Devices, methods and computer readable medium for communication
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NEC CORP
- Filing Date
- 2024-12-20
- Publication Date
- 2026-06-25
Smart Images

Figure CN2024141176_25062026_PF_FP_ABST
Abstract
Description
DEVICES, METHODS AND COMPUTER READABLE MEDIUM FOR COMMUNICATIONTECHNICAL FIELD
[0001] Embodiments of the present disclosure generally relate to the field of telecommunication, and in particular, to devices, methods and computer readable medium for communication.BACKGROUND
[0002] Ambient Internet of Thing (AIoT) aims to inventory use case where one or more readers perform an inventory procedure among one or more nearby AIoT devices. Reader may use orthogonal frequency division multiplexing (OFDM) system to generate reader-to-device (R2D) signals, but the R2D signals may not align with a boundary of an OFDM symbol. Padding is agreed to be used for alignment. Thus, there is a need to study how to design the padding.SUMMARY
[0003] In general, example embodiments of the present disclosure provide devices, methods and computer readable medium for communication.
[0004] In a first aspect, there is provided a first device. The first device comprises at least one processor. The at least one processor is configured to cause the first device to: insert padding within transmission from the first device to a second device, before cyclic redundancy check (CRC) attachment to information bits to be transmitted from the first device, after the CRC attachment and before line coding of the information bits, after the line coding and before orthogonal frequency division multiplexing (OFDM) waveform generation for the transmission, during the OFDM waveform generation for the transmission, after the OFDM waveform generation and before postamble attachment to the transmission, after the postamble attachment, or as a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol; and perform the transmission to the second device.
[0005] In a second aspect, there is provided a second device. The second device comprises at least one processor. The at least one processor is configured to cause the second device to: receive transmission from a first device, wherein padding is inserted within the transmission, before CRC attachment to information bits to be transmitted from the first device, after the CRC attachment and before line coding of the information bits, after the line coding and before OFDM waveform generation for the transmission, during the OFDM waveform generation for the transmission, after the OFDM waveform generation and before postamble attachment to the transmission, after the postamble attachment, or as a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol.
[0006] In a third aspect, there is provided a method for communication. The method comprises: inserting, at a first device, padding within transmission from the first device to a second device, before CRC attachment to information bits to be transmitted from the first device, after the CRC attachment and before line coding of the information bits, after the line coding and before OFDM waveform generation for the transmission, during the OFDM waveform generation for the transmission, after the OFDM waveform generation and before postamble attachment to the transmission, after the postamble attachment, or as a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol; and performing the transmission to the second device.
[0007] In a fourth aspect, there is provided a method for communication. The method comprises: receiving transmission at a second device from a first device, wherein padding is inserted within the transmission, before CRC attachment to information bits to be transmitted from the first device, after the CRC attachment and before line coding of the information bits, after the line coding and before OFDM waveform generation for the transmission, during the OFDM waveform generation for the transmission, after the OFDM waveform generation and before postamble attachment to the transmission, after the postamble attachment, or as a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol.
[0008] In a fifth aspect, there is provided a computer readable medium having instructions stored thereon. The instructions, when executed on at least one processor of a device, cause the device to perform the method according to the third or fourth aspect.
[0009] It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Through the more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:
[0011] Fig. 1 illustrates an example communication system in which implementations of the present disclosure can be implemented;
[0012] Fig. 2 illustrates another example communication system in which embodiments of the present disclosure can be implemented;
[0013] Fig. 3A illustrates an example structure for generating physical reader-to-device channel (PRDCH) transmission with postamble;
[0014] Fig. 3B illustrates an example structure for generating PRDCH transmission without postamble;
[0015] Fig. 4 illustrates a signaling diagram illustrating an example process in accordance with some embodiments of the present disclosure;
[0016] Fig. 5 illustrates an example of chips in accordance with some embodiments of the present disclosure;
[0017] Fig. 6 illustrates an example of padding in accordance with some embodiments of the present disclosure;
[0018] Fig. 7 illustrates an example of false rising edge in accordance with some embodiments of the present disclosure;
[0019] Fig. 8A illustrates an example of contents of at least one first padding bit in accordance with some embodiments of the present disclosure;
[0020] Fig. 8B illustrates an example of contents of at least one second padding bit in accordance with some embodiments of the present disclosure;
[0021] Fig. 8C illustrates an example of insertion of at least one padding bit before hopping in accordance with some embodiments of the present disclosure;
[0022] Fig. 8D illustrates an example of insertion of at least one padding bit after hopping in accordance with some embodiments of the present disclosure;
[0023] Fig. 8E illustrates an example of contents of at least one first padding signal in accordance with some embodiments of the present disclosure;
[0024] Fig. 8F illustrates an example of contents of at least one second padding signal in accordance with some embodiments of the present disclosure;
[0025] Fig. 8G illustrates an example of determining a duration of at least one padding signal in accordance with some embodiments of the present disclosure;
[0026] Fig. 9A illustrates an example of contents of at least one third padding signal in accordance with some embodiments of the present disclosure;
[0027] Fig. 9B illustrates an example of contents of at least one fourth padding signal in accordance with some embodiments of the present disclosure;
[0028] Fig. 9C illustrates an example of contents of at least one padding signal in accordance with some embodiments of the present disclosure;
[0029] Figs. 10A, 10B, 10C, 10D and 10E illustrate an example of inserting padding as postamble in accordance with some embodiments of the present disclosure, respectively;
[0030] Fig. 11 illustrates a flowchart of an example method in accordance with some embodiments of the present disclosure;
[0031] Fig. 12 illustrates a flowchart of an example method in accordance with some embodiments of the present disclosure; and
[0032] Fig. 13 is a simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure.
[0033] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION
[0034] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitations as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.
[0035] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.
[0036] As used herein, the term “terminal device” refers to any device having wireless or wired communication capabilities. Examples of the terminal device include, but not limited to, user equipment (UE) , personal computers, desktops, mobile phones, cellular phones, smart phones, personal digital assistants (PDAs) , portable computers, tablets, wearable devices, internet of things (IoT) devices, Ultra-reliable and Low Latency Communications (URLLC) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, device on vehicle for V2X communication where X means pedestrian, vehicle, or infrastructure / network, devices for Integrated Access and Backhaul (IAB) , Small Data Transmission (SDT) , mobility, Multicast and Broadcast Services (MBS) , positioning, dynamic / flexible duplex in commercial networks, reduced capability (RedCap) , Space borne vehicles or Air borne vehicles in Non-terrestrial networks (NTN) including Satellites and High Altitude Platforms (HAPs) encompassing Unmanned Aircraft Systems (UAS) , eXtended Reality (XR) devices including different types of realities such as Augmented Reality (AR) , Mixed Reality (MR) and Virtual Reality (VR) , the unmanned aerial vehicle (UAV) commonly known as a drone which is an aircraft without any human pilot, devices on high speed train (HST) , or image capture devices such as digital cameras, sensors, gaming devices, music storage and playback appliances, or Internet appliances enabling wireless or wired Internet access and browsing and the like. The ‘terminal device’ can further has ‘multicast / broadcast’ feature, to support public safety and mission critical, V2X applications, transparent IPv4 / IPv6 multicast delivery, IPTV, smart TV, radio services, software delivery over wireless, group communications and IoT applications. It may also incorporate one or multiple Subscriber Identity Module (SIM) as known as Multi-SIM. The term “terminal device” can be used interchangeably with a UE, a mobile station, a subscriber station, a mobile terminal, a user terminal or a wireless device.
[0037] The term “network device” refers to a device which is capable of providing or hosting a cell or coverage where terminal devices can communicate. Examples of a network device include, but not limited to, a Node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a next generation NodeB (gNB) , a transmission reception point (TRP) , a remote radio unit (RRU) , a radio head (RH) , a remote radio head (RRH) , an IAB node, a low power node such as a femto node, a pico node, a reconfigurable intelligent surface (RIS) , Network-controlled Repeaters, and the like.
[0038] The terminal device or the network device may have Artificial intelligence (AI) or Machine learning capability. It generally includes a model which has been trained from numerous collected data for a specific function, and can be used to predict some information.
[0039] The terminal or the network device may work on several frequency ranges, e.g. FR1 (410 MHz –7125 MHz) , FR2 (24.25GHz to 71GHz) , frequency band larger than 100GHz as well as Tera Hertz (THz) . It can further work on licensed / unlicensed / shared spectrum. The terminal device may have more than one connection with the network devices under Multi-Radio Dual Connectivity (MR-DC) application scenario. The terminal device or the network device can work on full duplex, flexible duplex and cross division duplex modes.
[0040] The network device may have the function of network energy saving, Self-Organizing Networks (SON) / Minimization of Drive Tests (MDT) . The terminal may have the function of power saving.
[0041] The embodiments of the present disclosure may be performed in test equipment, e.g. signal generator, signal analyzer, spectrum analyzer, network analyzer, test terminal device, test network device, channel emulator.
[0042] The embodiments of the present disclosure may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols, 5.5G, 5G-Advanced networks, or the 6G networks.
[0043] 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. The term ‘includes’ and its variants are to be read as open terms that mean ‘includes, but is not limited to. ’ The term ‘based on’is to be read as ‘at least in part based on. ’ The term ‘some embodiments’ and ‘an embodiment’ are to be read as ‘at least some embodiments. ’ The term ‘another embodiment’ is to be read as ‘at least one other embodiment. ’ The terms ‘first, ’ ‘second, ’ and the like may refer to different or same objects. Other definitions, explicit and implicit, may be included below.
