WO2009022817A1 - Système de communication à multiplexage temporel à structure parallèle, et procédé correspondant - Google Patents

Système de communication à multiplexage temporel à structure parallèle, et procédé correspondant Download PDF

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Publication number
WO2009022817A1
WO2009022817A1 PCT/KR2008/004615 KR2008004615W WO2009022817A1 WO 2009022817 A1 WO2009022817 A1 WO 2009022817A1 KR 2008004615 W KR2008004615 W KR 2008004615W WO 2009022817 A1 WO2009022817 A1 WO 2009022817A1
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WIPO (PCT)
Prior art keywords
signals
time division
transmission
parallel signals
parallel
Prior art date
Application number
PCT/KR2008/004615
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English (en)
Inventor
Woo Yong Lee
Kyeongpyo Kim
Jin Kyeong Kim
Yong Sun Kim
Hyoung Jin Kwon
Original Assignee
Electronics And Telecommunications Research Institute
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020080075658A external-priority patent/KR101454027B1/ko
Application filed by Electronics And Telecommunications Research Institute filed Critical Electronics And Telecommunications Research Institute
Priority to US12/672,735 priority Critical patent/US8406259B2/en
Publication of WO2009022817A1 publication Critical patent/WO2009022817A1/fr

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Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B7/00Radio transmission systems, i.e. using radiation field
    • H04B7/24Radio transmission systems, i.e. using radiation field for communication between two or more posts
    • H04B7/26Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
    • H04B7/2643Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using time-division multiple access [TDMA]
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00Arrangements for detecting or preventing errors in the information received
    • H04L1/0001Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0002Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/26Systems using multi-frequency codes
    • H04L27/2601Multicarrier modulation systems
    • H04L27/2626Arrangements specific to the transmitter only
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/26Systems using multi-frequency codes
    • H04L27/2601Multicarrier modulation systems
    • H04L27/2647Arrangements specific to the receiver only
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/26Systems using multi-frequency codes
    • H04L27/2601Multicarrier modulation systems
    • H04L27/2614Peak power aspects

Definitions

  • the present invention relates to a communication system and a method for the same, and more particularly, a time division multiplexing communication system with a parallel structure and a method for the same.
  • an Orthogonal Frequency Division Multiplexing (OFDM) scheme or an Orthogonal Frequency Division Multiple Access (OFDMA) scheme known as useful schemes for high-speed data transmission in wired/wireless channels may transmit data using a plurality of carriers, and more specifically, may convert data inputted in serial into data in parallel, modulate the converted data into a plurality of subcarriers having mutual orthogonality with respect to each of the converted data, that is, sub-channels, and transmit the modulated data.
  • OFDM Orthogonal Frequency Division Multiplexing
  • OFDMA Orthogonal Frequency Division Multiple Access
  • the above-mentioned OFDM scheme may transmit data while maintaining orthogonality between the plurality of subcarriers, and thus obtaining optimum transmission efficiency at the time of high-speed data transmission, and also obtaining multi-path fading tolerance characteristics and superior frequency efficiency.
  • the OFDM scheme may superimpose one frequency spectrum over another, and thus reducing interference effects between symbols using a guard zone tolerating frequency selective fading, simply designing a structure of an equalizer in hardware, and tolerating impulse noise.
  • a conventional OFDM system having a single flow type structure may change a magnitude of a fast Fourier transform (FFT) to adjust a transmission speed
  • a conventional OFDM system having a parallel flow type structure may parallelize only partially encoded and decoded parts or a Radio Frequency (RF) front- end, each which results in reduction in an operation speed of all hardware in a high speed system.
  • FFT fast Fourier transform
  • RF Radio Frequency
  • An aspect of the present invention provides a time division multiplexing communication system and a method for the same in which a number of parallel streams may be variably adjusted according to channel related-information such as a channel state, a frequency bandwidth, a transmission rate, a Signal-to-Noise Ratio (SNR), and the like in a high-speed radio communication system, so that an internal operation speed of the system, thereby increasing an amount of data that can be processed simultaneously.
  • channel related-information such as a channel state, a frequency bandwidth, a transmission rate, a Signal-to-Noise Ratio (SNR), and the like in a high-speed radio communication system, so that an internal operation speed of the system, thereby increasing an amount of data that can be processed simultaneously.
  • SNR Signal-to-Noise Ratio
  • An aspect of the present invention provides a time division multiplexing communication system and a method for the same in which a multiplexing ratio is reduced simultaneously in a case of applications requiring a low transmission rate, so that an amount of data that can be processed is reduced, thereby reducing power consumed in the system.
  • An aspect of the present invention provides a time division multiplexing communication system and a method for the same in which a frequency bandwidth is reduced by reducing a multiplexing ratio in a case of a poor channel state, so that data is transmitted while avoiding bands where a deep fading from among assigned frequency bands exists, thereby increasing efficiency and reliability of the communication.
  • An aspect of the present invention provides a time division multiplexing communication system and a method for the same which may be applicable in an Orthogonal Frequency Division Multiplexing (OFDM) system, thereby reducing a Peak to Average Power Ratio (PAPR).
  • An aspect of the present invention provides a time division multiplexing communication system and a method for the same in which Bit Error Rate (BER) performance is improved through a time diversity gain, and a transmission distance is enlarged.
