Binary Phase Shift Keying Modulation Research Articles

Suppression of idler spectral broadening in highly efficient fiber four-wave mixing by binary-phase-shift-keying modulation of pump wave

Proposes and demonstrates a novel method of suppressing spectral broadening of the idler wave, which is generated in fiber four-wave mixing (FWM) pumped by a continuous wave. In this scheme, binary-phase-shift-keying (BPSK) modulation of the pump wave broadens the pump spectrum so that the Brillouin threshold for the pump power is increased, whereas it never affects the spectrum of the idler wave. By the 2-Gb/s BPSK modulation of the pump wave, we achieve a FWM efficiency as high as 10 dB, maintaining a side-band suppression ratio of the idler wave larger than 25 dB.

A direct Ku-band linear subharmonically pumped BPSK and I/Q vector modulator in multilayer thin-film MCM-D

A direct Ku-band linear subharmonically pumped binary phase-shift keying (BPSK) and in-phase/quadrature (I/Q) vector modulator have been developed using multilayer thin-film multichip module (MCM-D) technology. All passives are integrated in the low cost MCM-D substrate. To the authors knowledge, this is the first modulator based on thin-film integrated passive components. The subharmonic mixing is performed using a beam-lead antiparallel diode pair mounted onto the MCM using thermocompression. A custom diode model has been developed and verified using nonlinear network analyzer measurements: an excellent agreement between the measured and simulated powers and phases for more than nine harmonics is demonstrated. Additionally, it is shown that an optimal reactive termination for the third harmonic of the local oscillator (LO) exists such that a very flat BPSK mixer conversion is obtained. This is validated by measurements that indicate a /spl plusmn/0.25-dB variation on the conversion loss for an LO frequency varying from 6.8 to 7.6 GHz. The I/Q vector modulator consists of a Wilkinson power divider, a coplanar-waveguide Lange coupler, and two BPSK modulators. It has a measured image rejection better than -27 dB over the RF range of 13.4-15.2-GHz band (corresponding to a vector phase and amplitude error lower than 2/spl deg/ and 1%). The image rejection is even better than -32 dB over the very small aperture terminal band (RF: 14-14.5 GHz).

Phase shift keying using optical delay modulation for millimeter-wave fiber-optic radio links

We propose a novel phase shift keying technique that uses optical delay modulation for fiber optic radio links. Using only a 2/spl times/1 switch and a delay line, this technique enables modulation of a millimeter-wave carrier at bit rates of several gigabits per second or higher, where high-speed devices are not needed. Binary phase shift keying (BPSK) was experimentally demonstrated, 2-Gb/s data signal on a 40-GHz carrier was transmitted over a 5-km optical fiber without any error. The coherent crosstalk noise, due to insufficient extinction ratio of optical switches, was evaluated. The BPSK modulation technique can he extended to multiphase shift-keying modulation.

BPSK and QPSK modulations of an oscillating antenna for transponding applications

An oscillating antenna allowing binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK) is demonstrated. The modulating signals are applied to a PIN diode switch and an injection-locked oscillator. Experimental results are presented, including constellation diagrams of the radiated signal and typical waveforms of demodulated signals.

Probability of error for BPSK modulation from electrostatic interference [in orbital situation

In an orbital situation any spacecraft is bombarded by charged particles that span a broad range of energies. Some of the particles may be trapped within the materials of the spacecraft. Recent data indicates that an S-band phased-array antenna on a spacecraft may experience electrostatic discharges from such ion deposition at the elements of the array. These discharges may induce RF interference of sufficient magnitude to degrade transponder performance. This issue is addressed by considering the degradation to a binary phase shift keying (BPSK) signal. A simple model for the electrostatic phenomenon is described, and error probabilities are evaluated. The discharges and induced pulse rates are shown to be well below the interference level.

BPSK modulator using VCCS andresonator without carrier signal and balancemodulator

A new binary-phase-shift-keying (BPSK) modulator is presented. It consists of a voltage control current source (VCCS), an LC resonator and a comparator and is named a switch-resonator BPSK modulator. This type of modulator is simpler than the traditional architectures. The experimental results are also reported; the bit rate and carrier frequency are 2.5 Mbit/s and 5 MHz, respectively.

Direct-sequence spread spectrum in a shadowed Rician fading and land-mobile satellite channel

The performance of a direct-sequence spread-spectrum land-mobile satellite transmission system, using binary phase-shift keying (BPSK) modulation, is analysed. The satellite channel is modeled as having Rician fading characteristics. The bit-error probability is evaluated, considering both the envelope and the phase variation. Assuming a Gaussian approximation for the interference, numerical results are obtained for both spread-spectrum and narrowband land-mobile satellite communication systems with BPSK modulation. A comparison of the two systems is made for light, average, and heavy shadowing. >

Coding to relax laser linewidth requirements and improve receiver sensitivity for coherent optical BPSK communications

BPSK (binary phase-shift keying) modulation with heterodyne demodulation is used in conjunction with convolutional codes to illustrate the feasibility of using coding to relax the laser linewidth requirements and improve the receiver sensitivity. The Viterbi algorithm is used, and the performance of the phase-locked loop in the carrier recovery circuit is studied. The results show that the relaxing factor of the laser linewidth can be larger than 12 at 10/sup -9/ bit error rate when a (2, 1) convolutional code with constraint length 11 is used. When the linewidth is fixed, this code can improve the receiver sensitivity by more than 9 dB.

The Autocorrelation Function of the Output of an N-Level Quantizer with an Angle-Modulated Input Signal

A readily computable formula is given for the autocorrelation function of the output of an arbitrary time-invariant nonlinearity with an arbitrary angle-modulated input. The general result is specialized to the case of an odd-symmetric, but otherwise arbitrary, quantizer. It is shown that to evaluate the output autocorrelation the second-order characteristic function (SOCF) of the modulation is required. Using previously derived SOCFs for a constant, a Gaussian random process, and a generalized random telegraph wave (RTW), the output autocorrelation is given explicitly. Using the SOCF for a binary phase-shift keyed (BPSK) signal, derived here for the first time, the output autocorrelation with BPSK modulation is also presented. Finally, the autocorrelation functions of the modulated input processes are given by reducing the quantizer to a linearity, with the results for the generalized RTW and BPSK modulations being new.