[0044] In some examples, values, procedures, or apparatus are referred to as ‘best, ’ ‘lowest, ’ ‘highest, ’ ‘minimum, ’ ‘maximum, ’ or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many used functional alternatives can be made, and such selections need not be better, smaller, higher, or otherwise preferable to other selections.
[0045] As described above, R2D signals may not align with a boundary of an OFDM symbol. Padding is agreed to be used for alignment. For example, for R2D waveform generation using OFDM-based transmitter, from transmitter perspective, when the generated number of chips for the R2D transmission does not fully occupy the last OFDM symbol, at least padding can be used. Thus, there is a need to study how to insert the padding.
[0046] In view of the above, the present disclosure provides a solution for communication. In this solution, a first device inserts padding within transmission from the first device to a second device, before CRC attachment to information bits to be transmitted from the first device, after the CRC attachment and before line coding of the information bits, after the line coding and before OFDM waveform generation for the transmission, during the OFDM waveform generation for the transmission, after the OFDM waveform generation and before postamble attachment to the transmission or after the postamble attachment, or the first device inserts padding as a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol. In turn, the first device performs the transmission to the second device. With this solution, with the padding, mismatch between signals after line coding and a boundary of an OFDM symbol may be avoided.
[0047] Fig. 1 illustrates an example communication system 100 in which embodiments of the present disclosure can be implemented. As shown in Fig. 1, the communication system 100 may comprise a first device 110 and a second device 120.
[0048] In some embodiments, the communication system 100 may be implemented as an AIoT system. In such embodiments, the first device 110 may be implemented as a communication device, and the second device 120 may be implemented as an AIoT device. In such embodiments, the first device 110 may be referred to as a reader for the AIoT device. The reader can hold an OFDM system for signal transmission.
[0049] In some embodiments, the reader may be implemented as a network device, and the AIoT device may be implemented as a terminal device, such as a tag. In such embodiments, the second device 120 may directly and bidirectionally communicate with the first device 110. The communication between the first device 110 and the second device 120 may comprise at least one of the following: Ambient IoT data or Ambient IoT signalling.
[0050] Alternatively, in some embodiments, the reader may be implemented as an intermediate node between the second device 120 and a network device. For example, the intermediate node may be implemented as multiple terminal devices (such as mobile phones, PDAs and so on) and communicate with a network device, and the AIoT device may be implemented as a terminal device, such as a tag. For another example, the intermediate node may be a relay, IAB node, a UE, or repeater which is capable of Ambient IoT. The second device 120 may communicate bidirectionally with the network device via the first device 110. The first device 110 transfers Ambient IoT data and / or signalling between the second device 120 and the network device.
[0051] It is to be understood that the number of devices shown in Fig. 1 is only for the purpose of illustration. The communication system 100 may include any suitable number of devices and entities.
[0052] Fig. 2 illustrates another example communication system 200 in which embodiments of the present disclosure can be implemented. As shown in Fig. 2, the communication system 200 may comprise the first device 110 and the second device 120 in Fig. 1.
[0053] The second device 120 may be implemented as an AIoT device, and the first device 110 may be implemented as a reader for the AIoT devices. Hereinafter, a transmission from a reader to an AIoT device is also referred to as R2D transmission or PRDCH transmission, and signals from a reader to an AIoT device is also referred to as R2D signals or PRDCH signals.
[0054] In some embodiments, the first device 110 may use OFDM system to generate R2D signals and transmit OFDM-based R2D signals to the second device 120. When the generated number of chips for R2D transmission does not fully occupy the last OFDM symbol, padding can be used for alignment.
[0055] Fig. 3A illustrates an example structure 300A for generating PRDCH transmission with postamble at the first device 110. As shown in Fig. 3A, the structure 300A may comprise a block 310 for CRC attachment, a block 320 for line coding, a block 330 for OFDM waveform generation and a block 340 for postamble attachment.
[0056] The block 310 for CRC attachment may be used for performing CRC attachment to information bits to be transmitted from the first device 110. Hereinafter, the information bits to be transmitted from the first device 110 are also referred to as R2D information bits. In some embodiments, CRC bits may be appended to the R2D information bits if there is non-zero length CRC.
[0057] The block 320 for line coding may be used for performing line coding of the information bits.
[0058] The block 330 for OFDM waveform generation may be used for performing OFDM waveform generation of for transmission from the first device 110 to the second device 120. Hereinafter, transmission from the first device 110 to the second device 120 is also referred to as R2D transmission or PRDCH transmission.
[0059] The block 340 for postamble attachment may be used for performing postamble attachment to the R2D transmission.
[0060] It is to be understood that the number of blocks shown in Fig. 3A is only for the purpose of illustration. The structure for generating PRDCH transmission may include one or more additional blocks.
[0061] Fig. 3B illustrates an example structure 300B for generating PRDCH transmission without postamble at the first device 110. The structure 300B is different from the structure 300A in that the structure 300B does not comprise the block 340 for postamble attachment. Thus, the PRDCH transmission generated with the structure 300B does not comprise postamble.
[0062] Fig. 4 illustrates a signaling diagram illustrating an example process 400 in accordance with some embodiments of the present disclosure. The process 400 may involve the first device 110 and the second device 120 in Fig. 1, 2, 3A or 3B. For the purpose of discussion, the process 400 will be described with reference to Fig. 1, 2, 3A or 3B.
[0063] As shown in Fig. 4, the first device 110 inserts 410 padding within transmission from the first device 110 to the second device 120.
[0064] In turn, the first device 110 performs 420 the transmission to the second device 120.
[0065] In the process 400, with the padding, mismatch between signals after line coding and a boundary of an OFDM symbol may be avoided.
[0066] Hereinafter, locations where the padding is inserted will be described with reference to Figs. 3A and 3B.
[0067] As shown in Figs. 3A and 3B, in case 1, the first device 110 inserts the padding before CRC attachment to information bits to be transmitted from the first device 110. For example, the first device 110 inserts the padding before the block 310 for CRC attachment.
[0068] Alternatively, in case 2, the first device 110 inserts the padding after the CRC attachment and before line coding of the information bits. For example, the first device 110 inserts the padding after the block 310 for the CRC attachment and before the block 320 for the line coding.
[0069] Alternatively, in case 3, the first device 110 inserts the padding after the line coding and before OFDM waveform generation for the R2D transmission. For example, the first device 110 inserts the padding after the block 320 for the line coding and before the block 330 for the OFDM waveform generation.
[0070] Alternatively, in case 4, the first device 110 inserts the padding during the OFDM waveform generation for the R2D transmission. For example, the first device 110 inserts the padding at the block 330 for the OFDM waveform generation.
[0071] Alternatively, in case 5, the first device 110 inserts the padding after the OFDM waveform generation and before postamble attachment to the R2D transmission. For example, the first device 110 inserts the padding after the block 330 for the OFDM waveform generation and before the block 340 for the postamble attachment.
[0072] Alternatively, in case 6, the first device 110 inserts the padding after the postamble attachment. For example, the first device 110 inserts the padding after the block 340 for the postamble attachment.
[0073] Alternatively, in case 7 which is not shown in Fig. 3A or 3B, the first device 110 inserts the padding as a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol.
[0074] It shall be noted that the block diagrams of Figs. 3A and 3B are illustrated only for clarity. In the actual communication system, the blocks in Figs. 3A and 3B can be replaced with corresponding procedures. For example, the block 320 for the line coding can be replaced with a procedure of line coding. The same applies to the blocks 310, 330 and 340.
[0075] In some embodiments, the first device 110 may insert at least one padding bit or at least one padding signal within the R2D transmission.
[0076] In some embodiments, if the first device 110 inserts padding before the block 320 for the line coding, the first device 110 may insert at least one padding bit. If the first device 110 inserts padding after the block 320 for the line coding, the first device 110 may insert at least one padding signal.
[0077] In some embodiments, the first device 110 may transmit, to the second device 120, control information for the R2D transmission. The control information may comprise an indication of a size of the at least one padding bit or a duration of the at least one padding signal.
[0078] In some embodiments, the first device 110 may determine a transport block (TB) size for the R2D transmission based at least on the size of at least one padding bit or the duration of the at least one padding signal. The TB size is the amount of bits from a medium access control (MAC) layer to be transmitted by a physical (PHY) layer.
[0079] In some embodiments, the second device 120 may determine the TB size for the R2D transmission based at least on the size of at least one padding bit or the duration of the at least one padding signal. Hereinafter, some embodiments of determining the TB size will be described by taking the second device 120 for example. The first device 110 may determine the TB size for the R2D transmission in a similar way.
[0080] In some embodiments, the control information may further indicate at least one of the following: time domain resources associated with the R2D transmission, a code rate of the line coding, or a code rate of channel coding. Alternatively, at least one of the following may be predefined: the code rate of the line coding, or the code rate of channel coding.
[0081] In some embodiments, the control information may further indicate information related to a chip duration. For example, the information related to the chip duration may comprise the number of chips carried on a symbol. The chip duration may have the same meaning as a chip length. Thus, the term “chip duration” may be used interchangeably with the term “chip length” . Hereinafter, the number of chips carried on a symbol is represented by M.