  • BER Bit Error Rate
  • a transmission apparatus of a Time Division Multiplexing communication system with a parallel structure including: a Time Division Demultiplexer (TDDM) to perform time division demultiplexing of inputted first serial signals to thereby output the demultiplexed serial signals as a plurality of parallel signals; a plurality of modulators to respectively modulate the outputted parallel signals; a Time Division Multiplexer (TDM) to adjust a multiplexing ratio according to channel-related information, and to perform time division multiplexing of each of the modulated parallel signals in the adjusted multiplexing ratio to thereby output the multiplexed parallel signals as second serial signals; and a transmission antenna to transmit the outputted second serial signals.
  • the TDM may adjust a time diversity gain according to the channel-related information, and adjust the multiplexing ratio according to the adjusted time diversity gain.
  • the TDM may compare a time diversity gain with a maximum time diversity gain when the time diversity gain is requested from a receiving apparatus, determine a number of the parallel signals to correspond to the maximum time diversity gain based on the compared result, and perform time division multiplexing of the determined number of parallel signals.
  • the TDM may compare, with a maximum transmission ratio, a transmission ratio of the requested transmission rate to another transmission rate for each of the parallel signals, determine a number of the parallel signals to correspond to the transmission ratio based on the compared result, and perform time division multiplexing of the determined number of parallel signals.
  • the TDM may compare, with a maximum time diversity gain, the sum of a transmission ratio of the requested transmission rate to another transmission rate for each of the parallel signals and the requested time diversity, determine a number of the parallel signals to correspond to the maximum time diversity gain based on the compared result, and perform time division multiplexing of the determined number of parallel signals.
  • a receiving apparatus of a Time Division Multiplexing communication system with a parallel structure including: a receiving antenna to receive second serial signals from a transmission apparatus; a Time Division Demultiplexer (TDDM) to perform time division demultiplexing of the received second serial signals in a demultiplexing ratio corresponding to a multiplexing ratio of the transmission apparatus to thereby output the demultiplexed serial signals as a plurality of parallel signals; a plurality of demodulators to respectively demodulate the outputted parallel signals; and a Time Division Multiplexer (TDM) to perform time division multiplexing of each of the demodulated parallel signals to thereby restore the multiplexed parallel signals as a first serial signal.
  • TDDM Time Division Demultiplexer
  • TDM Time Division Multiplexer
  • the transmission apparatus may perform time division demultiplexing of inputted first serial signals to thereby output the demultiplexed serial signals as a plurality of parallel signals, perform time division multiplexing of each of the outputted parallel signals in a multiplexing ratio depending on channel related- information to thereby output the multiplexed parallel signals as second serial signals, and transmit the outputted second serial signals.
  • a transmission method of a time division multiplexing communication system with a parallel structure including: performing time division demultiplexing of inputted first serial signals to thereby output the demultiplexed serial signals as a plurality of parallel signals; modulating each of the outputted parallel signals; adjusting a multiplexing ratio according to a channel state and a frequency bandwidth, and performing time division multiplexing of each of the plurality of the demodulated parallel signals to thereby output the multiplexed parallel signals as second serial signals; and transmitting the outputted second serial signals.
  • the performing of the time division multiplexing may include adjusting a time diversity gain according to channel related information; and adjusting the multiplexing ratio according to the adjusted time diversity gain.
  • the performing of the time division multiplexing may include: comparing a time diversity gain with a maximum time diversity gain when the time diversity gain is requested from a receiving apparatus; determining a number of the parallel signals to correspond to the maximum time diversity gain based on the compared result; and performing time division multiplexing of the determined number of parallel signals.
  • the performing of the time division multiplexing may include: comparing, with a maximum transmission ratio, a transmission ratio of a transmission rate to another transmission rate for each of the parallel signals when assignment of the transmission rate or bandwidth is requested from a receiving apparatus; determining a number of the parallel signals to correspond to the transmission rate based on the compared result; and performing time division multiplexing of the determined number of parallel signals.
  • the performing of the time division multiplexing may include: comparing, with a maximum time diversity gain, the sum of a transmission ratio of a transmission rate to another transmission rate for each of the parallel signals and time diversity gain when assignment of the transmission rate or bandwidth, and the time diversity gain are requested from a receiving apparatus; determining a number of the parallel signals to correspond to the maximum time diversity gain based on the compared result; and performing time division multiplexing of the determined number of parallel signals.
  • a receiving method of a time division multiplexing communication system with a parallel structure including: receiving second serial signals from a transmission apparatus; performing time division demultiplexing of the received second serial signals in a demultiplexing ratio corresponding to a multiplexing ratio of the transmission apparatus to thereby output the demultiplexed serial signals as a plurality of parallel signals; respectively demodulating the outputted parallel signals; and performing time division multiplexing of each of the demodulated parallel signals as first serial signals.
  • a number of parallel streams may be variably adjusted according to channel related-information such as a channel state, a frequency bandwidth, a transmission rate, a Signal-to-Noise Ratio (SNR), and the like in a high-speed radio communication system, so that an internal operation speed of the system, thereby increasing an amount of data that can be processed simultaneously.
  • channel related-information such as a channel state, a frequency bandwidth, a transmission rate, a Signal-to-Noise Ratio (SNR), and the like in a high-speed radio communication system, so that an internal operation speed of the system, thereby increasing an amount of data that can be processed simultaneously.
