Claims
- 1. In a communication system where QPSK modulation is used to transmit data on a carrier frequency, the improvement wherein a carrier frequency phase reference is derived using a threshold extension block phase estimator (TEBPE) as described by the following equations: θ^=tan-1[∑k(ykD_k-xkE_k)∑k(xkD_k+ykE_k)]where{overscore (D)}k=tanh(Pkcos(φk−{overscore (θ)})) {overscore (E)}k=tanh(Pksin(φk−{overscore (θ)})) Pk=Arkσk2with and input signal given bysk=xk+jykexp(jφk) xk=A[Dkcos(θk)−Eksin(θk)]+nk yk=A[Dksin(θk)+Ekcos(θk)]+mk where A is the signal amplitude, and Dk and Ek are the in-phase and quadrature data streams with value ±1, θk is an input signal phase, φk is a phase of a signal plus noise, rk is an amplitude of a signal plus noise, nk is an input noise, mk is a quadrature noise, and the noise variance isvar(nk)=var(mk)=σn2.
- 2. In a spread spectrum communication system where QPSK modulation is used to transmit data on a carrier frequency, the improvement wherein a carrier frequency phase reference is derived using a threshold extension block phase estimator (TEBPE) as characterized by the following equations: θ^=tan-1[∑k(ykD_k-xkE_k)∑k(xkD_k+ykE_k)]where{overscore (D)}k=tanh(Pkcos(φk−{overscore (θ)})) {overscore (E)}k=tanh(Pksin(φk−{overscore (θ)})) Pk=Arkσk2with the input signal given bysk=xk+jyk=rkexp(jφk) xk=A[Dkcos(θk)−Eksin(θk)]+nk yk=A[Dksin(θk)+Ekcos(θk)]+mk where A is the signal amplitude, and Dk and Ek are the in-phase and quadrature data streams with value ±1, and the noise variance isvar(nk)=var(mk)=σn2.
- 3. In a communication system where QPSK modulation is used to transmit data on a carrier frequency, the improvement wherein a carrier frequency phase reference is derived using a threshold extension block phase estimator (TEBPE).
- 4. In a spread spectrum communication system where QPSK modulation is used to transmit data on a carrier frequency, the improvement wherein a carrier frequency phase reference is derived using a threshold extension block phase estimator (TEBPE).
Parent Case Info
This application is the subject of provisional application Serial No. 60/058,860 filed Sep. 12, 1997 entitled AN IMPROVED THRESHOLD EXTENSION BLOCK PHASE ESTIMATOR FOR QUASI-COHERENT COMMUNICATIONS SYSTEM.
US Referenced Citations (4)
Provisional Applications (1)
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Number |
Date |
Country |
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60/058860 |
Sep 1997 |
US |