[0082] In some embodiments, the second device 120 may can obtain the chip duration through R2D time acquisition signal. For example, the clock-acquisition part of the R2D time acquisition signal is used to determine the on-off keying (OOK) chip duration.
[0083] In some embodiments, a chip may refer to a shortest duration of one high voltage or one low voltage, to be used to convey information bits. This will be described with reference to Fig. 5.
[0084] Fig. 5 illustrates an example of chips in accordance with some embodiments of the present disclosure. In the example of Fig. 5, the OOK modulation may be used by the first device 110. As shown in Fig. 5, for an OOK signal, a chip #1 may refer to a shortest duration of one high voltage and a chip #2 may refer to a shortest duration of one low voltage.
[0085] In some embodiments, a chip duration or chip length may be equal to 1 / M *aduration of a symbol, wherein M represents the number of chips carried on a symbol. For example, for R2D transmission, the chip duration or chip length may be equal to 1 / M *aduration of a symbol. A symbol is an OFDM symbol with 15kHz subcarrier spacing.
[0086] For example, for D2R transmission, a chip corresponds to one modulated symbol at least for OOK and binary phase shift key (BPSK) modulations. The chip duration may be equal to a duration of one modulated symbol at least for OOK and BPSK modulations. For example, the chip duration or chip length may be equal to 1 / (M*15kHz) second.
[0087] It shall be understood that although the definition of the chip is described by taking OOK modulation for example, the definition of the chip may be applied to other Modulation and Coding schemes (MSC) . The scope of the present disclosure is not limited in this regard.
[0088] In some embodiments, the second device 120 may determine the TB size for the R2D transmission based on at least one of the following: the time domain resources associated with the R2D transmission, the size of at least one padding bit or the duration of the at least one padding signal, the information related to the chip duration, the code rate of the line coding, or the code rate of channel coding.
[0089] In some embodiments, for R2D transmission with postamble, the second device 120 may determine the number of symbols for the R2D transmission between preamble and postamble. Hereinafter, the number of symbols for the R2D transmission is represented by Nsym.
[0090] In some embodiments, for R2D transmission without postamble, the first device 110 or the second device 120 may obtain the time domain resources associated with the R2D transmission from the control information.
[0091] In some embodiments, the second device 120 may determine the number of available chips (represented by Nchip) based on the following: Nchip=M·Nsym-Namble-Noverhead (1) where Nsym represents the number of symbols, M represents the number of chips carried on a symbol, Namble represents the number of chips for at least one amble, Noverhead represents the number of chips for other parts, for example, CRC bits. The at least one amble may comprise at least one of the following: preamble, midamble or postamble.
[0092] In some embodiments, the second device 120 may determine unquantized intermediate variable (represented by Ninfo) based at least on the number of available chips (Nchip) , a code rate of channel coding and a code rate of line coding. For example, the second device 120 may determine the unquantized intermediate variable (Ninfo) based on the following: Ninfo=Nchip·Rchannel·Rline (2) where Rchannel represents the code rate of channel coding, and Rline represents the code rate of line coding. For example, the line coding may comprise Manchester coding. If Manchester coding is applied, Rline=0.5.
[0093] In some embodiments, the second device 120 may determine the TB size for the R2D transmission based on the unquantized intermediate variable (Ninfo) and the size of at least one padding bit. For example, the second device 120 may determine the TB size for the R2D transmission based on the following: NTBS=Ninfo-Npadding (3) where NTBS represents the TB size, Npadding represents the number of chips for at least one padding bit. The number of chips for at least one padding bit is equal to the size of at least one padding bit.
[0094] Alternatively, in some embodiments, the second device 120 may determine the number of available chips (Nchip) based on the following: Nchip=M·Nsym-Namble-Noverhead -N′padding (4) where N′padding represents the number of chips for at least one padding. In such embodiments, the second device 120 may determine the TB size for the R2D transmission based on the unquantized intermediate variable (Ninfo) , details of which may refer to TS 38.214 and the details are omitted for brevity. For example, the second device 120 may determine the unquantized intermediate variable (Ninfo) based on the following: Ninfo=Nchip·Rchannel·Rline-N′padding·Rline (5)
[0095] For example, the second device 120 may determine the TB size for the R2D transmission based on the following: NTBS=Ninfo (6)
[0096] In some embodiments, a maximum TB size is around 1000 bits, and a bit width for indicating the TB size is 10 for 1000 bits or 7 for 125 bytes. In other words, NTBS can be as much as 1000 bits with 10-bitwidth indication, but Npadding as the padding for OFDM symbol alignment is in the range of [0, 31] which only requires at most 5 bits. Thus, the bit width for indicating the TB size may be saved by indicating the size of at least one padding bit or the duration of the at least one padding signal.
[0097] In some embodiments, the first device 110 may determine the size of the at least one padding bit or the duration of the at least one padding signal based on the information related to the chip duration (e.g., M) . Alternatively, the first device 110 may determine a size of the indication of the size of the at least one padding bit or the duration of the at least one padding signal based on the information related to the chip duration.
[0098] In some embodiments, a value of M may be in the range of {1, 2, 4, 6, 8, 12, 16, 24, 32} .
[0099] In some embodiments, for M = 1 and 2 with Manchester coding, there is no need for padding, i.e., the size of the indication of the size of the at least one padding bit or the duration of the at least one padding signal is 0. Hereinafter, the indication of the size of the at least one padding bit or the duration of the at least one padding signal is also referred to as “padding bit size indication” , and the size of the indication is also referred to as “padding bit size” for brevity.
[0100] In some embodiments, for M = X with Manchester coding, X ∈ {4, 6, 8, 12, 16, 24, 32} , the size of the indication is equal to log2 (X / 2) . For example, for M = 4, the size of the indication is 1; for M = 6, the size of the indication is 2; for M = 8, the size of the indication is 2; for M =12, the size of the indication is 3; for M = 16, the size of the indication is 3; for M = 24, the size of the indication is 4; for M = 32, the size of the indication is 4. For an applicable case, when X=2, i.e. M=2, log2 (X / 2) =0, that is, the size of the indication is 0.
[0101] In some embodiments, for M = 1 and 2 and pulse interval encoding (PIE) , there is no need for padding, i.e., the size of the indication of the size of the at least one padding bit or the duration of the at least one padding signal is 0.
[0102] In some embodiments, for M = X with PIE, X ε {4, 6, 8, 12, 16, 24, 32} , the size of the indication is equal to log2 (X / 2) . For example, for M = 4, the size of the indication is 1 (PIE with “1” no padding, PIE with “0” with padding bit “0” ) ; for M = 6, the size of the indication is 2; for M = 8, the size of the indication is 2; for M = 12, the size of the indication is 3; for M = 16, the size of the indication is 3; for M = 24, the size of the indication is 4; for M = 32, the size of the indication is 4.
[0103] In some embodiments, for simplicity of padding data, the at least one padding bit is all “0” when PIE is applied to the R2D transmission.
[0104] In some embodiments, without consideration of line coding, for a range of [0, 31] , where 31<25, and 5 bits is enough to indicate all possible cases for the TB size.
[0105] In some embodiments, the value of the indication of the size of the at least one padding bit or the duration of the at least one padding signal may be used to obtain the size of the at least one padding bit or the duration of the at least one padding signal. For example, the value of the indication of the size of the at least one padding bit or the duration of the at least one padding signal may be equal to the size of the at least one padding bit or the duration of the at least one padding signal. For example, a bit size for the value of the indication is 3 and the value of the indication may be “ (010) 2” which corresponds to “ (2) 10” . Thus, the size of the at least one padding bit or the duration of the at least one padding signal is 2, or the duration of the at least one padding signal corresponds to the duration of 2 padding bits.
[0106] In some embodiments, the control information may be in AIoT format 0_1. Table 1 gives an example of AIoT format 0_1. Table 1
[0107] In some embodiments, the first device 110 may insert the at least one padding bit after control information for the R2D transmission. This will be described with reference to Fig. 6.
[0108] Fig. 6 illustrates an example of padding in accordance with some embodiments of the present disclosure. In the example of Fig. 6, padding bits are inserted within the transmission before the CRC attachment, as described with respect to case 1 in Fig. 3A or 3B. As shown in Fig. 6, the padding bits are inserted after control information for the R2D transmission.
[0109] In such embodiments, the first device 110 may determine the size of the at least one padding bit or the duration of the at least one padding signal based on a gap between an end of the R2D transmission without padding and a boundary of an OFDM symbol. In such embodiments, the control information does not comprise the indication of the size of the at least one padding bit or the duration of the at least one padding signal.
[0110] In such embodiments, the first device 110 may determine the gap as the size of the at least one padding bit or the duration of the at least one padding signal. For example, the TB size is indicated or determined first, and the TB size can be used to obtain the number of available chips. Benefits of the at least one padding bit would leave allowance for future release support.
[0111] In some embodiments, the first device 110 may insert the padding bits after control information for the R2D transmission by performing a procedure in Table 2. Table 2
[0112] In some embodiments, the first device 110 may insert padding after the CRC attachment and before the line coding. For example, as shown in Fig. 3A or 3B, in case 2, the first device 110 inserts the padding after the block 310 for the CRC attachment and before the block 320 for the line coding. In such embodiments, on a first symbol, at least one CRC bit is followed by at least one first padding bit. The contents of the at least one first padding bit on the first symbol should ensure no false rising / failing edge is introduced on the first symbol.