  • SNR Signal-to-Noise Ratio
  • a multiplexing ratio is reduced simultaneously in a case of applications requiring a low transmission rate, so that an amount of data that can be processed is reduced, thereby reducing power consumed in the system.
  • a frequency bandwidth is reduced by reducing a multiplexing ratio in a case of poor channel state, so that data is transmitted while avoiding bands where a deep fading from among assigned frequency bands exists, thereby increasing efficiency and reliability of the communication.
  • the present invention is applicable in an Orthogonal Frequency Division Multiplexing (OFDM) system, thereby reducing a Peak to Average Power Ratio (PAPR).
  • OFDM Orthogonal Frequency Division Multiplexing
  • PAPR Peak to Average Power Ratio
  • Bit Error Rate (BER) performance is improved through a time diversity gain, and a transmission distance is enlarged.
  • FIG. 1 is a block diagram illustrating a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention
  • FIG. 2 is a block diagram illustrating a transmission apparatus of a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention
  • FIG. 3 is a block diagram illustrating a receiving apparatus of a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention
  • FIG. 5 is a flowchart illustrating a transmission method of a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention
  • FIG. 6 is a flowchart illustrating a receiving method of a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention
  • FIG. 11 illustrates an example of a transmission apparatus of an Orthogonal Frequency Division Multiplexing (OFDM) system adopting a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention
  • OFDM Orthogonal Frequency Division Multiplexing
  • FIG. 12 illustrates an example of a receiving apparatus of an OFDM system adopting a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention
  • FIG. 1 is a block diagram illustrating a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention.
  • the time division multiplexing communication system may include a transmission apparatus 110 and a receiving apparatus 120.
  • the transmission apparatus 110 performs time division demultiplexing of inputted first serial signals to thereby output the demulitplexed signals as a plurality of parallel signals, and performs time division multiplexing of each of the outputted parallel signals in a multiplexing ratio according to channel related information to thereby output the multiplexed parallel signals as second serial signals. Also, the transmission apparatus 110 may transmit the outputted second serial signals to the receiving apparatus 120.
  • the receiving apparatus 120 may receive the second serial signals from the transmission apparatus HOk, and perform time division demultiplexing of the received second serial signals in a demultiplexing ratio corresponding to a multiplexing ratio of the transmission apparatus to thereby output the demultiplexed serial signals as a plurality of parallel signals. Also, the receiving apparatus 120 may perform time division multiplexing of each of the outputted parallel signals to thereby restore the multiplexed parallel signals as first serial signals.
  • FIG. 2 is a block diagram illustrating a transmission apparatus of a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention.
  • the transmission apparatus 110 may include a Time Division DeMultiplexer (TDDM) 210, a plurality of channel encoders 220, a plurality of modulators 230, a Time Division Multiplexer (TDM) 240, an upconverter 250, and a transmission antenna 260.
  • TDDM Time Division DeMultiplexer
  • TDM Time Division Multiplexer
  • the TDDM 210 may receive an input of first serial signals, and perform time division demultiplexing of the inputted first serial signals to thereby output the demultiplexed serial signals as a plurality of parallel signals.
  • the TDDM may receive an input of first serial signals, and perform time division demultiplexing of the inputted first serial signals to thereby output the demultiplexed serial signals as a plurality of parallel signals.
  • the TDDM may perform time division demultiplexing of the inputted first serial signals to thereby output the demultiplexed serial signals as a plurality of parallel signals.
  • 210 may parallelize the first serial signals received in serial and divide by space to thereby output as a plurality of parallel signals.
  • the plurality of channel encoders 220 may respectively encode the outputted parallel signals. Specifically, the plurality of channel encoders 220 may convert each of the outputted parallel signals into digital signals to output.
  • the plurality of modulators 230 may modulate each of the encoded parallel signals.
  • the plurality of modulators 230 may modulate each of the encoded parallel signals according to a determined modulation scheme.
  • the modulation scheme may include a Frequency Shift Keying (FSK), Amplitude Shift Keying (ASK), Phase Shift Keying (PSK), Quadrature Amplitude Modulation (QAM), and the like.
  • the TDM 240 may perform time division multiplexing of each of the modulated parallel signals in the adjusted multiplexing ratio to thereby output the multiplexed parallel signals as second serial signals. Specifically, the TDM 240 may perform time division multiplexing of the adjusted number of parallel flow (parallel signals) in a multiplexing ratio adjusted according to the channel related information to thereby output the multiplexed parallel signals as the second serial signals.
  • the TDM 240 may adjust a time diversity gain according to the channel related-information, and adjust the multiplexing ratio according to the adjusted time diversity gain.
  • the TDM 240 may increase an amount of data that can be processed simultaneously by increasing the multiplexing ratio in a case of the receiving apparatus 120 requesting a high transmission rate, and reduce the amount of data by reducing the multiplexing ratio in a case of the receiving apparatus 120 requesting a low transmission rate.
  • the TDM 240 may perform time division multiplexing of each of the modulated parallel signals based on the multiplexing ratio depending on the channel related-information, thereby variably adjusting the transmission rate.
  • the TDM 240 may reduce a frequency bandwidth by reducing the multiplexing ratio in a case of poor channel state, thereby transmitting data while avoiding a band where deep fading exists from among assigned frequency bands. As a result, the TDM 240 may increase efficiency and reliability of communication.
