Combination optimization self-adaptive frequency domain blind equalization method and system

1. A combined optimization of the adaptive the frequency range is blind equalization method, characterized in that comprises the following steps:

Step A, emission signal a (n) through channel h (n) receive channel output signal x (n): x (n) = h^T (n) a (n); wherein a (n) to transmit a signal, is independent of the distribution of the; h (n) is the finite-impulse-response channel; n for time sequence; said T transpose;

Step B, w by the channel noise signal (n) and step A x of the channel output signal (n) to obtain the frequency domain equalizer u time domain input signal (n): u (n) = x (n) + w (n); w (n) is the additive white Gaussian noise channel;

C steps, the step B u the time domain input signal (n) for L-point fast Fourier transform FFT U is the input signal of frequency domain equalizer (N), representing a N the number of data points L, L is a positive integer;

Step D, step C the U input signal of frequency domain equalizer (N) obtained by the frequency domain equalizer adjust its output frequency domain signal Y₁ (N): Y₁ (N) = F₁ (N) U (N), wherein F₁ (N) adjust the frequency domain of the equalizer vector frequency range power ; U (N) the frequency domain adaptive equalizer obtain the output of the frequency domain signal Y₂ (N): Y₂ (N) = F₂ (N) U (N), wherein F₂ (N) into the frequency domain adaptive equalizer frequency range power vector;

Step E, the frequency domain in step D output signal of frequency domain equalizer adjust Y₁ (N) as a L point IFFT is reverse fast Fourier transform of the frequency domain equalizer adjust the output time domain signal y₁ (n): y₁ (n) = IFFT[Y₁ (N)], to the frequency domain adaptive equalizer output frequency domain signal Y₂ (N) as L-point inverse fast Fourier transform to IFFT of the adaptive equalizer in the frequency domain of the output time domain signal y₂ (n): y₂ (n) = IFFT[Y₂ (N)];

Step F, step E the frequency domain equalizer adjust the output time domain signal y₁ (n) and frequency domain adaptive equalizer output the signal of time domain y₂ (n), λ through the combined parameter (n) combined output time-domain signal are combined y (n): y (n) = λ (n) y₁ (n) + [1-    (n)] y₂ (n), wherein 0     λ (n) ≤ 1;

G steps, steps of the combined F y of the output time domain signal (n) of the decision device to obtain a decision output time-domain signal; The time delay sequence △ is ;

Wherein the frequency domain equalizer adjust frequency range power vector F₁ (N) to update by the formula:

F₁ (N+ 1) = F₁ (N) + μ₁ C₁ (N) U^* (N);

In the formula, μ₁ to step of iteration, is fixed constant; U^* (N) to U (N) conjugated; C1(N)=C1,Re(N)+jC1,Im(N)=[R2-Y1,Re2(N)]Y1,Re(N)+j[R2-Y1,Im2(N)]Y1,Im(N)Adjust the frequency domain to frequency domain error signal of the equalizer, Y_1,Re (N), Y_1,Im (N) the output of the frequency domain signal Y₁ (N) of the real part and the imaginary part; a transmitted signal (n) of frequency-domain modulus value R² for transmit signal a (n) of the time-domain modulus value r2=E[aRe4(n)]/E[aRe2(n)]=E[aIm4(n)]/E[aIm2(n)]The L-point fast Fourier transform FFT; mathematical expectations expressed E; a_Re (n) and a_Im (n) respectively representing a transmitted signal (n) of the real part and the imaginary part; As the imaginary number unit; C_1,Re (N) and C_1,Im (N) the output signal of frequency domain respectively C₁ (N) of the real part and the imaginary part;

Wherein the adaptive equalizer in the frequency domain vector frequency range power F₂ (N) to update by the formula:

F₂ (N+ 1) = F₂ (N) + μ₂ E₂ (N) U^* (N);

In the formula, μ₂ to step of iteration, is fixed constant; Adaptive equalizer the frequency domain to the frequency domain error signal, The decision output signal The L-point fast Fourier transform FFT;

Combination parameter λ (n) through the auxiliary parameter β (n) is defined as:

In the formula, Is in β (n) is a function of the self-variable, sgm[β (n)] = [1 + e^-β(n)]^-1, 0     λ (n) ≤ 1, when λ (n) = 1 when, β (n) = β⁺, when λ (n) = 0 when, β (n) =-β⁺, β⁺ is a normal number , β (n) ∈ [-β⁺, β⁺];

Β (n) update formula is:

Wherein c(n)=[r-yR2(n)]yR(n)+j[r-yIm2(n)]yI(n),As a function of Β (n-1) to the derivative, in other words Superscripts * said conjugated ; {x} expressed Re x that fetching the real part; Is step-size, ρ_β is a constant, p (n) =ηp (n-1) + [1-   ] | y₁ (n)-y₂ (n) |² in section n time signal y₁ (n)-y₂ (n) power estimation, 0 < η < 1 is a forgetting factor.

2. Combined optimization of the adaptive the frequency range is blind equalization method according to Claim 1, characterized in that said frequency domain adjust frequency range power of the equalizer vector F₁ (N) update formula obtained through the following steps: the frequency domain equalizer adjust the definition of the cost function in the frequency domain JFMMA(N)=E{[R2-Y1,Re2(N)]2}+E{[R2-Y1,Im2(N)]2},And by J_FMMA (N) the F₁ (N) gradient obtained for, wherein E expressed mathematical expectation, with.

3. Combined optimization of the adaptive the frequency range is blind equalization method according to Claim 1, characterized in that the frequency domain adaptive equalizer vector frequency range power F₂ (N) update formula obtained through the following steps: defining the frequency domain adaptive equalizer in the frequency domain of the cost function JFLMS(N)=E{|A^(N-Δ)-Y2(N)]|2},And by J_FLMS (N) the F₂ (N) gradient obtained for.

4. Combined optimization of the adaptive the frequency range is blind equalization method according to Claim 1, characterized in that the stated β (n) update formula obtained through the following steps: the whole combination optimization adaptive blind equalization of time domain of the system of the cost function is defined as JMMA(n)=E{[r2-yRe2(n)]2}+E{r2-yIm2(n)]2},And by J_MMA (n) of the auxiliary parameter β (n) to the gradient.

5. One kind is used for realizing claim 1-4 the arbitrary one of the combination of balanced the frequency range is blind method for optimization of the adaptive system, comprising:

1st FFT fast Fourier transform unit, a transmitting signal for the (n) through channel h (n) and adding w channel noise signal (n) to obtain the frequency domain equalizer u time domain input signal (n), for L-point fast Fourier transform FFT to obtain the frequency domain equalizer input frequency domain signal U (N);

The frequency domain equalizer adjust, is used for receiving the input signal of frequency domain equalizer U (N) and output frequency domain signal Y₁ (N), 1st its power vector according to the output value of the error difference to update a single $;

1st an inverse fast Fourier transform unit IFFT, adjust for the frequency domain output signal of frequency domain equalizer Y₁ (N) selects counter to L and a fast Fourier transform of the output time domain signal of the IFFT y₁ (n);

1st error difference generation unit, the frequency domain is used to adjust the output signal of frequency domain equalizer Y₁ (N) produce frequency domain adjust the error signal in the frequency domain of the equalizer C₁ (N) adjust output frequency domain and frequency domain error signal of the equalizer;

Adaptive equalizer in the frequency domain, is used for receiving the input signal of frequency domain equalizer U (N) and output frequency domain signal Y₂ (N), 2nd its power vector according to the output value of the error difference to update a single $;

2nd an inverse fast Fourier transform unit IFFT, is used for the frequency domain adaptive equalizer output frequency domain signal Y₂ (N) selects counter to L and a fast Fourier transform of the output time domain signal of the IFFT y₂ (n);

Parameter combination unit, used for receiving y₁ (n), y₂ (n), λ and the combined parameter (n) are combined y combined output time-domain signal (n), then output to the decision device;

Decision device, for receiving a combined y of the output time domain signal (n) and decision output time-domain signal;

2nd FFT fast Fourier transform unit, is used for receiving the decision output signal And L-point fast Fourier transform FFT;

2nd error difference generation unit, is used for receiving the 2nd fast Fourier transform unit output value and frequency domain adaptive equalizer output frequency domain signal Y₂ (N) and output of the frequency domain adaptive equalizer error signal in the frequency domain.