[0113] Fig. 7 illustrates an example of false rising edge in accordance with some embodiments of the present disclosure. In the example of Fig. 7, OFDM based OOK waveform for R2D transmission is generated. The following bit to chip mapping for Manchester coding may be as below: a bit 0 is mapped to chips {10} , and a bit 1 is mapped to chips {01} . In order to avoid InterSymbol Interference (ISI) , a cyclic prefix (CP) may be inserted to OFDM based OOK waveform. The CP may be generated by duplicating the contents on the last chip on an OFDM symbol. CP insertion of OFDM based OOK waveform may introduce false rising / failing edge between the last chip on an OFDM symbol (n-1) and the first chip on an OFDM symbol n.
[0114] In some embodiments, if at least one CRC bit is followed by at least one first padding bit on the first symbol, the contents of the at least one first padding bit on the first symbol should ensure no false rising / failing edge is introduced on the first symbol. To this end, if a start CRC bit among the at least one CRC bit is 1, the first device 110 may determine an end padding bit among the at least one first padding bit to be 0. If the start CRC bit is 0, the first device 110 may determine the end padding bit among the at least one first padding bit to be 1. In this way, no false rising / failing edge will be introduced on the first symbol. This will be described with reference to Fig. 8A.
[0115] Fig. 8A illustrates an example of contents of at least one first padding bit in accordance with some embodiments of the present disclosure. In the example of Fig. 8A, Manchester coding is applied, the number (M) of chips on a symbol is equal to 6, and the size of the at least one first padding bit is equal to 2.
[0116] As shown in Fig. 8A, on symbol X, at least one CRC bit is followed by at least one first padding bit. On symbol X, a start CRC bit among the at least one CRC bit is “1” , and the start CRC bit “1” is mapped to chips {01} . Thus, the first device 110 may determine an end padding bit among the at least one first padding bit on symbol X to be “0” . The end padding bit “0” is mapped to chips {10} . In this way, no false rising / failing edge will be introduced.
[0117] In some embodiments, after determining the end padding bit among the at least one first padding bit to be “a” , the first device 110 may determine that all of the at least one first padding bit could be “a” so as to ensure as many edges as possible, where a=0 or 1.
[0118] In some embodiments, the control information may comprise the indication of the size of the at least one first padding bit. The size of the indication or the size of the at least one first padding bit is at most 5 bits for the range of [0, 31] as described above.
[0119] In some embodiments, the control information may be in AIoT format 0_1. Table 3 gives another example of AIoT format 0_1. Table 3
[0120] Alternatively, in some embodiments, the second device 120 may use false edge detection to determine the first symbol, and perform blind detection of CRC to determine the size of the at least one first padding bit on symbol the first symbol.
[0121] In some embodiments, for R2D transmission with postamble, when the postamble does not meet a boundary of a second symbol, additional one or more padding bits are required on the second symbol. The second symbol is subsequent to the first symbol. In such embodiments, the first device 110 may insert at least one second padding bit after the CRC attachment and before the line coding. On the second symbol, the at least one second padding bit is followed by at least part of the postamble. The contents of a start padding bit on the second symbol should ensure no false rising / failing edge is introduced with CP copied from the postamble on the second symbol.
[0122] In some embodiments, in order to ensure no false rising / failing edge is introduced, if an end of the postamble on the second symbol corresponds to a low voltage, the first device 110 may determine a start padding bit among the at least one second padding bit to be 1. If the end of the postamble on the second symbol corresponds to a high voltage, the first device 110 may determine the start padding bit among the at least one second padding bit to be 0. This will be described with reference to Fig. 8B.
[0123] Fig. 8B illustrates an example of contents of at least one second padding bit in accordance with some embodiments of the present disclosure. In the example of Fig. 8B, Manchester coding is applied.
[0124] As shown in Fig. 8B, on symbol X+1, at least one second padding bit is followed by at least part of a postamble. An end of the postamble on symbol X+1 corresponds to a low voltage. Thus, the first device 110 may determine a start padding bit among the at least one second padding bit to be 1. The start padding bit “1” is mapped to chips {01} . In this way, no false rising / failing edge will be introduced.
[0125] In some embodiments, the first device 110 may insert the at least one padding bit by performing a procedure in Table 4. Table 4
[0126] In some embodiments, for R2D transmission, at least one padding bit may be inserted before hopping. This will be described with reference to Fig. 8C.
[0127] Fig. 8C illustrates an example of insertion of at least one padding bit before hopping in accordance with some embodiments of the present disclosure. As shown in Fig. 8C, at least one padding bit is inserted before hopping.
[0128] In some embodiments, for R2D transmission, at least one padding bit may be inserted after hopping. In such embodiments, a duration of the at least one padding bit may be determined based on a time duration for retuning. This will be described with reference to Fig. 8D.
[0129] Fig. 8D illustrates an example of insertion of at least one padding bit after hopping in accordance with some embodiments of the present disclosure. As shown in Fig. 8D, at least one padding bit is inserted after hopping. A duration of the at least one padding bit may be determined based on a time duration for retuning.
[0130] In some embodiments, the first device 110 inserts the padding after the line coding and before OFDM waveform generation for the R2D transmission. For example, as shown in Fig. 3A or 3B, in case 3, the first device 110 inserts the padding after the block 320 for the line coding and before the block 330 for the OFDM waveform generation. In such embodiments, padding no longer needs to follow Manchester coding. In such embodiments, on a third symbol, at least one chip for at least one CRC bit is followed by at least one first padding signal.
[0131] In some embodiments, in order to ensure no false rising / failing edge is introduced, if a start CRC bit among the at least one CRC bit is 1, the first device 110 may determine an end padding signal among the at least one first padding signal to be a low voltage. If the start CRC bit among the at least one CRC bit is 0, the first device 110 may determine the end padding signal among the at least one first padding signal to be a high voltage. This will be described with reference to Fig. 8E.
[0132] Fig. 8E illustrates an example of contents of at least one first padding signal in accordance with some embodiments of the present disclosure. In the example of Fig. 8E, Manchester coding is applied, the number (M) of chips on a symbol is equal to 6.
[0133] As shown in Fig. 8E, on symbol X, at least one chip for at least one CRC bit is followed by at least one first padding signal. On symbol X, a start CRC bit among the at least one CRC bit is “1” , and the start CRC bit “1” is mapped to chips {01} . Thus, the first device 110 may determine an end padding signal (i.e., the last padding signal) among the at least one first padding signal to be a low voltage.
[0134] In some embodiments, after determining the end padding signal among the at least one first padding signal to be “a” , the first device 110 may determine that all of the at least one first padding signal could be “a” , where “a” is a low voltage or high voltage.
[0135] In some embodiments, for R2D transmission with postamble, when the postamble does not meet a boundary of a fourth symbol, additional one or more padding signals are required on the fourth symbol. The fourth symbol is subsequent to the third symbol. In such embodiments, the first device 110 may insert at least one second padding signal after the line coding and before the OFDM waveform generation. On a fourth symbol, at least one second padding signal is followed by at least part of a postamble. The contents of a start padding signal on the fourth symbol should ensure no false rising / failing edge is introduced with CP copied from the postamble on the fourth symbol.
[0136] In some embodiments, in order to ensure no false rising / failing edge is introduced, if an end of the postamble on the fourth symbol corresponds to a low voltage, the first device 110 may determine a start padding signal among the at least one second padding signal to be the low voltage. If the end of the postamble on the second symbol corresponds to a high voltage, the first device 110 may determine the start padding signal among the at least one second padding signal to be the high voltage. This will be described with reference to Fig. 8F.
[0137] Fig. 8F illustrates an example of contents of at least one second padding signal in accordance with some embodiments of the present disclosure.
[0138] As shown in Fig. 8F, on symbol X+1, at least one second padding signal is followed by at least part of a postamble. An end of the postamble on symbol X+1 corresponds to a low voltage. Thus, the first device 110 may determine a start padding signal among the at least one second padding signal to be the low voltage.
[0139] In some embodiments, if the first device 110 inserts the at least one padding signal after the line coding and before OFDM waveform generation for the R2D transmission, the at least one padding signal no longer needs to follow Manchester coding or line coding. In such embodiments, the second device 120 may determine a duration of the at least one padding signal based on blind detection of the at least one padding signal. That is, the second device 120 may detect the signals which do not follow line coding or Manchester coding pattern. This will be described with reference to Fig. 8G.
[0140] Fig. 8G illustrates an example of determining a duration of at least one padding signal in accordance with some embodiments of the present disclosure. In the example of Fig. 8G, Manchester coding is applied.
[0141] As shown in Fig. 8G, padding signals are all low voltages. The second device 120 may determine that a duration of the padding signals are four chips by detecting four continuous low voltages. In this way, the overhead of the indication of the duration of the padding signals can be saved.
[0142] In some embodiments, if the first device 110 inserts the at least one padding signal after the line coding and before OFDM waveform generation for the R2D transmission, the first device 110 may determine a TB size for the R2D transmission by excluding chips for the at least one padding signal. In such embodiments, the first device 110 may determine the number of available chips (Nchip) by excluding chips for the at least one padding signal and determine the TB size based on the number of available chips (Nchip) .