  • the TDM 240 may adjust an amount of data transmission according to a request transmission rate from the receiving apparatus 120, thereby adjusting power consumption. Also, the TDM 240 may adjust the frequency bandwidth by adjusting the multiplexing ratio according to a channel state, thereby effectively using the frequency band, and enabling reliable communication to be performed.
  • the process for the time diversity gain may be divided into a case of being requested from the receiving apparatus 120, and a case of being requested assignment of the transmission rate or a bandwidth.
  • the TDM 240 may compare the requested time diversity gain with a maximum time diversity gain. Also, the TDM 240 may determine a number of the parallels signals to correspond to the maximum time diversity gain based on the compared result, and perform time division multiplexing the determined number of parallel signals. Specifically, the TDM 240 may compare a time diversity gain ' and a maximum time diversity gain K when the time diversity gain ' is requested from the receiving apparatus 120. According to the compared result, when the time diversity gain t is greater than the maximum time diversity gain K, the TDM 240 may output a failure message with respect to the diversity gain request, and the transmission antenna 260 may transmit the outputted failure message to the receiving apparatus 120. As a result, the transmission apparatus 110 may terminate a response procedure with respect to the diversity request of the receiving apparatus 120.
  • the TDM 240 may output a failure message for the diversity gain request, and the transmission antenna 260 may transmit the outputted failure message to the receiving apparatus 120.
  • the transmission apparatus 110 may terminate a response procedure with respect to the diversity request of the receiving apparatus 120.
  • the TDM 240 may determine K number of sub-streams (parallel signals), and perform time division multiplexing of the determined K number of sub- streams to thereby output the second serial signals. Also, when assignment of a transmission rate (or bandwidth) is requested from the receiving apparatus 120, the TDM 240 may compare, with a maximum transmission ratio, a transmission ratio of the requested transmission rate to a transmission rate for each of the parallel signals. Also, the TDM 240 may determine the number of parallel signals to correspond to the transmission ratio based on the compared result, and perform time division multiplexing of the determined number of parallel signals. Specifically, in a case where the transmission rate (or bandwidth) for each of the sub-streams (parallel signals) is W ⁇ B , the TDM 240 may compare a transmission rate (or bandwidth) for each of the sub-streams (parallel signals) is W ⁇ B , the TDM 240 may compare a transmission rate (or bandwidth) for each of the sub-streams (parallel signals) is W ⁇ B , the
  • the TDM 240 may output a failure message for the diversity gain request, and the transmission antenna 260 may transmit the outputted failure message to the receiving apparatus 120.
  • the transmitting apparatus 110 may terminate a response procedure for the diversity request of the receiving apparatus 120.
  • the TDM 240 may determine
  • the TDM 240 may compare, with a maximum time diversity gain, the sum of a transmission ratio of the requested transmission rate to another transmission rate for each of the parallel signals and the requested time diversity. Also, the TDM 240 may determine a number of the parallel signals to correspond to the maximum time diversity gain based on the compared result, and perform time division multiplexing of the determined number of parallel signals.
  • the TDM 240 may compare, with the maximum time diversity gain K, the
  • the TDM 240 may output a failure message for the diversity gain request, and the transmission antenna 260 may transmit the outputted failure message to the receiving apparatus 120.
  • the transmission apparatus 110 may terminate a response procedure for the diversity request and the transmission rate (bandwidth) request of the receiving apparatus 120.
  • the TDM 240 determine the number of sub-streams
  • the TDM 240 may determine the number of sub-streams (parallel signals) to be K, and perform time division multiplexing of the determined K number of sub-streams to thereby output the multiplexed sub-streams (parallel signals) as the second serial signals.
  • the upconverter 250 may receive an input of the outputted second serial signals, and convert the received signals into signals having a high frequency to thereby output.
  • the transmission antenna 260 may transmit the outputted second serial signals having the high frequency to the receiving apparatus 120.
  • FIG. 3 is a block diagram illustrating a receiving apparatus of a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention.
  • the receiving apparatus 120 may include a receiving antenna 310, a downconverter 320, a time division demultiplexer 330, a plurality of buffers 340, a plurality of demodulators 350, a plurality of channel decoder 360, and a Time Division Multiplexer (TDM) 370.
  • the receiving antenna 310 may receive second serial signals from the transmission apparatus 110. In this time, the second serial signals are converted into signals having a high frequency.
  • the downconverter 320 may receive an input of the second serial signals having a high frequency, and convert the received signals into signals having a low frequency to thereby output.
  • the time division demultiplexer 330 may receive an input of the second serial signals, which are converted into original signals having low frequency, and perform time division demultiplexing of the received second serial signals to thereby output the demultiplexed serial signals to a plurality of parallel signals.
  • the time division demutliplexer 330 may time division demultiplexing of the second serial signals in a demultiplexing ratio corresponding to the multiplexing ratio of the transmission apparatus 110.
  • the plurality of buffers 340 may temporarily store each of the outputted parallel signals.
  • the plurality of demodulators 350 may demodulate each of the stored parallel signals.
  • the plurality of channel decoders 360 may decode each of the demodulated parallel signals.
  • the time division multiplexer 370 may perform time division multiplexing of each of the decoded parallel signals to thereby restore the multiplexed parallel signals to as first serial signals, that is, original signals.
