OFDM receiving and dispatching system for high speed mobile environment

OFDM receiving and dispatching system for high speed mobile environment

  • CN 101,115,047 A
  • Filed: 08/03/2007
  • Published: 01/30/2008
  • Est. Priority Date: 08/03/2007
  • Status: Active Application
First Claim
Patent Images

1. an OFDM receive-transmit system that is applicable to high-speed mobile environment is characterized in that containing transmitter and receiver, wherein:

  • Transmitter contains;

    first deserializer (102), and two pretreatment units (1031) and (1032), N/2 point IFFT unit (1011) and (1012), first parallel-to-serial converter (104), wherein,First deserializer (102), be used for N-L data parallelization with the serial input, N is the ofdm system number of sub carrier wave, L is more than or equal to zero integer less than N, be the sub-carrier signal number that increases altogether in the above-mentioned two pretreatment units processing, the output of deserializer links to each other with above-mentioned two pretreatment unit inputs;

    Two pretreatment units (1031) and (1032), the parallel data stream that is used for being mapped to above-mentioned two IFFT unit inputs carries out preliminary treatment, and input links to each other with the first deserializer output, exports two frequency-domain sub-symbols X respectively 1And X 2To above-mentioned two IFFT unit inputs;

    Described pretreatment unit is for pressing following three step process from the N-L data of first deserializer input;

    Pretreatment unit (1031) produces L earlier 1The given data symbol of individual any appointment, comprising the remainder according to symbol, L 1For more than or equal to zero smaller or equal to the L integer, and be placed into frequency-domain sub-symbols X at random 1Subcarrier on, as X to be exported 1A part, its corresponding L 1Individual sub-carrier indices set is labeled as K 1, K 1The element span be more than or equal to 1 integer smaller or equal to N/2;

    Then, pretreatment unit (1032) produces nonnegative integer L 2The individual known or remainder is according to symbol, L 2=L-L 1, and be placed into frequency-domain sub-symbols X at random 2Subcarrier on, as X to be exported 2A part, its corresponding L 2Individual sub-carrier indices set is labeled as K 2, K 2The element span be more than or equal to 1 integer smaller or equal to N/2, and K 1

    K 2

    , i.e. K 1And K 2Not overlapping;

    If K 1

    K 2

    Ω

    then repeats to be mapped at random X 2Process, until K 1

    K 2

    , and by K 1And K 2Union K 1

    K 2Produce sub-carrier indices vector m;

    A N-L data to two pretreatment unit of first deserializer output, pretreatment unit is placed into X respectively arbitrarily with it 1And X 2In on the subcarrier of the value of not putting, X wherein 1The middle positive integer N/2-L that places 1Individual data, X 2The middle positive integer N/2-L that places 2Individual data satisfy the data subcarrier index and index vector m is not overlapping;

    Two pretreatment units are exported the X after the processing respectively 1And X 2Two N/2 point IFFT unit (1011) and (1012) are used to produce two OFDM subsymbols, and input links to each other with two pretreatment unit outputs respectively, and output links to each other with the first parallel-to-serial converter input;

    First parallel-to-serial converter (104) is used for serially concatenated is carried out in the output of above-mentioned two IFFT unit, forms new OFDM symbol and adds zero suffix, and input links to each other with above-mentioned two IFFT unit outputs, and output sends signal;

    Receiver contains;

    second deserializer (204), and N point FFT unit (202), interference eliminated receiving system (201), two channel estimation and equalization unit (2031) and (2032), second parallel-to-serial converter (205), wherein,Second deserializer (204) is used for the input traffic parallelization with serial, and input is that the transmitter that receives sends signal, and output links to each other with above-mentioned N point FFT unit input;

    N point FFT unit (202) is used for input time-domain signal biography is changed to frequency-region signal, and input links to each other with the second deserializer output, and output links to each other with above-mentioned interference eliminated receiving system input;

    Interference eliminated receiving system (201), be used to eliminate between subsymbol disturb and subcarrier between disturb, input links to each other with N point FFT unit (202) output, output links to each other with above-mentioned two channel estimation and equalization unit inputs;

    Described interference eliminated receiving system contains;

    even withdrawal device, and strange withdrawal device, fixed coefficient linear filter, the subcarrier withdrawal device is mended basic subcarrier maker, adder, subtracter, wherein;