[0143] For example, the first device 110 may determine the number of available chips (Nchip) based on the following: Nchip=M·Nsym-Namble-Noverhead -N′padding where N′padding represents the number of chips for the at least one padding signal.
[0144] In turn, the first device 110 may determine the TB size based on the number of available chips (Nchip) . For example, the first device 110 may determine the TB size based on the equations (5) and (6) as described above.
[0145] In some embodiments, the first device 110 may insert the at least one padding bit by performing a procedure in Table 5. Table 5
[0146] In some embodiments, before inserting the at least one padding signal, the first device 110 may generate the last chip of an output of the line coding, and the output is in short of N′padding signals to the boundary of the OFDM symbol. Then, before or during the OFDM waveform generation, the first device 110 may fill a gap between the last chip of the output of the line coding and the boundary of the OFDM symbol with a predefined sequence. The predefined sequence is the at least one padding signal. In turn, the first device 110 may process them through the OFDM waveform generation.
[0147] In some embodiments, the predefined sequence may be either all “0” or all “1” , or left for implementation of the first device 110.
[0148] In some embodiments, the first device 110 may insert padding after the OFDM waveform generation and before the postamble attachment. For example, as described with respect to case 5 in Fig. 3A, the first device 110 inserts the padding after the block 330 for the OFDM waveform generation and before the block 340 for the postamble attachment. In such embodiments, when the postamble does not end with a boundary of an OFDM symbol, at least one padding signal is required on the OFDM symbol. For example, on a fifth symbol, at least one third padding signal is followed by at least part of a postamble. Such embodiments may ensure the end of the postamble is aligned with a boundary of the fifth symbol. In addition, since the padding signal is on the same symbol as the postamble, the duration of the padding signal can be detected without indication.
[0149] In such embodiments, in order to ensure no false rising / failing edge is introduced with CP copied from the postamble on the fifth symbol, a start padding signal among the at least one third padding signal is the same as an end of the postamble on the fifth symbol. This will be described with reference to Fig. 9A.
[0150] Fig. 9A illustrates an example of contents of at least one third padding signal in accordance with some embodiments of the present disclosure. In the example of Fig. 9A, Manchester coding is applied.
[0151] As shown in Fig. 9A, on the fifth symbol, at least one third padding signal is followed by at least part of a postamble. Because an end of the postamble on the fifth symbol is a low voltage, a start padding signal among the at least one third padding signal is also the low voltage to avoid false rising / failing edge.
[0152] In some embodiments, the first device 110 may insert padding after the postamble attachment. For example, as described with respect to case 6 in Fig. 3A, the first device 110 inserts the padding after the block 340 for the postamble attachment. In such embodiments, when the postamble does not end with a boundary of an OFDM symbol, at least one padding signal is required on the OFDM symbol. For example, on a sixth symbol, at least part of a postamble is followed by at least one fourth padding signal. Such embodiments may ensure the end of the postamble is aligned with a boundary of the sixth symbol. In addition, since the padding signal is on the same symbol as the postamble, the duration of the padding signal can be detected without indication.
[0153] In such embodiments, in order to ensure no false rising / failing edge is introduced with CP copied from the postamble on the sixth symbol, an end padding signal among the at least one fourth padding signal is the same as a start of the postamble on the sixth symbol. This will be described with reference to Fig. 9B.
[0154] Fig. 9B illustrates an example of contents of at least one fourth padding signal in accordance with some embodiments of the present disclosure.
[0155] As shown in Fig. 9B, on the sixth symbol, at least part of a postamble is followed by at least one fourth padding signal. Because a start of the postamble on the sixth symbol is a high voltage, an end padding signal among the at least one fourth padding signal is also the high voltage to avoid false rising / failing edge.
[0156] In some embodiments, if the first device 110 inserts padding after the postamble attachment, padding can be at most 66.7μs (one 15kHz OFDM symbol) , but a gap between R2D transmission and D2R transmission can be as low as 20μs, and padding may cause disorder in timeline.
[0157] In some embodiments, in order to avoid disorder in timeline, a gap between an end of the postamble and a start of D2R transmission is equal to or greater than a larger one of the following: a predefined delay, and a duration of the at least one padding signal.
[0158] For example, Tgap≥Max {Tmin, Tpadding} , where Tgap is the gap between the end of the postamble and the start of D2R transmission, Tmin is a predefined delay (for example, 20μs in RFID) , Tpadding is the duration of the at least one padding signal and Tpadding is at most one symbol duration. Tmin can be used by the second device 120 for processing.
[0159] Alternatively, in some embodiments, in order to avoid disorder in timeline, after detecting the postamble, the second device 120 can obtain the remaining chips on the last symbol (i.e., the duration of the at least one padding signal) , and begins to perform the D2R transmission at least after the end of the at least one padding signal or at least after the end of the at least one padding signal with an additional predefined delay. In such embodiments, the first device 110 begins to monitor the D2R transmission at least after the end of the at least one padding signal or at least after the end of the at least one padding signal with the additional predefined delay. For example, Tgap≥Tmin+Tpadding , where Tmin is the additional predefined delay, and Tpadding is the duration of the at least one padding signal.
[0160] Alternatively, in some embodiments, in order to avoid disorder in timeline, the second device 120 does not perform the D2R transmission before an end of the at least one padding signal or not before the end of the at least one padding signal with an additional predefined delay. In such embodiments, the first device 110 is not expected to receive the D2R transmission before an end of the at least one padding signal or before the end of the at least one padding signal with an additional predefined delay.
[0161] Fig. 9C illustrates an example of contents of at least one padding signal in accordance with some embodiments of the present disclosure.
[0162] As shown in Fig. 9C, on a symbol, at least part of a postamble is followed by at least one padding signal. When the second device 120 detects two chips with “high” voltage, which violate Manchester coding, and determines that postamble is detected, the second device 120 may determine the number of the remaining chips is 4, which is the duration of the at least one padding signal, i.e., Tpadding. The second device 120 should begin the D2R transmission at least after the end of the at least one padding signal or at least after the end of the at least one padding signal with an additional predefined delay.
[0163] In some embodiments, the first device 110 may insert the at least one padding signal by performing a procedure in Table 6. Table 6
[0164] In some embodiments, the first device 110 may insert padding as postamble. In other words, postamble is used to indicate the end of transmission, and padding functions as postamble to indicate the end of transmission.
[0165] In such embodiments, for R2D transmission, a duration of postamble depends the gap between the last chip of an output of line coding and a boundary of an OFDM. This will be described with reference to Figs. 10A, 10B, 10C, 10D and 10E.
[0166] Figs. 10A and 10B illustrate an example of inserting padding as postamble in accordance with some embodiments of the present disclosure, respectively. In the examples of Figs. 10A and 10B, Manchester coding is applied. The last chip of an output of line coding may be Manchester coding of the last bit of CRC bits. Postamble may be a group of chips violating Manchester coding, and a duration of postamble should fulfill a boundary of an OFDM symbol.
[0167] For example, in the example of Fig. 10A, when the second device 120 detects two continuous chips with “high” voltage which violates Manchester coding, and determines postamble is detected, the remaining chips are also counted as postamble with “high” voltage.
[0168] The example of Fig. 10B is different from the example of Fig. 10A in that when the second device 120 detects two continuous chips with “low” voltage which violates Manchester coding, and determines postamble is detected, the remaining chips are also counted as postamble with “low” voltage.
[0169] In some embodiments, the first device 110 may insert the padding as postamble by performing a procedure in Table 7. Table 7
[0170] In some embodiments, if the first device 110 inserts padding as postamble, the first device 110 may determine a duration of postamble based on the information related to the chip duration. The duration of postamble may be in the range of [2, 32] .
[0171] For example, when M=1, the duration of postamble is 2 chips. When M=2, the duration of postamble is 2 chips. When M=4, the duration of postamble is [2, 4] chips. When M=6, the duration of postamble is [2, 6] chips. When M=8, the duration of postamble is [2, 8] chips. When M=12, the duration of postamble is [2, 12] chips. When M=16, the duration of postamble is [2, 16] chips. When M=24, the duration of postamble is [2, 24] chips. When M=32, the duration of postamble is [2, 32] chips.
[0172] In some embodiments, the first device 110 may insert the padding as the postamble by inserting a sequence of all “0” (i.e., low voltage) .
[0173] Alternatively, in some embodiments, the first device 110 may insert the padding as the postamble by inserting a sequence of all “1” (i.e., high voltage) .
[0174] Alternatively, in some embodiments, the first device 110 may insert the padding as the postamble by inserting a repetition of a sequence of “0 0 1 1” or “1 1 0 0” .
[0175] Alternatively, in some embodiments, the first device 110 may insert the padding as the postamble by causing contents on remaining chips for the postamble to be a repetition of contents on a previous chip if the number of the remaining chips is below a threshold. For example, the number of chips for postamble is 6, contents on the first 4 chips for postamble is “1 1 0 0” , and the number of the remaining chips is 2. The threshold is equal to 4. The number of the remaining chips is below the threshold (i.e., 4) . Thus, the contents on the remaining chips is a repetition of “0 0” . Therefore, the postamble may be a sequence of “1 1 0 0 0 0” .
[0176] Alternatively, in some embodiments, the first device 110 may insert the padding as the postamble by inserting a sequence of “1 1” followed by all “0” .
