The traditional study of reproducing systems involves the Gabor and wavelet systems. Gabor systems are generated by the action of translations and modulations on a single or finite family of functions in L^2(R) or L^2(R^d). The wavelet systems are reproduced by the actions of dilations and translations. Improving and extending these notions, it is natural to construct a systems combining the actions of translations, modulations and dilations on a single or finite family of functions in L^2(R) or L^2(R^d). This systems known as Wave Packet Systems. In this paper after introducing these systems in details and reviewing the frameness of theses systems, we present a condition under which the wave packet system {DajTkbEmcϕ}j,m,k∈Z is a frame for L^2(R) and we show that there is a large class of parameters and functions that cannot generate a Bessel sequence.
