in any other suitable ways.

In some embodiments， there may more than one basic signal. For example， there may be two basic signals， PSS and SSS， and both of the basic signals may be spread in a frequency domain. FIG. 8 illustrates a schematic diagram of resource units used by a spread basic signal according to further embodiments of the invention. As shown in FIG. 8， a half of the resource units (shown with the oblique lines) are used by the PSS and the other half of the resource units (shown with the vertical lines) are used by the SSS. In this case， the initial signals may be represented as [b11 b12 b13 b14， b11 b12 b13 b14， c11 c12 c13 c14， c11 c12 c13 c14] ， wherein the sequence [b11 b12 b13 b14] represents the PSS for cell 1， and the sequence [c11 c12 c13 c14] represents the SSS for cell 1. Alternatively， in some embodiments， the initial signals may be represented as [b11 b12 b13 b14， 0 0 0 0， c11 c12 c13 c14， 0 0 0 0] .

As an alternative， FIG. 9 illustrates a schematic diagram of resource units used by a spread basic signal according to embodiments of the invention. As shown in FIG. 9， a first quarter of the resource units are used by the PSS， a second quarter of the resource units are used by the SSS， a third quarter of the resource units are used by the PSS， and a fourth quarter of the resource units are used by the SSS. In this case， the initial signals may be represented as [b11 b12 b13 b14， c11 c12 c13 c14， b11 b12 b13 b14， c11 c12 c13 c14] ， wherein the sequence [b11 b12 b13 b14] represents the PSS for cell 1， and the sequence [c11 c12 c13 c14] represents the SSS for cell 1. It is to be noted that， the PSS and the SSS as shown in FIG. 9 may be associated with the same cell or different cells. For example， the initial signals may be represented as [b11 b12 b13 b14， c11 c12 c13 c14， b21 b22 b23 b24， c21 c22 c23 c24] ， wherein the sequence [b11 b12 b13 b14] represents the PSS for cell 1， the sequence [c11 c12 c13 c14] represents the SSS for cell 1， the sequence [b21 b22 b23 b24] represents the PSS for cell 2， and the sequence [c21 c22 c23 c24] represents the SSS for cell 2.

As another alternative， FIG. 10 illustrates a schematic diagram of resource units used by a spread basic signal according to further embodiments of the invention. In embodiments of FIG. 10， each quarter of the resource units may be used by the PSS or the SSS， and the PSS and the SSS may be associated with the same cell or different cells. For example， a first quarter of the resource units are used by the PSS or the SSS associated with cell 1， a second quarter of the resource units are used by the PSS or the SSS associated with cell 2， a third quarter of the resource units are used by the PSS or the SSS associated with cell 3， and a fourth quarter of the resource units are used by the PSS or the SSS associated with cell 4. For example， the initial signals may be represented as [b11 b12 b13 b14， b21 b22 b23 b24， b31 b32 b33 b34， b41 b42 b43 b44] ， wherein the sequence [b11 b12 b13 b14] represents the PSS for cell 1， the sequence [b21 b22 b23 b24] represents the PSS for cell 2， the sequence [b31 b32 b33 b34] represents the PSS for cell 3， and the sequence [b41 b42 b43 b44] represents the PSS for cell 4. It is to be noted that there may be several representations for the initial signals， the above example is only for illustration， rather than limitation.

Reference is now made to FIG. 4， which illustrates a flow chart of a method 400 for initial signal determination at a transmitter according to further embodiments of the invention. The method 400 may be considered as a specific implementation of step S210 of the method 200. In the method 400， the basic signal is not spread in the frequency domain. Instead， it is directly transformed from the frequency domain to the time domain， wherein the transformed signal occupies only a part of a symbol. However， it is noted that this is only for the purpose of illustrating the principles of the present invention， rather than limiting the scope thereof.

At step S410， the at least one basic signal is transformed from a frequency domain to a time domain， to obtain at least one time-domain basic signal.

Unlike the embodiments illustrated with reference to FIG. 3， in the embodiments of FIG. 4， the basic signal is transformed from the frequency domain to the time domain directly. During the transformation， the length of the IFFT may be less than that is used in the embodiments of FIG. 3. More specifically， if the length of the IFFT for the spread basic signal is 2048 the embodiments of FIG. 3， the length of the IFFT may be shortened to 64 at step S410. After performing the 64-point IFFT on a basic signal which has the resource units with oblique lines as shown in FIG. 6， a time-domain basic signal which has 64 points may be obtained.

At step S420， the initial signal is determined based on the at least one time-domain basic signal.