[0177] Alternatively, in some embodiments, the first device 110 may insert the padding as the postamble by inserting K signals, wherein the first K-1 signals among the K signals are “0” and an end signal among the K signals is “1” , or the first K-1 signals are “1” and the end signal is “0” , where K is an integer. For example, K is greater than 2. In such embodiments, “0” means a low voltage signal and “1” means a high voltage signal. In other words, if the number of chips for postamble is greater than 2, contents on an end chip for the postamble is different from contents on the second last chip so as to indicate the end of the postamble. This will be described with reference to Figs. 10C and 10D.
[0178] Figs. 10C and 10D illustrate an example of inserting padding as postamble in accordance with some embodiments of the present disclosure, respectively. In the examples of Figs. 10C and 10D, Manchester coding is applied. The last chip of an output of line coding may be Manchester coding of the last bit of CRC bits. A duration of postamble should fulfill a boundary of an OFDM symbol.
[0179] For example, in the example of Fig. 10C, the postamble may comprise four signals, wherein the first three signals are “1 1 1” and an end signal is “0” . Thus, the postamble may be a sequence of “1 1 1 0” , wherein contents (i.e., “0” ) on the end chip for the postamble is different from contents (i.e., “1” ) on the second last chip so as to indicate the end of the postamble.
[0180] For another example, in the example of Fig. 10D, the postamble may comprise four signals, wherein the first three signals are “0 0 0” and an end signal is “1” . Thus, the postamble may be a sequence of “0 0 0 1” , wherein contents (i.e., “1” ) on the end chip for the postamble is different from contents (i.e., “0” ) on the second last chip.
[0181] For another example, the postamble may comprise sixt signals, wherein the first five signals are “1 1 1 1 1” and an end signal is “0” . Thus, the postamble may be a sequence of “1 1 1 1 1 0” so as to indicate the end of the postamble.
[0182] For a further example, the postamble may comprise sixt signals, wherein the first five signals are “0 0 0 0 0” and an end signal is “1” . Thus, the postamble may be a sequence of “0 0 0 0 0 1” .
[0183] Fig. 10E illustrates an example of inserting padding as postamble in accordance with some embodiments of the present disclosure. In the example of Fig. 10E, Manchester coding is applied. The last chip of an output of line coding may be Manchester coding of the last bit of CRC bits. When the last chip of the output of line coding meets an OFDM symbol boundary, the postamble lasts for at least 2 chips and fills the duration of one or more OFDM symbols. In the example of Fig. 10E, the postamble lasts for 4 chips and fills the duration of one symbol.
[0184] Fig. 11 illustrates a flowchart of an example method 1100 in accordance with some embodiments of the present disclosure. In some embodiments, the method 1100 can be implemented at a device, such as the first device 110 as shown in Fig. 1, 2, 3A or 3B. For the purpose of discussion, the method 1100 will be described with reference to Fig. 1, 2, 3A or 3B as performed by the first device 110 without loss of generality.
[0185] At block 1110, the first device 110 inserts padding within transmission from the first device to the second device 120, before CRC attachment to information bits to be transmitted from the first device, after the CRC attachment and before line coding of the information bits, after the line coding and before OFDM waveform generation for the transmission, during the OFDM waveform generation for the transmission, after the OFDM waveform generation and before postamble attachment to the transmission, after the postamble attachment, or as a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol.
[0186] At block 1120, the first device 110 performs the transmission to the second device 120.
[0187] In some embodiments, inserting padding may comprise: inserting at least one padding bit or at least one padding signal within the transmission.
[0188] In some embodiments, the method 1100 may further comprise: transmitting, to the second device 120, control information for the transmission, wherein the control information comprises an indication of a size of the at least one padding bit or a duration of the at least one padding signal.
[0189] In some embodiments, the method 1100 may further comprise: determining a TB size for the transmission based at least on a size of at least one padding bit or a duration of the at least one padding signal.
[0190] In some embodiments, the method 1100 may further comprise: determining the size of the at least one padding bit or the duration of the at least one padding signal based on information related to a chip duration; or determining a size of the indication based on the information related to the chip duration.
[0191] In some embodiments, insert padding before the CRC attachment may comprise inserting at least one padding bit within the transmission. In such embodiments, insert padding may comprise inserting the at least one padding bit after control information for the transmission. In such embodiments, the method 1100 may further comprise: determining a size of the at least one padding bit based on a gap between an end of the transmission without padding and a boundary of an OFDM symbol.
[0192] In some embodiments, inserting padding may comprise inserting padding after the CRC attachment and before the line coding; and on a first symbol, at least one CRC bit is followed by at least one first padding bit.
[0193] In some embodiments, the method 1100 may further comprise: based on determining that a start CRC bit among the at least one CRC bit is 1, determining an end padding bit among the at least one first padding bit to be 0; and based on determining that the start CRC bit is 0, determining the end padding bit among the at least one first padding bit to be 1.
[0194] In some embodiments, inserting padding may comprise inserting padding after the CRC attachment and before the line coding; and on a second symbol, at least one second padding bit is followed by at least part of a postamble.
[0195] In some embodiments, the method 1100 may further comprise: based on determining that an end of the postamble on the second symbol corresponds to a low voltage, determining a start padding bit among the at least one second padding bit to be 1; and based on determining that the end of the postamble on the second symbol corresponds to a high voltage, determining the start padding bit among the at least one second padding bit to be 0.
[0196] In some embodiments, inserting padding may comprise inserting padding after the line coding and before the OFDM waveform generation; and on a third symbol, at least one chip for at least one CRC bit is followed by at least one first padding signal.
[0197] In some embodiments, inserting padding may comprise inserting the at least one first padding signal by: before or during the OFDM waveform generation, filling a gap between a last chip of an output of the line coding and the boundary of the OFDM symbol with a predefined sequence.
[0198] In some embodiments, the method 1100 may further comprise: based on determining that a start CRC bit among the at least one CRC bit is 1, determining an end padding signal among the at least one first padding signal to be a low voltage; and based on determining that the start CRC bit among the at least one CRC bit is 0, determining the end padding signal among the at least one first padding signal to be a high voltage.
[0199] In some embodiments, the method 1100 may further comprise: based on determining that the end padding signal among the at least one first padding signal is the low voltage, determining all of the at least one first padding signal to be the low voltage; and based on determining that the end padding signal among the at least one first padding signal is the high voltage, determining all of the at least one first padding signal to be the high voltage.
[0200] In some embodiments, the method 1100 may further comprise: determining a TB size for the transmission by excluding chips for the at least one second padding signal.
[0201] In some embodiments, on a fourth symbol, at least one second padding signal is followed by at least part of a postamble.
[0202] In some embodiments, the method 1100 may further comprise: based on determining that an end of the postamble on the fourth symbol corresponds to a low voltage, determining a start padding signal among the at least one second padding signal to be the low voltage; and based on determining that the end of the postamble on the second symbol corresponds to a high voltage, determining the start padding signal among the at least one second padding signal to be the high voltage.
[0203] In some embodiments, the method 1100 may further comprise: determining a TB size for the transmission by excluding chips for the at least one second padding signal.
[0204] In some embodiments, inserting padding may comprise inserting padding after the OFDM waveform generation and before the postamble attachment; and on a fifth symbol, at least one third padding signal is followed by at least part of a postamble; and a start padding signal among the at least one third padding signal is the same as an end of the postamble on the fifth symbol.
[0205] In some embodiments, inserting padding may comprise inserting padding after the postamble attachment; and on a sixth symbol, at least part of a postamble is followed by at least one fourth padding signal; and an end padding signal among the at least one fourth padding signal is the same as a start of the postamble on the sixth symbol.
[0206] In some embodiments, a gap between an end of the postamble and a start of transmission from the second device to the first device is equal to or greater than a larger one of the following: a predefined delay, and a duration of the at least one fourth padding signal.
[0207] In some embodiments, the first device 110 is not expected to receive the transmission from the second device 120 before an end of the at least one fourth padding signal or before the end of the at least one fourth padding signal with an additional predefined delay.
[0208] In some embodiments, the first device 110 begins to monitor the transmission from the second device 120 at least after the end of the at least one fourth padding signal or at least after the end of the at least one fourth padding signal with the additional predefined delay.
[0209] In some embodiments, inserting padding may comprise inserting the padding as the postamble by one of the following: inserting a sequence of all “0” , inserting a sequence of all “1” , inserting a repetition of a sequence of “0 0 1 1” or “1 1 0 0” , causing contents on remaining chips for the postamble to be a repetition of contents on a previous chip if the number of the remaining chips is below a threshold, inserting a sequence of “1 1” followed by all “0” , or inserting K signals, wherein the first K-1 signals are “0” and an end signal is “1” , or the first K-1 signals are “1” and the end signal is “0” , wherein “0” means a low voltage signal and “1” means a high voltage signal, K is an integer.
[0210] Fig. 12 illustrates a flowchart of an example method 1200 in accordance with some embodiments of the present disclosure. In some embodiments, the method 1200 can be implemented at a device, such as the second device 120 as shown in Fig. 1, 2, 3A or 3B. For the purpose of discussion, the method 1200 will be described with reference to Fig. 1, 2, 3A or 3B as performed by the second device 120 without loss of generality.
