This paper presents the results of discrete bandwidth optimizations used on minimum shift keying (MSK)-type signals. Bandwidth-optimal pulse shaping achieves maximum spectral confinement with respect to given confinement frequencies and given levels of allowable modulated signal envelope nonuniformity. This paper presents a family of design curves defining optimal confinement with respect to confinement frequency and the level of modulated signal amplitude modulation (AM).

This paper evaluates the performance of partial response quadrature modulation techniques using symbol shapes based on the cosine series functions design approach. The baseband quadrature modulation symbol is allowed to spill outside the interval [-T,T] to the interval [-2T,2T]. Spectral efficiency, envelope uniformity, intersymbol interference and probability of error are the performance parameters of interest. Linear and hard-limiting channels are considered. Resulting performance is compared to that of quasi-bandlimited (QBL) signaling introduced by Amoroso (1979) and quadrature overlapped raised cosine (QORC) modulation introduced by Austin and Chang (1981). A simple modulator implementation for a synthesized symbol shape which resembles n=3 QBL is also presented.>

Classical cosine series functions have been applied to the synthesis of finite impulse response filters because of their closed analytic form and low sidelobe levels. It is proposed that cosine series functions be applied to the synthesis of pulse shapes for full response signaling quadrature binary modulation systems in the interest of controlling the spectral characteristics of the resulting modulated signals. Synthesis criteria which govern the selection of cosine series coefficients include provisions for controlling modulated signal envelope nonuniformity and provisions for selecting spectral nulls in the modulated signal. The respective modulation systems are analyzed and compared to conventional modulation techniques QPSK, MSK, SFSK and DSFSK on the basis of modulated signal envelope uniformity and spectral confinement. It is shown that the freedom to select spectral zeroes in the closed form design of the pulse shape introduces a vehicle for suppressing narrowband interference without introducing intersymbol interference into the system. Design examples are provided and modulation system implementations are proposed and discussed.>

It is proposed that classical cosine series window functions be applied to finite symbol duration quadrature binary modulation systems as pulse shapes in the interest of increasing the spectral confinement of the resulting modulated signals. The respective modulation systems are analyzed in terms of modulated signal envelope uniformity, spectral confinement, and bit error rate in the presence of white Gaussian noise with varying degrees of modulated signal amplitude compression. Even in the presence of moderate modulated signal compression, classical cosine series window function pulse shapes offer spectral confinement for quadrature binary modulation systems that is equal to or better than that provided by the conventional pulse shapes corresponding to QPSK, MSK, SFSK, and DSFSK. It is shown that moderate levels of modulated signal compression have negligible effects on the system bit error rate. A system implementation using the sum of FSK modulated signal components to achieve spectral confinement based on the classical cosine series window functions is presented.>

A relatively new rapid coarse acquisition technique is proposed as an alternative to the conventional models currently used in direct sequence spread spectrum (DS-SS) systems. It's comprised of digital components that conform readily to integrated technologies. When nested in a Costas phase locked loop (Costas PLL) the unit generates a pseudo-noise (PN) sequence that is in phase with the incoming sequence (to within one chip). A mathematical description of this algebraic despreader is provided and shown to be consistent with the system's configuration. Simulated test-beds are then developed to measure the despreader's performance in the presence of additive white Gaussian noise (AWGN).>