In some embodiments， a time-domain basic signal may directly act as an initial signal. Alternatively， the initial signal may comprise more than one time-domain basic signal. For example， the initial signal may comprise one and a half of the time-domain basic signals.

In some alternative embodiments， the initial signal may be determined based on at least a part of the time-domain basic signal. For example， the determined initial signal may comprise a half of the time-domain basic signal. In this case， if a receiver (such as the UE or neighboring BS) receives the initial signal， it may understand that the initial signal is used for channel reservation， and the initial signal for synchronization or cell identification may be received in the next symbol.

According to embodiments of the present invention， the BS may determine a pattern associated with an operator， and encode the initial signal determined according to the

method

300 or 400 based on the pattern. The pattern may be implemented in several ways. In some embodiments， the pattern may be determined based on pattern pool. The pattern pool may be predefined according to system requirements or the like. By way of example， the pattern pool may comprise multiple patterns， such as [1， 1， 1， 1] and [1， -1， 1， -1] ， and information on correspondence between the patterns and operators. For example， the pattern [1， 1， 1， 1] may indicate operator 1 and the pattern [1， -1， 1， -1] may indicate operator 2. The BS may select the pattern [1， -1， 1， -1] and encode the initial signal based on the selected pattern. During the encoding， assuming there are 4 initial signals to be transmitted and each of them is [b11 b12 b13 b14] ， each element of the pattern may be used as a factor for applying to each of the 4 initial signals. For instance， if the 4 initial signals are represented as [b11 b12 b13 b14， b11 b12 b13 b14， b11 b12 b13 b14， b11 b12 b13 b14] ， the initial signals associated with the operator 2 may be encoded as [b11 b12 b13 b14， -b11 -b12-b13 -b14， b11 b12 b13 b14， -b11 -b12 -b13 -b14] . In this way， when a UE or a neighboring BS receives the encoded initial signals， it may determine the operator by identifying the pattern.

With respect to the embodiments of FIG. 8， the time-domain initial signals [b11 b12 b13 b14， b11 b12 b13 b14， c11 c12 c13 c14， c11 c12 c13 c14] may represent operator 1， the time-domain initial signals [b21 b22 b23 b24， -b21 -b22 -b23 -b24， c21 c22 c23 c24， c21 c22 c23 c24] may represent operator 2， and the time-domain initial signals [b31 b32 b33 b34， -b31 -b32 -b33 -b34， c31 c32 c33 c34， -c31 -c32 -c33 -c34] may represent operator 3.

It is to be noted that the above examples are shown for illustration， rather than limitation. Those skilled in the art can use any other suitable pattern (s) within the scope of the present invention.

Reference is now made to FIG. 5， which illustrates a flow chart of a method 500 for signal transmission according to embodiments of the invention. According to embodiments of the present invention， the method 500 may be performed at a receiver， wherein the receiver may be a UE， for example， the UE 120 of FIG. 1， or may be a neighboring BS of the BS that transmits the initial signal， for example the

BS

130 or 140.

At step S510， an initial signal is received in a part of a symbol for transmission initialization， wherein the initial signal is determined based on at least one basic signal， and wherein the initial signal is received without using at least part of the symbol.

According to embodiments of the present invention， the at least one basic signal may comprises at least one ofa PSS and a SSS. In some embodiments， the at least one basic signal may further comprise a CRS， a CSI-RS and/or the like.

In some cases， due to certain reasons， a portion of the symbol may be unavailable for transmission of the initial signal. According to embodiments of the present invention， when receiving the initial signal， a time point at which the symbol is available may be detected first， and then the initial signal may be received in a part of the symbol after the time point.

According to embodiments of the present invention， a cell or an operator to which the cell belongs may be determined based on the initial signal. In some embodiments， upon receiving the initial signal， the receiver (for example， the UE or the neighboring BS) may determine， based on the initial signal， which cell the initial signal comes from.

In some embodiments， a certain number of cells may be allocated to a certain operator in advance. For example， cells 1 to 100 may be pre-allocated to operator 1， cells 101 to 200 may be pre-allocated to operator 2， and cells 201 to 300 may be pre-allocated to operator 3. Thus， when the cell is determined based on the initial signal， the operator to which the cell belongs may be determined as well.

It is to be noted that， by receiving the intimal signal at step S510， the receiver (for example， the UE or the neighboring BS) may perform transmission initialization based on the received initial signal.

As discussed above， the BS may determine a pattern associated with an operator， and encode the initial signal based on the pattern. In this way， when a UE or a neighboring BS receives the initial signal， it may determine the operator by identifying the pattern. In the embodiments illustrated with respect to FIG. 5， the method 500 optionally comprises steps S520 and S530. At step S520， a pattern associated with an operator is identified based on the initial signal. At step S530， the operator is determined based on the pattern.