[0211] At block 1210, the second device 120 receives transmission from the first device 110. Padding is inserted within the transmission, before CRC attachment to information bits to be transmitted from the first device, after the CRC attachment and before line coding of the information bits, after the line coding and before OFDM waveform generation for the transmission, during the OFDM waveform generation for the transmission, after the OFDM waveform generation and before postamble attachment to the transmission, after the postamble attachment, or as a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol.
[0212] Optionally, at block 1220, the second device 120 may process the transmission received from the first device 110. For example, the second device 120 may remove the padding to obtain the information bits.
[0213] In some embodiments, at least one padding bit or at least one padding signal is inserted within the transmission.
[0214] In some embodiments, the method 1200 may further comprise: receiving, from the first device, control information for the transmission, wherein the control information comprises an indication of a size of the at least one padding bit or a duration of the at least one padding signal.
[0215] In some embodiments, the method 1200 may further comprise: determining a TB size for the transmission based at least on a size of the at least one padding bit or a duration of the at least one padding signal.
[0216] In some embodiments, the method 1200 may further comprise: determining the size of the at least one padding bit or the duration of the at least one padding signal based on information related to a chip duration.
[0217] In some embodiments, at least one padding bit is inserted within the transmission before the CRC attachment; the at least one padding bit is inserted after control information for the transmission; and the method 1200 may further comprise: determining a size of the at least one padding bit based on a gap between an end of the transmission without padding and a boundary of an OFDM symbol.
[0218] In some embodiments, padding is inserted after the CRC attachment and before the line coding; and on a first symbol, at least one CRC bit is followed by at least one first padding bit.
[0219] In some embodiments, the method 1200 may further comprise: based on determining that a start CRC bit among the at least one CRC bit is 1, determining an end padding bit among the at least one first padding bit to be 0; and based on determining that the start CRC bit is 0, determining the end padding bit among the at least one first padding bit to be 1.
[0220] In some embodiments, padding is inserted after the CRC attachment and before the line coding; and on a second symbol, at least one second padding bit is followed by at least part of a postamble.
[0221] In some embodiments, the method 1200 may further comprise: based on determining that an end of the postamble on the second symbol corresponds to a low voltage, determining a start padding bit among the at least one second padding bit to be 1; and based on determining that the end of the postamble on the second symbol corresponds to a high voltage, determining the start padding bit among the at least one second padding bit to be 0.
[0222] In some embodiments, padding is inserted after the line coding and before the OFDM waveform generation; and on a third symbol, at least one chip for at least one CRC bit is followed by at least one first padding signal.
[0223] In some embodiments, before or during the OFDM waveform generation, a gap between a last chip of an output of the line coding and the boundary of the OFDM symbol is filled with a predefined sequence.
[0224] In some embodiments, the method 1200 may further comprise: based on determining that a start CRC bit among the at least one CRC bit is 1, determining an end padding signal among the at least one first padding signal to be a low voltage; and based on determining that the start CRC bit among the at least one CRC bit is 0, determining the end padding signal among the at least one first padding signal to be a high voltage.
[0225] In some embodiments, the method 1200 may further comprise: based on determining that the end padding signal among the at least one first padding signal is the low voltage, determining all of the at least one first padding signal to be the low voltage; and based on determining that the end padding signal among the at least one first padding signal is the high voltage, determining all of the at least one first padding signal to be the high voltage.
[0226] In some embodiments, at least one padding signal is inserted after the line coding and before the OFDM waveform generation. In such embodiments, the method 1200 may further comprise: determining a TB size for the transmission by excluding chips for the at least one padding signal.
[0227] In some embodiments, on a fourth symbol, at least one second padding signal is followed by at least part of a postamble.
[0228] In some embodiments, the method 1200 may further comprise: based on determining that an end of the postamble on the fourth symbol corresponds to a low voltage, determining a start padding signal among the at least one second padding signal to be the low voltage; and based on determining that the end of the postamble on the second symbol corresponds to a high voltage, determining the start padding signal among the at least one second padding signal to be the high voltage.
[0229] In some embodiments, the method 1200 may further comprise: determining a TB size for the transmission by excluding chips for the at least one second padding signal.
[0230] In some embodiments, the method 1200 may further comprise: determining a duration of at least one padding signal based on blind detection of the at least one padding signal.
[0231] In some embodiments, padding is inserted after the OFDM waveform generation and before the postamble attachment; on a fifth symbol, at least one third padding signal is followed by at least part of a postamble; and a start padding signal among the at least one third padding signal is the same as an end of the postamble on the fifth symbol.
[0232] In some embodiments, padding is inserted after the postamble attachment; on a sixth symbol, at least part of a postamble is followed by at least one fourth padding signal; and an end padding signal among the at least one fourth padding signal is the same as a start of the postamble on the sixth symbol.
[0233] In some embodiments, the method 1200 may further comprise: after receiving the transmission from the first device 110, performing transmission to the first device 110. In some embodiments, a gap between an end of the postamble and a start of the transmission to the first device is equal to or greater than a larger one of the following: a predefined delay, and a length of the at least one fourth padding signal.
[0234] In some embodiments, the transmission to the first device is not before an end of the at least one fourth padding signal or not before the end of the at least one fourth padding signal with an additional predefined delay.
[0235] In some embodiments, the second device begins to perform the transmission to the first device at least after the end of the at least one fourth padding signal or at least after the end of the at least one fourth padding signal with the additional predefined delay.
[0236] In some embodiments, the padding is inserted as the postamble by one of the following: inserting a sequence of all “0” , inserting a sequence of all “1” , inserting a repetition of a sequence of “0 0 1 1” or “1 1 0 0” , causing contents on remaining chips for the postamble to be a repetition of contents on a previous chip if the number of the remaining chips is below a threshold, inserting a sequence of “1 1” followed by all “0” , or inserting K signals, wherein the first K-1 signals are “0” and an end signal is “1” , or the first K-1 signals are “1” and the end signal is “0” . In such embodiments, “0” means a low voltage signal and “1” means a high voltage signal, K is an integer.
[0237] It shall be noted that implementations of the present disclosure which have been described with reference to Figs. 1 to 10B are also applicable to the methods 1100 and 1200.
[0238] Fig. 13 is a simplified block diagram of a device 1300 that is suitable for implementing embodiments of the present disclosure. The device 1300 can be considered as a further example embodiment of the first device 110 or the second device 120 as shown in Fig. 1, 2, 3A or 3B. Accordingly, the device 1300 can be implemented at or as at least a part of the first device 110 or the second device 120.
[0239] As shown, the device 1300 includes a processor 1310, a memory 1320 coupled to the processor 1310, a suitable transceiver 1340 coupled to the processor 1310, and a communication interface coupled to the transceiver 1340. The memory 1310 stores at least a part of a program 1330. The transceiver 1340 may be for bidirectional communications or a unidirectional communication based on requirements. The transceiver 1340 may include at least one of a transmitter 1342 and a receiver 1344. The transmitter 1342 and the receiver 1344 may be functional modules or physical entities. The transceiver 1340 has at least one antenna to facilitate communication, though in practice an Access Node mentioned in this application may have several ones. The communication interface may represent any interface that is necessary for communication with other network elements, such as X2 / Xn interface for bidirectional communications between eNBs / gNBs, S1 / NG interface for communication between a Mobility Management Entity (MME) / Access and Mobility Management Function (AMF) / SGW / UPF and the eNB / gNB, Un interface for communication between the eNB / gNB and a relay node (RN) , or Uu interface for communication between the eNB / gNB and a terminal device.
[0240] The components included in the apparatuses and / or devices of the present disclosure may be implemented in various manners, including software, hardware, firmware, or any combination thereof. In one embodiment, one or more units may be implemented using software and / or firmware, for example, machine-executable instructions stored on the storage medium. In addition to or instead of machine-executable instructions, parts or all of the units in the apparatuses and / or devices may be implemented, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs) , Application-specific Integrated Circuits (ASICs) , Application-specific Standard Products (ASSPs) , System-on-a-chip systems (SOCs) , Complex Programmable Logic Devices (CPLDs) , and the like.