  • the receiving apparatus 120 may further include a low-pass filter
  • a down sampler 380 for lowering the speed of a receiving locked loop
  • a carrier sensor 385 for sensing whether signals can be received
  • a carrier frequency offset detector 390 for sensing whether signals can be received
  • a symbol synchronization detector 395 for removing high frequency noise from the second serial signals received from the transmission apparatus 110.
  • FIG. 4 is a block diagram illustrating a structure of a transmission packet used in a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention.
  • the transmission packet according to the present exemplary embodiment of the invention may be comprised of a preamble 410 and data 420, however, may be comprised of the preamble, a midamble, a pilot, data, and the like.
  • 420 may be changed to a single greater packet through the time division multiplexing.
  • the TDM 240 of FIG. 2 may perform time division multiplexing of the K transmission packets of the lower unit to thereby output the multiplexed K transmission packets as a single greater packet.
  • a k-th transmission signal of a lower unit from a time t may be represented
  • an output sampling period T s of the TDM (see reference numeral 240 of FIG. 2) may
  • a length of an integrated transmission packet obtained by performing time division multiplexing of the K transmission packets of the lower unit is represented by
  • transmission packet may be represented by [Equation 3]
  • L-X gains is denoted as h, , and 2 ⁇ ⁇ ⁇ ' I J i s satisfied with respect to each of the
  • FIG. 5 is a flowchart illustrating a transmission method of a Time Division
  • TDM Multiplexing
  • the transmission apparatus may receive an input of first serial signals from an external device or an internal memory means, and perform time division demultiplexing of the inputted first serial signals to thereby output the demultiplexed serial signals as a plurality of parallel signals. Specifically, the transmission apparatus may change the first serial signals received in serial into signals in parallel, and divide a space to thereby output as the plurality of parallel signals.
  • the transmission apparatus may encode each of the outputted parallel signals. Specifically, the transmission apparatus may convert each of the outputted parallel signals into digital signals to thereby output.
  • the transmission apparatus may modulate each of the encoded parallel signals. In this instance, the transmission apparatus may modulate each of the encoded parallel signals in a predetermined modulation scheme.
  • the modulation scheme may include a Frequency Shift Keying (FSK), Amplitude Shift Keying (ASK), Phase Shift Keying (PSK), Quadrature Amplitude Modulation (QAM), and the like.
  • the transmission apparatus may adjust a multiplexing ratio according to channel related-information of the transmission apparatus or the receiving apparatus, for example, transmitting/receiving channel states, frequency bandwidths, a user request-transmission rate, a Single-to-Noise Ratio (SNR), and the like. Specifically, the transmission apparatus may adjust a number of parallel flows according to the channel related-information.
  • SNR Single-to-Noise Ratio
  • the transmission apparatus may perform time division multiplexing of each of the modulated parallel signals in the adjusted multiplexing ratio to thereby output the modulated parallel signals. Specifically, the transmission apparatus performs time division multiplexing of the adjusted number of parallel flows (parallel signals) in the multiplexing ratio adjusted according to the channel related- information to thereby output the multiplexed parallel signals as the second serial signals.
  • the transmission apparatus may adjust a time diversity gain according to the channel related-information, and adjust the multiplexing ratio based on the adjusted time diversity gain. Also, the transmission apparatus may perform time division multiplexing of each of the parallel signals in the adjusted multiplexing ratio to thereby output the multiplexed parallel signals as the second serial signals.
  • the transmission apparatus may increase an amount of data that can be processed simultaneously by increasing the multiplexing ratio when the receiving apparatus requests a high transmission rate, and reduce the amount of the data by reducing the multiplexing ratio when the receiving apparatus requests a low transmission rate.
  • the transmission apparatus may perform time division multiplexing of each of the modulated parallel signals in the multiplexing ratio depending on the channel related-information, thereby variably adjusting the transmission rate.
  • the transmission apparatus may adjust the data transmission amount according to the request transmission rate from the receiving apparatus, thereby adjusting power consumption.
  • the transmission apparatus may be embodied in a parallel structure, thereby increasing an operation speed of all hardware in the high-speed system.
  • the process for adjusting the time diversity gain may be mainly classified into a case where the time diversity gain is requested from the receiving apparatus, and a case where assignment of a transmission rate or bandwidth is requested.
  • FIGS. 7 and 8 relate to the case where the time diversity gain is requested
  • FIG. 9 relates to the case where the assignment of the transmission rate or bandwidth is requested
  • FIG. 10 relates to a case where the time diversity gain and the assignment thereof are simultaneously requested.
  • the transmission apparatus may compare the requested time diversity gain with a maximum time diversity gain. Also, the TDM 240 may determine a number of the parallel signals to correspond to the maximum time diversity gain, and perform time division multiplexing of the determined number of parallel signals. Specifically, as shown in FIG. 7, in operation S710, the transmission apparatus
  • the transmission apparatus may compare the time diversity
  • the transmission apparatus may output a failure message for the diversity gain request, and transmit the outputted failure message to the receiving apparatus in operation S730. AS a result, the transmission apparatus may terminate a response procedure for the diversity request of the receiving apparatus. Conversely, when the time diversity gain t is smaller than or equal to the maximum time diversity gain K (in a direction of 'YES' of operation S720) based on the compared result, the transmission apparatus may determine MG t ( ⁇ K) number of sub-streams so that the number of sub-streams (parallel signals) satisfying the time
  • the transmission apparatus may determine K - MG 1 number of the remaining sub-streams.