In some embodiments， after receiving the initial signal， the receiver may determine the factor applied to the initial signal. In this way， the receiver may determine corresponding factors for one or more initial signals. For example， referring back to the embodiments of FIG. 8， if the receiver receives the initial signals [b31 b32 b33 b34， -b31 -b32 -b33 -b34， c31 c32 c33 c34， -c31 -c32 -c33 -c34] ， it may determine that the factor for the initial signal [b31 b32 b33 b34] is 1， the factor for the initial signal [-b31 -b32 -b33 -b34] is -1， the factor for the initial signal [c31 c32 c33 c34] is 1， and the factor for the initial signal [-c31 -c32 -c33 -c34] is -1. Based on the factors， the receiver may identify a pattern， which is [1， -1， 1， -1] . Since the pattern [1， -1， 1， -1] indicates operator 3， the receiver may determine that the received initial signals are associated with operator 3.

FIG. 12 illustrates a schematic diagram of an apparatus 1200 for signal transmission according to embodiments of the invention. According to embodiments of the present invention， the apparatus 1200 may be implemented at a transmitter， such as the BS 110， or any other suitable device.

As shown in FIG. 12， the apparatus 1200 comprises a determining unit 1210 configured to determine an initial signal to be transmitted for transmission initialization based on at least one basic signal； and a transmitting unit 1220 configured to transmit the initial signal in a part of a symbol， without using at least a part of the symbol.

According to embodiments of the present invention， the determining unit 1210 may comprise： a spreading unit configured to spread the at least one basic signal in a frequency domain； a first transforming unit configured to transform the at least one spread basic signal from the frequency domain to a time domain， to obtain at least one time-domain basic signal； and wherein the determining unit 1210 may be further configured to determine the initial signal based on a part of the at least one time-domain basic signal.

According to embodiments of the present invention， wherein the at least one time-domain basic signal may be periodical， and the initial signal may comprise at least a period of the at least one time-domain basic signal.

According to embodiments of the present invention， wherein the at least one time-domain basic signal may be periodical， and the initial signal may comprise at least a part of a period of the at least one time-domain basic signal.

According to embodiments of the present invention， the determining unit 1210 may comprise： a second transforming unit configured to transform the at least one basic signal from a frequency domain to a time domain， to obtain at least one time-domain basic signal， wherein time duration of the at least one time-domain basic signal is less than time duration of the symbol； and wherein the determining unit 1210 may be further configured to determine the initial signal based on the at least one time-domain basic signal.

According to embodiments of the present invention， the determining unit 1210 may comprise： a pattern obtaining unit configured to determine a pattern associated with an operator； and an encoding unit configured to encode the initial signal based on the pattern.

According to embodiments of the present invention， the determining unit 1210 may comprise： a basic signal obtaining unit configured to determine the at least one basic signal based on a cell or an operator to which the cell belongs.

According to embodiments of the present invention， the transmitting unit 1220 may comprise： a detecting unit configured to detect a time point at which the symbol is available； and wherein the transmitting unit 1220 may be further configured to transmit the initial signal in a part of the symbol after the time point.

According to embodiments of the present invention， the at least one basic signal may comprise at least one ofa PSS and a SSS.

FIG. 13 illustrates a schematic diagram of an apparatus 1300 for signal transmission at a UE according to embodiments of the invention. According to embodiments of the present invention， the apparatus 1200 may be implemented at a receiver， such as the UE 120， the BS 130， the BS 140， or any other suitable device.

As shown in FIG. 13， the apparatus 1300 comprises a receiving unit 1310 configured to receive an initial signal in a part of a symbol for transmission initialization， wherein the initial signal is determined based on at least one basic signal， and wherein the initial signal is received without using at least part of the symbol.

According to embodiments of the present invention， the receiving unit 1310 may comprise： a detecting unit configured to detect a time point at which the symbol is available； and wherein the receiving unit 1310 may be further configured to receive the initial signal in a part of the symbol after the time point.

According to embodiments of the present invention， the apparatus 1300 may further comprise a first identifying unit configured to determine a cell or an operator to which the cell belongs based on the initial signal.

According to embodiments of the present invention， the apparatus 1300 may further comprise： a second identifying unit configured to identify a pattern associated with an operator based on the initial signal； and a third identifying unit configured to determine the operator based on the pattern.