Claims
1.A first device, comprising:a processor configured to cause the first device to:insert padding within transmission from the first device to a second device,before cyclic redundancy check (CRC) attachment to information bits to be transmitted from the first device,after the CRC attachment and before line coding of the information bits,after the line coding and before orthogonal frequency division multiplexing (OFDM) waveform generation for the transmission,during the OFDM waveform generation for the transmission,after the OFDM waveform generation and before postamble attachment to the transmission,after the postamble attachment, oras a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol; andperform the transmission to the second device.2.The first device of claim 1, wherein the first device is caused to insert padding by:inserting at least one padding bit or at least one padding signal within the transmission.3.The first device of claim 2, wherein the first device is further caused to:transmit, to the second device, control information for the transmission, wherein the control information comprises an indication of a size of the at least one padding bit or a duration of the at least one padding signal.4.The first device of claim 2, wherein the first device is further caused to:determine a transport block (TB) size for the transmission based at least on a size of at least one padding bit or a duration of the at least one padding signal.5.The first device of claim 3, wherein the first device is further caused to:determine the size of the at least one padding bit or the duration of the at least one padding signal based on information related to a chip duration; ordetermine a size of the indication based on the information related to the chip duration.6.The first device of claim 1, wherein the first device is caused to insert padding before the CRC attachment by inserting at least one padding bit within the transmission;wherein the first device is caused to insert the at least one padding bit after control information for the transmission; andwherein the first device is further caused to:determine a size of the at least one padding bit based on a gap between an end of the transmission without padding and a boundary of an OFDM symbol.7.The first device of claim 2, wherein the first device is caused to insert padding after the CRC attachment and before the line coding; andwherein on a first symbol, at least one CRC bit is followed by at least one first padding bit.8.The first device of claim 7, wherein the first device is further caused to:based on determining that a start CRC bit among the at least one CRC bit is 1, determine an end padding bit among the at least one first padding bit to be 0; andbased on determining that the start CRC bit is 0, determine the end padding bit among the at least one first padding bit to be 1.9.The first device of claim 7, wherein the first device is caused to insert padding after the CRC attachment and before the line coding; andwherein on a second symbol, at least one second padding bit is followed by at least part of a postamble.10.The first device of claim 9, wherein the first device is further caused to:based on determining that an end of the postamble on the second symbol corresponds to a low voltage, determine a start padding bit among the at least one second padding bit to be 1; andbased on determining that the end of the postamble on the second symbol corresponds to a high voltage, determine the start padding bit among the at least one second padding bit to be 0.11.The first device of claim 1, wherein the first device is caused to insert padding after the line coding and before the OFDM waveform generation; andwherein on a third symbol, at least one chip for at least one CRC bit is followed by at least one first padding signal.12.The first device of claim 11, wherein the first device is caused to insert the at least one first padding signal by:before or during the OFDM waveform generation, filling a gap between a last chip of an output of the line coding and the boundary of the OFDM symbol with a predefined sequence.13.The first device of claim 11, wherein the first device is further caused to:based on determining that a start CRC bit among the at least one CRC bit is 1, determine an end padding signal among the at least one first padding signal to be a low voltage; andbased on determining that the start CRC bit among the at least one CRC bit is 0, determine the end padding signal among the at least one first padding signal to be a high voltage.14.The first device of claim 13, wherein the first device is further caused to:based on determining that the end padding signal among the at least one first padding signal is the low voltage, determine all of the at least one first padding signal to be the low voltage; andbased on determining that the end padding signal among the at least one first padding signal is the high voltage, determine all of the at least one first padding signal to be the high voltage.15.The first device of claim 11, wherein the first device is further caused to:determine a transport block (TB) size for the transmission by excluding chips for the at least one second padding signal.16.The first device of claim 11, wherein on a fourth symbol, at least one second padding signal is followed by at least part of a postamble.17.The first device of claim 16, wherein the first device is further caused to:based on determining that an end of the postamble on the fourth symbol corresponds to a low voltage, determine a start padding signal among the at least one second padding signal to be the low voltage; andbased on determining that the end of the postamble on the second symbol corresponds to a high voltage, determine the start padding signal among the at least one second padding signal to be the high voltage.18.The first device of claim 16, wherein the first device is further caused to:determine a transport block (TB) size for the transmission by excluding chips for the at least one second padding signal.19.The first device of claim 1, wherein the first device is caused to insert padding after the OFDM waveform generation and before the postamble attachment; andwherein on a fifth symbol, at least one third padding signal is followed by at least part of a postamble; andwherein a start padding signal among the at least one third padding signal is the same as an end of the postamble on the fifth symbol.20.The first device of claim 1, wherein the first device is caused to insert padding after the postamble attachment; andwherein on a sixth symbol, at least part of a postamble is followed by at least one fourth padding signal; andwherein an end padding signal among the at least one fourth padding signal is the same as a start of the postamble on the sixth symbol.21.The first device of claim 1, wherein a gap between an end of the postamble and a start of transmission from the second device to the first device is equal to or greater than a larger one of the following: a predefined delay, and a duration of the at least one fourth padding signal; orwherein the first device is not expected to receive the transmission from the second device before an end of the at least one fourth padding signal or before the end of the at least one fourth padding signal with an additional predefined delay; orwherein the first device begins to monitor the transmission from the second device at least after the end of the at least one fourth padding signal or at least after the end of the at least one fourth padding signal with the additional predefined delay.22.The first device of claim 1, wherein the first device is caused to insert the padding as the postamble by one of the following:inserting a sequence of all “0” ,inserting a sequence of all “1” ,inserting a repetition of a sequence of “0 0 1 1” or “1 1 0 0” ,causing contents on remaining chips for the postamble to be a repetition of contents on a previous chip if the number of the remaining chips is below a threshold,inserting a sequence of “1 1” followed by all “0” , orinserting K signals, wherein the first K-1 signals are “0” and an end signal is “1” , or the first K-1 signals are “1” and the end signal is “0” , wherein “0” means a low voltage signal and “1” means a high voltage signal, K is an integer.23.A second device, comprising:a processor configured to cause the second device to:receive transmission from a first device, wherein padding is inserted within the transmission,before cyclic redundancy check (CRC) attachment to information bits to be transmitted from the first device,after the CRC attachment and before line coding of the information bits,after the line coding and before orthogonal frequency division multiplexing (OFDM) waveform generation for the transmission,during the OFDM waveform generation for the transmission,after the OFDM waveform generation and before postamble attachment to the transmission,after the postamble attachment, oras a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol.24.The second device of claim 23, wherein at least one padding bit or at least one padding signal is inserted within the transmission.25.The second device of claim 24, wherein the second device is further caused to:receive, from the first device, control information for the transmission, wherein the control information comprises an indication of a size of the at least one padding bit or a duration of the at least one padding signal.26.The second device of claim 24, wherein the second device is further caused to:determine a transport block (TB) size for the transmission based at least on a size of the at least one padding bit or a duration of the at least one padding signal.27.The second device of claim 25, wherein the second device is further caused to:determine the size of the at least one padding bit or the duration of the at least one padding signal based on information related to a chip duration.28.The second device of claim 23, wherein at least one padding bit is inserted within the transmission before the CRC attachment;wherein the at least one padding bit is inserted after control information for the transmission; andwherein the second device is further caused to:determine a size of the at least one padding bit based on a gap between an end of the transmission without padding and a boundary of an OFDM symbol.29.The second device of claim 23, wherein before or during the OFDM waveform generation, a gap between a last chip of an output of the line coding and the boundary of the OFDM symbol is filled with a predefined sequence.30.The second device of claim 23, wherein at least one padding signal is inserted after the line coding and before the OFDM waveform generation; andwherein the second device is further caused to:determine a transport block (TB) size for the transmission by excluding chips for the at least one padding signal.31.The second device of claim 23, wherein the second device is further caused to:determine a duration of at least one padding signal based on blind detection of the at least one padding signal.32.The second device of claim 23, wherein padding is inserted after the OFDM waveform generation and before the postamble attachment;wherein on a fifth symbol, at least one third padding signal is followed by at least part of a postamble; andwherein a start padding signal among the at least one third padding signal is the same as an end of the postamble on the fifth symbol.33.The second device of claim 23, wherein padding is inserted after the postamble attachment;wherein on a sixth symbol, at least part of a postamble is followed by at least one fourth padding signal; andwherein an end padding signal among the at least one fourth padding signal is the same as a start of the postamble on the sixth symbol.34.The second device of claim 23, wherein the second device is further caused to:after receiving the transmission from the first device, perform transmission to the first device; andwherein a gap between an end of the postamble and a start of the transmission to the first device is equal to or greater than a larger one of the following: a predefined delay, and a length of the at least one fourth padding signal; orwherein the transmission to the first device is not before an end of the at least one fourth padding signal or not before the end of the at least one fourth padding signal with an additional predefined delay; orwherein the second device begins to perform the transmission to the first device at least after the end of the at least one fourth padding signal or at least after the end of the at least one fourth padding signal with the additional predefined delay.35.The second device of claim 23, wherein the padding is inserted as the postamble by one of the following:inserting a sequence of all “0” ,inserting a sequence of all “1” ,inserting a repetition of a sequence of “0 0 1 1” or “1 1 0 0” ,causing contents on remaining chips for the postamble to be a repetition of contents on a previous chip if the number of the remaining chips is below a threshold,inserting a sequence of “1 1” followed by all “0” , orinserting K signals, wherein the first K-1 signals are “0” and an end signal is “1” , or the first K-1 signals are “1” and the end signal is “0” , wherein “0” means a low voltage signal and “1” means a high voltage signal, K is an integer.36.A method for communication, comprising:inserting, at a first device, padding within transmission from the first device to a second device,before cyclic redundancy check (CRC) attachment to information bits to be transmitted from the first device,after the CRC attachment and before line coding of the information bits,after the line coding and before orthogonal frequency division multiplexing (OFDM) waveform generation for the transmission,during the OFDM waveform generation for the transmission,after the OFDM waveform generation and before postamble attachment to the transmission,after the postamble attachment, oras a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol; andperforming the transmission to the second device.37.A method for communication, comprising:receiving transmission at a second device from a first device, wherein padding is inserted within the transmission,before cyclic redundancy check (CRC) attachment to information bits to be transmitted from the first device,after the CRC attachment and before line coding of the information bits,after the line coding and before orthogonal frequency division multiplexing (OFDM) waveform generation for the transmission,during the OFDM waveform generation for the transmission,after the OFDM waveform generation and before postamble attachment to the transmission,after the postamble attachment, oras a postamble by filling a gap between a last chip of an output of the line coding and a boundary of an OFDM symbol.