    The idol withdrawal device is used for extracting the subcarrier in frequency domain signal of the even number index marker correspondence of exporting receiving terminal N point FFT unit Input links to each other with the parallel output terminal of above-mentioned N point FFT unit, and output links to each other with subcarrier withdrawal device input and adder input;

    Strange withdrawal device is used for extracting the subcarrier in frequency domain signal of the odd number index marker correspondence of exporting receiving terminal N point FFT unit Input links to each other with the parallel output terminal of above-mentioned N point FFT unit, and output links to each other with fixed coefficient linear filter input;

    The fixed coefficient linear filter is used for producing the difference signal of first subsymbol with respect to second subsymbol , the fixed coefficient linear filter has two inputs, and an input links to each other with the basic subcarrier maker output of benefit, and an input links to each other with strange withdrawal device output, and output is connected to adder and subtracter input simultaneously;

    Described fixed coefficient linear filter produces by following three steps Generate the coefficient matrix F of said fixing coefficient linear filter e[F o| S] -1, comprise, according to N rank normalization DFT matrix F (N)Submatrix F oAnd F e, its matrix element is respectively Fo(i,j)=F2i+1,j(N)With Fe(i,j)=F2i,j(N) Regeneration F eThe S of submatrix, its L is capable of F eCapable vector in choose the corresponding above-mentioned transmitting terminal preliminary treatment index marker vector m of corresponding line index marker, its element S (i, j)=F E (m (i), j)Matrix F oConstitute one with matrix S Combinatorial matrix [F o| S], calculate the inverse matrix [F of this combinatorial matrix o| S] -1, and and matrix F eMultiply each other in the right side, acquisition said fixing coefficient linear filter Coefficient matrix F e[F o| S] -1Obtain according to above-mentioned strange withdrawal device Vector With the vectorial R in L * 1 that mends basic subcarrier maker generation Known, constitute one The input combinatorial matrix With above-mentioned input combinatorial matrix With above-mentioned coefficient matrix F e[F o| S] -1Multiplying each other in the right side, produces the output vector of fixed coefficient linear filter , and output The subcarrier withdrawal device, the sub-carrier indices that is used for describing by pretreatment unit from the output signal of even withdrawal device is gathered mark K 1And K 2Extract an integer L known subcarrier, input links to each other with the output of above-mentioned even withdrawal device, and output links to each other with the basic subcarrier maker input of benefit;

    Mend basic subcarrier maker, be used for producing the basic subcarrier R of benefit integer L the known subcarrier from being no less than of above-mentioned subcarrier withdrawal device acquisition Known, to satisfy The benefit base requirement that can find the solution;

    Input links to each other with the output of above-mentioned subcarrier withdrawal device, and output links to each other with the input of fixed coefficient linear filter;

    The basic subcarrier maker of described benefit produces R by following two steps Known;

    To the index set mark K that describes in the pretreatment unit 1Corresponding sub-carrier signal get negative back as R to be exported KnownThe sub-carrier signal element of middle manipulative indexing mark is to the index set mark K that describes in the pretreatment unit 2Corresponding sub-carrier signal directly as R to be exported KnownThe sub-carrier signal element of middle manipulative indexing mark;

    Output R KnownAdder, be used for additional calculation is carried out in the output of said fixing coefficient linear filter and the output of even withdrawal device, adder has two inputs, an input links to each other with the output of above-mentioned even withdrawal device, an input links to each other with said fixing coefficient linear filter, is output as first subsymbol frequency-region signal after the recovery , be first output of interference eliminated receiving system (201);

    Subtracter, be used for subtraction is carried out in the output of said fixing coefficient linear filter and the output of even withdrawal device, subtracter has two inputs, an input links to each other with the output of above-mentioned even withdrawal device, an input links to each other with said fixing coefficient linear filter output, is output as second subsymbol frequency-region signal after the recovery , be second output of interference eliminated receiving system (201);

    Two channel estimation and equalization unit (2031) are to (2032), be used for estimating channel and balanced received signal by minimum side (LS) or Minimum Mean Square Error (MMSE) algorithm, input links to each other with interference eliminated receiving system output, and output links to each other with the second parallel-to-serial converter input;

    Second parallel-to-serial converter (205) is used for the also line output of above-mentioned two channel estimation and equalization unit is carried out serially concatenated, and input links to each other with two channel estimation and equalization unit outputs, is output as received signal.

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