It is also to be noted that the

apparatuses

1200 and 1300 may be respectively implemented by any suitable technique either known at present or developed in the future. Further， a single device shown in FIG. 12 or 13 may be alternatively implemented in multiple devices separately， and multiple separated devices may be implemented in a single device. The scope of the present invention is not limited in these regards.

It is noted that the apparatus 1200 may be configured to implement functionalities as described with reference to FIGs. 2 to 4 and the apparatus 1300 may be configured to implement functionalities as described with reference to FIG. 5. Therefore， the features discussed with respect to the

method

200， 300 or 400 may apply to the corresponding components of the apparatus 1200， and the features discussed with respect to the method 500 may apply to the corresponding components of the apparatus 1300. It is further noted that the components of the apparatus 1200 or the apparatus 1300 may be embodied in hardware， software， firmware， and/or any combination thereof. For example， the components of the apparatus 1200 or the apparatus 1300 may be respectively implemented by a circuit， a processor or any other appropriate device. Those skilled in the art will appreciate that the aforesaid examples are only for illustration not limitation.

In some embodiment of the present disclosure， the apparatus 1200 or the apparatus 1300 may comprise at least one processor. The at least one processor suitable for use with embodiments of the present disclosure may include， by way of example， both general and special purpose processors already known or developed in the future. The apparatus 1200 or the apparatus 1300 may further comprise at least one memory. The at least one memory may include， for example， semiconductor memory devices， e.g.， RAM， ROM， EPROM， EEPROM， and flash memory devices. The at least one memory may be used to store program of computer executable instructions. The program can be written in any high-level and/or low-level compliable or interpretable programming languages. In accordance with embodiments， the computer executable instructions may be configured， with the at least one processor， to cause the apparatus 1200 to at least perform according to the

method

200， 300， or 400 as discussed above， or to cause the apparatus 1300 to at least perform according to the method 500 as discussed above.

Based on the above description， the skilled in the art would appreciate that the present disclosure may be embodied in an apparatus， a method， or a computer program product. In general， the various exemplary embodiments may be implemented in hardware or special purpose circuits， software， logic or any combination thereof. For example， some aspects may be implemented in hardware， while other aspects may be implemented in firmware or software which may be executed by a controller， microprocessor or other computing device， although the disclosure is not limited thereto. While various aspects of the exemplary embodiments of this disclosure may be illustrated and described as block diagrams， flowcharts， or using some other pictorial representation， it is well understood that these blocks， apparatus， systems， techniques or methods described herein may be implemented in， as non-limiting examples， hardware， software， firmware， special purpose circuits or logic， general purpose hardware or controller or other computing devices， or some combination thereof.

The various blocks shown in FIGs. 2-5 may be viewed as method steps， and/or as operations that result from operation of computer program code， and/or as a plurality of coupled logic circuit elements constructed to carry out the associated function (s) . At least some aspects of the exemplary embodiments of the disclosures may be practiced in various components such as integrated circuit chips and modules， and that the exemplary embodiments of this disclosure may be realized in an apparatus that is embodied as an integrated circuit， FPGA or ASIC that is configurable to operate in accordance with the exemplary embodiments of the present disclosure.

While this specification contains many specific implementation details， these should not be construed as limitations on the scope of any disclosure or of what may be claimed， but rather as descriptions of features that may be specific to particular embodiments of particular disclosures. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely， various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover， although features may be described above as acting in certain combinations and even initially claimed as such， one or more features from a claimed combination can in some cases be excised from the combination， and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

Similarly， while operations are depicted in the drawings in a particular order， this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order， or that all illustrated operations be performed， to achieve desirable results. In certain circumstances， multitasking and parallel processing may be advantageous. Moreover， the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments， and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

Various modifications， adaptations to the foregoing exemplary embodiments of this disclosure may become apparent to those skilled in the relevant arts in view of the foregoing description， when read in conjunction with the accompanying drawings. Any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this disclosure. Furthermore， other embodiments of the disclosures set forth herein will come to mind to one skilled in the art to which these embodiments of the disclosure pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.

Therefore， it is to be understood that the embodiments of the disclosure are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are used herein， they are used in a generic and descriptive sense only and not for purpose of limitation.