  • the transmission apparatus may transmit K number of sub-streams to the receiving apparatus.
  • the transmission apparatus may determine the number of sub- streams to be K, and perform time division multiplexing of the determined K number of sub-streams to thereby output the multiplexed sub-streams as the second serial signals.
  • the transmission apparatus may receive a request for time diversity gains ⁇ G t , G t , ... , G t ⁇ with respect to M number of sub-streams (parallel signals) from the receiving apparatus. In this case, in operation
  • the transmission apparatus may compare a sum G of the requested time diversity gain with the maximum time diversity gain K.
  • the transmission apparatus may output a failure message for the diversity gain request, and transmit the outputted failure message to the receiving apparatus. As a result, the transmission apparatus may terminate a response procedure for the diversity request of the receiving apparatus
  • the transmission apparatus may determine
  • the transmission apparatus may determine the number of sub-streams to be K, and perform time division multiplexing of the determined K number of sub-streams to thereby output the multiplexed signals as the second serial signals.
  • the transmission apparatus may compare a transmission ratio of the requested transmission to a transmission rate for each of the parallel signals with a maximum transmission ratio. Also, the transmission apparatus may determine the number of the parallel signals to correspond to the transmission ratio, and perform time division multiplexing of the determined number of the parallel signals.
  • the transmission apparatus may receive a request for assignment of a transmission rate W B (or bandwidth) from the receiving apparatus.
  • the transmission rate (or bandwidth) for each of the sub-streams (parallel signals) may be W XB .
  • the transmission apparatus may compare a transmission ratio W B IW XB and the maximum transmission ratio K. When the transmission ratio W B IW XB is greater than the maximum transmission ratio K (in a direction of 'NO' in operation S920) according to the compared result, the transmission apparatus may output a failure message for the diversity gain request, and transmit the outputted failure message to the receiving apparatus in operation S930. As a result, the transmission apparatus may terminate a response procedure for the diversity request of the receiving apparatus.
  • the transmission apparatus may determine a number of sub- streams W B IW W satisfying W B /W lB ⁇ K in operation S940. Also, in operation S950, the transmission apparatus may transmit the determined number W B /W ]B of sub-streams to the receiving apparatus. As a result, the transmission apparatus may perform time division multiplexing of the determined number W B /W lB of sub-streams to thereby output the multiplexed sub-streams as the second serial signals.
  • the transmission apparatus may compare, with a maximum time diversity gain, the sum of a transmission ratio of the requested transmission rate to another transmission rate for each of the parallel signals and the requested time diversity. Also, the transmission apparatus may determine a number of parallel signals to correspond to the maximum time diversity gain based on the compared result, and perform time division multiplexing of the determined number of parallel signals. Specifically, as shown in FIG. 10, in operation SlOlO, the transmission apparatus may receive requests for a bandwidth W g with respect to a sub-stream
  • the transmission apparatus may compare, with a
  • the transmission apparatus may output a failure message for the diversity gain request, and transmit the outputted failure message to the receiving apparatus.
  • the transmission apparatus may terminate a response procedure for the diversity and transmission (bandwidth) request of the receiving apparatus.
  • the transmission apparatus may receive the outputted second serial signals to the receiving apparatus.
  • the transmission apparatus may convert the outputted second serial signals into signals having a high frequency, and transmit the high frequency- second serial signals to the receiving apparatus.
  • FIG. 6 is a flowchart illustrating a receiving method of a Time Division
  • TDM Multiplexing
  • the receiving apparatus may receive second serial signals from the transmission apparatus. Specifically, the receiving apparatus may receive the second serial signals which are converted into signals having a high frequency. Next, the receiving apparatus may receive an input of the low frequency-second serial signals, and convert the inputted serial signals into low frequency-serial signals to thereby output.
  • the receiving apparatus may receive the low frequency- second serial signals, and perform time division demultiplexing of the inputted second serial signals to thereby output the demultiplexed serial signals as a plurality of parallel signals.
  • the receiving apparatus may perform time division demultiplexing of the second serial signals in a demultiplexing ratio corresponding to the multiplexing ratio of the transmission apparatus to thereby output the demultiplexed serial signals as the plurality of parallel signals.
  • the receiving apparatus may temporarily store each of the outputted parallel signals in the plurality of buffers.
  • the receiving apparatus may demodulate each of the outputted parallel signals.
  • the receiving apparatus may decode each of the demodulated parallel signals.
  • the receiving apparatus may perform time division multiplexing of each of the decoded parallel signals to thereby restore the multiplexed parallel signals as the first serial signals, that is, original signals.
  • FIG. 11 illustrates an example of a transmission apparatus of an Orthogonal
  • Frequency Division Multiplexing (OFDM) system adopting a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention.
  • the transmission apparatus of the OFDM system may include a time division demultiplexer 1110, a plurality of channel encoders 1120, a plurality of inverse Fourier transformers 1130, a plurality of cyclic prefix inserting units
  • the time division demultiplexer 1110 may receive an input of first serial signals from an external device or internal memory means, and perform time division demultiplexing of the inputted first serial signals to thereby output the demultiplexed serial signals as a plurality of parallel signals. Specifically, the time division demultiplexer 1110 may change the first serial signals received in serial to signals in parallel, and divide a space to thereby output as the plurality of parallel signals.
