Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
  • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
  • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
  • H04L1/1812—Hybrid protocols; Hybrid automatic repeat request [HARQ]
  • H04L1/1819—Hybrid protocols; Hybrid automatic repeat request [HARQ] with retransmission of additional or different redundancy
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
  • H04L1/0009—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L27/00—Modulated-carrier systems
  • H04L27/26—Systems using multi-frequency codes
  • H04L27/2601—Multicarrier modulation systems
  • H04L27/2602—Signal structure
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L1/00—Arrangements for detecting or preventing errors in the information received
  • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
  • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
  • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
  • H04L1/1829—Arrangements specially adapted for the receiver end
  • H04L1/1835—Buffer management
  • H04L1/1845—Combining techniques, e.g. code combining

Definitions

• the invention relates to a method for coding data blocks for transmission in a radio communication system.
• a typical multicarrier transmission method is the so-called “Orthogonal Frequency Division Multiplexing (OFDM)" radio transmission method in which carriers called “subcarriers” are used to transmit symbols.
• OFDM Orthogonal Frequency Division Multiplexing
• a multi-carrier transmission method offers the advantage of a high data rate transmission with a low receiver overhead. In addition, it is very robust against temporal fluctuations of properties of the radio transmission channel.
• a “chunk” is dimensioned by a number
• Multicarriers or Subcarrier on the one hand and by a defined, the Mutliuzan or Subcarrier assignable period of time on the other. For example, several adjacent subcarriers are used to dimension a "chunk".
• the dimensions of a "chunk” are determined depending on radio transmission channel properties.
• the radio transmission channel properties are determined, for example, by channel estimation methods.
• a transmitter-side adaptation of a transmission power and / or a selected modulation of the transmission signal takes place, as well as the selection of suitable subcarriers or multicarriers.
• a considered “chunk” in terms of a so-called “flat fading” in the frequency domain and a constant temporal behavior in the time domain dimensioned makes it possible to adapt the radio transmission to be carried out adaptively to the properties of the radio transmission channel.
• QoS Quality of Service
• coding methods or error correction codes are used.
• an achievable useful data throughput depends on the coding method used, since, for example, in the case of very secure data transmission with a complex error correction code, a high number of redundancy bits has to be transmitted.
• data blocks are added as a function of predetermined quality-of-service requirements a so-called "outer” coding with a first, "outer” code encoded or encoded.
• the data blocks encrypted with the outer code are re-encrypted or coded with a so-called “inner” coding with a second, “inner” code.
• This second coding takes place in dependence on properties or radio channel properties of those "chunks" which are to be used for transmission.
• the outer coding is preferably carried out in a layer 2 referred to as "link layer” and the inner coding is preferably carried out in a layer 1 designated as "physical layer".
• the outer coding is preferably carried out with an error correction code whose code length or code rate is flexibly adjustable.
• the adjustment is adapted to the respective length and adapted to error correction requirements of a layer 2 data block or data packet.
• the inner coding is preferably carried out as a function of a selected modulation which is used for radio transmission.
• a so-called “coset code” or a “trellis code” modulation could be used.
• the inventive method realizes an adaptive and optimal approximation of a code rate per "chunk" to the properties of radio transmission channels or "chunks".
• FIG. 1 shows the inventive method based on three data packets or data blocks DPI, DP2 and DP3 of an OFDM radio communication system.
• Two data blocks DP2 and DP3 of a layer 3 are combined in the layer 2 to form a data block DP23 as a link-layer data block, while the data block DPI of the layer 3 arrives as a data block DPI to the layer 2.
• the data block DPII has a header RBLI and the data block DP23 has a header RB23, wherein each header RBLI, RB23 includes a respective CRC code and control information.
• the data block DPlI is supplied to an outer coding together with the header RBlI, while the data block DP23 is supplied together with the header RB23 to an outer coding.
• the outer coding is selected taking into account a Quality of Service requirement and a selected traffic class.
• a trivial error correction code could also be used for the outer coding if the code length assigned to a "chunk" is suitable for fulfilling the error correction requirements of a considered data packet.
• a new data block DPII1 is formed from the data block DPII and the header RBII, which has redundancy bits within a region RBLI1.
• a new data block DP123 is formed from the data block DP23 and the header RB23 and has redundancy bits within a range RB123.
• the data block DPII1 and its redundancy area RBlIl is supplied to a partitioning and an internal coding, this taking place depending on the characteristics of the radio transmission resources "chunk” ckl and ck2 to be used. This results in further redundancy bits in areas RB51 and RB52.
• the data block DP123 and its redundancy area RB123 are supplied to partitioning and internal coding, depending on the characteristics of the radio transmission resources "chunks" ck3 to ck7 to be used. This results in additional redundancy bits in areas RB61 to RB65.
• modulation and the mapping take place on the respective carrier frequencies or subcarriers as a function of radio transmission channel properties.
• a soft -UT decoding of the "inner” code is carried out on the receiver side.
• the softoutput information is dispensed with.
• the soft output information is collected and used to decode the outer code. After successful decoding of the outer code, the Layer 2 header is verified. Then the payload data is transferred to the network layer.
• this is the codeword associated with chunk's ckl and ck2, or the codeword associated with chunk's ck3 through ck7.
• Short data packets that require low transmission times are coded and transmitted only with the inner code, the outer coding can then be dispensed with.
• a radio transmission resource or "chunk" is used by at least two subscribers and is thus assigned to these subscribers.
• the participants are distinguishable, for example, by different CDMA codes or by different codes.
• the first and / or the second code can be set or selected by a subscriber within the framework of the quality of service requirements.
• the subscriber is offered suitable code combination of first and second code.

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Publications (1)

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• 2005
  • 2005-05-04 AT AT05009853T patent/ATE476026T1/de active
  • 2005-05-04 DE DE502005010006T patent/DE502005010006D1/de active Active
  • 2005-05-04 EP EP05009853A patent/EP1720273B1/fr not_active Not-in-force
• 2006
  • 2006-04-25 CN CN2006800150106A patent/CN101253721B/zh not_active Expired - Fee Related
  • 2006-04-25 US US11/919,872 patent/US8054740B2/en not_active Expired - Fee Related
  • 2006-04-25 EP EP06754840A patent/EP1880497A1/fr not_active Withdrawn
  • 2006-04-25 WO PCT/EP2006/061816 patent/WO2006117313A1/fr active Application Filing

Non-Patent Citations (1)

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