Claims

A method for signal transmission， comprising：

determining， based on at least one basic signal， an initial signal to be transmitted for transmission initialization； and

transmitting the initial signal in a part of a symbol， without using at least a part of the symbol.
The method of Claim 1， wherein determining the initial signal comprises：

spreading the at least one basic signal in a frequency domain；

transforming the at least one spread basic signal from the frequency domain to a time domain， to obtain at least one time-domain basic signal； and

determining the initial signal based on a part of the at least one time-domain basic signal.
The method of Claim 2， wherein the at least one time-domain basic signal is periodical， and the initial signal comprises at least a period of the at least one time-domain basic signal.
The method of Claim 2， wherein the at least one time-domain basic signal is periodical， and the initial signal comprises at least a part of a period of the at least one time-domain basic signal.
The method of Claim 1， wherein determining the initial signal comprises：

transforming the at least one basic signal from a frequency domain to a time domain， to obtain at least one time-domain basic signal， wherein time duration of the at least one time-domain basic signal is less than time duration of the symbol； and

determining the initial signal based on the at least one time-domain basic signal.
The method of Claim 1， wherein determining the initial signal comprises：

determining a pattern associated with an operator； and

encoding the initial signal based on the pattern.
The method of Claim 1， wherein determining the initial signal comprises：

determining the at least one basic signal based on a cell or an operator to which the cell belongs.
The method of Claim 1， wherein transmitting the initial signal comprises：

detecting a time point at which the symbol is available； and

transmitting the initial signal in a part of the symbol after the time point.
The method of any of Claims 1 to 8， wherein the at least one basic signal comprises at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) .
A method for signal transmission， comprising：

receiving an initial signal in a part of a symbol for transmission initialization， wherein the initial signal is determined based on at least one basic signal， and wherein the initial signal is received without using at least part of the symbol.
The method of Claim 10， wherein receiving the initial signal comprises：

detecting a time point at which the symbol is available； and

receiving the initial signal in a part of the symbol after the time point.
The method of Claim 10， further comprising：

determining a cell or an operator to which the cell belongs based on the initial signal.
The method of Claim 10， further comprising：

identifying a pattern associated with an operator based on the initial signal； and

determining the operator based on the pattern.
The method of any of Claims 10-13， wherein the at least one basic signal comprises at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) .
An apparatus for signal transmission， comprising：

a determining unit configured to determine an initial signal to be transmitted for transmission initialization based on at least one basic signal； and

a transmitting unit configured to transmit the initial signal in a part of a symbol， without using at least a part of the symbol.
The apparatus of Claim 15， wherein the determining unit comprises：

a spreading unit configured to spread the at least one basic signal in a frequency domain；

a first transforming unit configured to transform the at least one spread basic signal from the frequency domain to a time domain， to obtain at least one time-domain basic signal； and

wherein the determining unit is further configured to determine the initial signal based on a part of the at least one time-domain basic signal.
The apparatus of Claim 16， wherein the at least one time-domain basic signal is periodical， and the initial signal comprises at least a period of the at least one time-domain basic signal.
The apparatus of Claim 16， wherein the at least one time-domain basic signal is periodical， and the initial signal comprises at least a part of a period of the at least one time-domain basic signal.
The apparatus of Claim 15， wherein the determining unit comprises：

a second transforming unit configured to transform the at least one basic signal from a frequency domain to a time domain， to obtain at least one time-domain basic signal， wherein time duration of the at least one time-domain basic signal is less than time duration of the symbol； and

wherein the determining unit is further configured to determine the initial signal based on the at least one time-domain basic signal.
The apparatus of Claim 15， wherein the determining unit comprises：

a pattern obtaining unit configured to determine a pattern associated with an operator； and

an encoding unit configured to encode the initial signal based on the pattern.
The apparatus of Claim 15， wherein the determining unit comprises：

a basic signal obtaining unit configured to determine the at least one basic signal based on a cell or an operator to which the cell belongs.
The apparatus of Claim 15， wherein the transmitting unit comprises：

a detecting unit configured to detect a time point at which the symbol is available； and

wherein the transmitting unit is further configured to transmit the initial signal in a part of the symbol after the time point.
The apparatus of any of Claims 15 to 22， wherein the at least one basic signal comprises at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) .
An apparatus for signal transmission， comprising：

a receiving unit configured to receive an initial signal in a part of a symbol for transmission initialization， wherein the initial signal is determined based on at least one basic signal， and wherein the initial signal is received without using at least part of the symbol.
The apparatus of Claim 24， wherein the receiving unit comprises：

a detecting unit configured to detect a time point at which the symbol is available； and

wherein the receiving unit is further configured to receive the initial signal in a part of the symbol after the time point.
The apparatus of Claim 24， further comprising：

a first identifying unit configured to determine a cell or an operator to which the cell belongs based on the initial signal.
The apparatus of Claim 24， further comprising：

a second identifying unit configured to identify a pattern associated with an operator based on the initial signal； and

a third identifying unit configured to determine the operator based on the pattern.
The apparatus of any of Claims 24-27， wherein the at least one basic signal comprises at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) .