  • the plurality of encoders 1120 may encode each of the outputted parallel signals.
  • the plurality of inverse Fourier transformers 1130 may perform inverse Fourier transforming of each of the encoded parallel signals.
  • the plurality of cyclic prefix inserting units 1140 may insert cyclic prefix to each of the inverse Fourier transformed parallel signals.
  • the plurality of buffers 1150 may temporarily store each of the parallel signals where the cyclic prefix is inserted.
  • the time division multiplexer 1150 may adjust a multiplexing ratio according to channel related-information such as channel states (transmitting/receiving), frequency bands, transmission rates, Signal-to-Noise Ratio (SNR), and the like. Specifically, the time division multiplexer 1150 may adjust a number of parallel flows according to the channel related-information.
  • the time division multiplexer 1150 may perform time division multiplexing of each of the parallel signals in the adjusted multiplexing ratio to thereby output the multiplexed parallel signals as second serial signals. Specifically, the time division multiplexer 1150 may perform time division multiplexing of the adjusted number of parallel flows (parallel signals) in the adjusted multiplexing ratio depending on the channel related-information to thereby output the multiplexed parallel signals as the second serial signals.
  • the digital-analog converter 1170 may convert the outputted second serial signals into analog signals to thereby output.
  • the transmission antenna 1180 may transmit the second serial signals outputted into the analog signals.
  • FIG. 12 illustrates an example of a receiving apparatus of an OFDM system adopting a time division multiplexing communication system with a parallel structure according to an exemplary embodiment of the present invention.
  • the receiving apparatus of the OFDM system may include a receiving antenna 1210, an analog-digital converter 1220, a time division demultiplexer 1230, a plurality of buffers 1240, a plurality of cyclic prefix removers 1250, a plurality of Fourier transformers 1260, a plurality of channel decoders 1270, and a time division multiplexer 1280.
  • the receiving antenna 1210 may receive second serial signals from a transmission apparatus.
  • the analog-digital converter 1220 may convert the received second serial signals into digital signals.
  • the time division demultiplexer 1230 may perform time division demultiplexing of the second serial signals converted into the digital signals to thereby output the demultiplexed serial signals as a plurality of parallel signals. In this instance, the time division demultiplexer 1230 may perform time division demultiplexing of the second serial signals in a demultiplexing ratio corresponding to the multiplexing ratio of the transmission apparatus to thereby output the demultiplexed serial signals as the plurality of parallel signals.
  • the plurality of buffers 1240 may temporarily store each of the outputted parallels signals.
  • the plurality of cyclic prefix removers 1250 may receive an input of each of the parallel signals from the plurality of buffers 1240, and remove the cyclic prefix inserted in the inputted parallel signals.
  • the plurality of Fourier transformers 1260 may perform Fourier transforming of each of the parallel signals where the cyclic prefix is removed to thereby output.
  • the plurality of channel decoders 1270 may decode each of the outputted parallel signals.
  • the time division multiplexer 1280 may perform time division multiplexing of each of the decoded parallel signals to thereby restore the multiplexed parallel signals to first serial signals, that is, original signals.
  • the transmitting/receiving method of the time division multiplexing communication system may be recorded in computer-readable media including program instructions to implement various operations embodied by a computer.
  • the media may also include, alone or in combination with the program instructions, data files, data structures, and the like.
  • the media and program instructions may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts.
  • Examples of computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD ROM disks and DVD; magneto-optical media such as optical disks; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, and the like.
  • Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter.
  • the described hardware devices may be configured to act as one or more software modules in order to perform the operations of the above-described exemplary embodiments of the present invention.
  • a Time Division (TD)-OFDM adopting the time division multiplexing communication system with the parallel structure according to the exemplary embodiments of the invention may perform communication using a frame structure below.
  • the frame structure may be devised as shown in FIG. 13.
  • the frame structure may transmit a short symbol (short preamble) line where an OFDM symbol of a length of 128 samples is repeated twelve times to thereby start the frame.
  • the last twelfth symbol is obtained by rotating a phase of the previous eleventh symbol by 180 degrees.
  • a long symbol (long preamble) composed of 576 samples subsequent to the short symbol line may be used for inferring channels.
  • signal symbol (signal field) succeeding after the long symbol may be devised for transmitting information needed for demodulating receiving packets such a modulation schemes, channel code rate, a number of bytes included in the frame (data length), a scrambler seed, and Cyclic Redundancy Check (CRC) parity.
  • Each data symbol is composed of 576 samples, and a number of data symbols may vary according to the number of bytes desired to be transmitted.
  • IFFT Inverse Fast Fourier Transform
  • the subcarrier values may be obtained from a permutation of a maximum 31 length.
  • the subcarrier used for the short symbol may be selected by four times (factor) down-sampling without using a low-pass filter to thereby obtain a power such as input signals.
  • the present invention may be accomplished by only using the subcarrier maintained to prevent spectrums from being superposed one on another after down- sampling.
  • the down-sampling may be devised not to destroy repetition characteristics of a time domain permutation. Since a single subcarrier occupies in an identical position from each four subcarriers, the repetition characteristics may be maintained despite the superposed spectrum due to the dawn-sampling.
  • Two characteristics such as repeating and maintaining the identical power even after the down-sampling may enable a receiver to use the short symbol received without the low- pass filter.
  • the two characteristics may be applicable in each of four frequency domains before operating a preamble.
  • S k denotes a frequency domain value illustrated in Table 1
  • ⁇ f denotes an interval between a subcarrier and a carrier corresponding to 3.9 MHz as illustrated in Table 3. Twelve times repetition of the short symbol may be acquired by repeating the result of Equation 1 three times. A negative number of the last symbol may denote polarity reversion.
  • Equation 7 The long symbol may be devised to be created by IFFT operation with respect to a frequency domain permutation of Equation 7, which is represented by [Equation 7]
  • This permutation may be acquired from a maximum length permutation having 511 length.
  • the IFFT operation may perform Equation 8, which is represented by [Equation 8]
  • L k denotes a frequency domain value illustrated in Equation 2
  • ⁇ f denotes an interval between the subcarrier and the carrier corresponding to 3.9 MHz illustrated in Table 3
  • Tcp denotes a cyclic prefix (CP) corresponding to 32 nsec illustrated in Table 3.
  • the signal symbol structure may be devised for transmitting information needed for modulating receiving packets such as Modulation and Code rate Symbol (MCS, 3 bits), a number of bytes included in the frame (length: 16 bits), scrambler seed (7 bits), CRC parity (12 bits), tail for initialization of a convolutional decoder (6 bits), and the like.
  • MCS Modulation and Code rate Symbol
  • a number of bytes included in the frame length: 16 bits
  • scrambler seed 7 bits
  • CRC parity (12 bits
  • tail for initialization of a convolutional decoder (6 bits), and the like.
  • a length field is a length of data being transmitted in a byte unit in a data symbol domain of the frame.
  • CRC signals may be used for detecting reception errors in the signal symbol.
  • a CRC creation polynomial is X n + X u + X 3 + X 2 + X + 1 . '0' of six-tail bits is received in a CRC error detector from the end of CRC decoding of the signal symbol, thereby terminating the decoding operation.
  • Data in the signal field may be converted into a scrambler determined as the initial value of a first hexadecimal 3 F, and encoded using an error correction encoder of 1/2. 192-bits of data encoded using the error correction encoder is repeated for four times before interleaving. 386 subcarriers are modulated in a Quadrature Phase Shift Keying (QPSK) scheme using 768-bits of data obtaining by repeating the four times repetition.
  • QPSK Quadrature Phase Shift Keying
  • the IFFT operation may be used for modulation of the subcarrier as shown in Equation 2.
  • the OFDM modulation technology may be used for transmitting data through radio signals of 60 GHz frequency bandwidth.
  • Parameter of the modulation technology is summarized in Table 3. [Table 3] OFDM parameter

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Abstract

La présente invention concerne un système de communication à multiplexage temporel ou 'TDM' (Time Division Multiplexing) à structure parallèle et un procédé correspondant. Un appareil de transmission du système de communication à multiplexage temporel à structure parallèle comprend un démultiplexeur temporel ou 'TDDM' (Time Division DeMultiplexer) servant à effectuer le démultiplexage temporel de premiers signaux série entrée de façon à produire en sortie les signaux série démultiplexés sous forme d'une pluralité de signaux parallèles, une pluralité de modulateurs servant à moduler les signaux parallèles respectifs produits en sortie, un multiplexeur temporel ou 'TDM' (Time Division Multiplexer) servant à ajuster le rapport de multiplexage en fonction d'une information se rapportant au canal, et d'exécuter le multiplexage temporel de chacun des signaux parallèles modulés dans le rapport de multiplexage ajusté de façon à produire ainsi les signaux parallèles multiplexés sous forme de deuxièmes signaux série, et une antenne de transmission pour transmettre les deuxième signaux série produits en sortie.
PCT/KR2008/004615 2007-08-10 2008-08-08 Système de communication à multiplexage temporel à structure parallèle, et procédé correspondant WO2009022817A1 (fr)

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CN103814531A (zh) * 2011-09-19 2014-05-21 阿尔卡特朗讯 改进具有多个天线的网络元件处的发射增益的方法
JP2014225889A (ja) * 2009-03-27 2014-12-04 クゥアルコム・インコーポレイテッドQualcomm Incorporated データフレームを送信及び受信するシステム及び方法
CN117632836A (zh) * 2022-08-17 2024-03-01 上海合见工业软件集团有限公司 一种基于多fpga芯片的数据传输系统

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KR20050019265A (ko) * 2003-08-18 2005-03-03 삼성전자주식회사 시분할다중접속/직교주파수분할다중화 시스템의 송신방법및 그 장치와, 수신방법 및 그 장치

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JP2014225889A (ja) * 2009-03-27 2014-12-04 クゥアルコム・インコーポレイテッドQualcomm Incorporated データフレームを送信及び受信するシステム及び方法
CN103814531A (zh) * 2011-09-19 2014-05-21 阿尔卡特朗讯 改进具有多个天线的网络元件处的发射增益的方法
CN117632836A (zh) * 2022-08-17 2024-03-01 上海合见工业软件集团有限公司 一种基于多fpga芯片的数据传输系统

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