During the 1980's, many improvements will be made in the Air Force's ability to communicate in a battlefield environment. Programs like JTIDS, SEEK TALK, TRI-TAC, and the Ground Mobile Forces satellite communications terminals will improve the security, jam resistance, connectivity, and capacity of today's Air Force tactical communications. Even after these programs have been implemented, however, some important problem areas will remain, especially in our ability to resist a determined enemy's electronic warfare and physical attacks. This paper first describes today's Air Force tactical communications requirements and capabilities, and then summarizes the current problem areas. Currently planned programs to solve these problems are described for aircraft voice, aircraft data, ground-to-ground interconnections, and sensor/weapon data links. The problem areas that will remain after the implementation of these programs are then discussed. Some important technological opportunities are identified that hold promise for overcoming some of the projected problem areas in the 1990's. In addition, some system approaches are suggested for exploiting these technological opportunities, and for improving our use of older technologies. These system approaches emphasize reduced-information-rate operation, adaptive network techniques, network management/control, packet switching, and joint-Service, interoperable, common-user systems.

This paper describes the application of the solenoid array principle to the problem of word recognition, code recognition, and (in a limited sense), associative memory. The proposed device, based entirely on existing experience with a large character recognition cross correlator, is capable of recognizing one of 24,000 individual English words up to 16 letters long. The simultaneous correlation and selection is made in less than 3 μsec, and cycle time of the device is less than 20 μsec. The selection can be made either on a perfect-match or a best-match basis. The parameters of the system proposed are taken as typical practical ones and direct expansion of the correlator to a capacity in excess of 100,000 words is fully feasible.

A new semipermanent data-storage technique is described which can be used either as a fast multimegabit correlator or as a high-speed digital memory. It consists of an array of long, thin cylindrical solenoids and printed-circuit data planes perpendicular to these solenoids and magnetically coupled to them. Data is stored on the planes in terms of circuit paths which either enclose (1) or bypass (0) each solenoid. Data entry is achieved automatically by passing the planes through a gang punch which severs the unwanted parts of the circuit path. Planes may be easily removed individually or together in stacks. No sense or drive elements are interleaved with the data planes, so that the stack is an integral unit. Depending upon the application, either the solenoids or the planes are driven. As a correlator, the solenoids are driven in proportion to the cell strength of the input pattern, and an analog output appears simultaneously on each of the N data planes, where N is the number of stored signals or patterns ranging as high as 2000. Correlation time is less than 3 μsec in the current model, whose planes contain 1428 bits each. As a digital memory, the aforementioned solenoid-drive, plane-output configuration may be used, or the planes may be driven and data outputs taken from the solenoids. The memory is random access and address organized, with a cycle time of about 1 μsec, depending on memory size.

Relationships are derived showing that the optimum processor for a process that has been transformed by a memoryless nonlinear device is of the same form as that for the original untransformed process if we replace the measured values of the process by their inversely transformed values.

Canonical forms and circuit structures are derived for Bayes' optimum decision rules utilizing Wiener-like functionals. The formalism is valid for loss functions whose derivatives with respect to the estimates exist, (L_2over the space of unknowns ), The structures derived consist of orthonormal filter sets (usually Laguerre filters ) followed by combinations of\nu^{th}-law-devices (Hermite polynomial generators of the Laguerre coefficients), amplifiers of specified gains, and then summing and division circuits. The amplifier gains can be partially preadjusted via a sample of the observable and unknown or by a pre-computation; the remainder of the gain adjustment is, in the general case, obtained via feedback through a function generator. If the gains are adjusted via the first method, ergodicity is required and self-adaptive features are implied. As a first step in the exposition, analogous canonical forms and structures, where the past of the observable is characterized by its time-samp]es rather than by its Iaguerre coefficients, are obtained. The derivation does not stop here because of the limitations of the description, analysis, and equipment-realization of a stochastic process in terms of a finite number of its time samples. The advantage of the structural forms derived over previous ones is that they are formally valid for all values of signal-to-noise ratio and are always physically realizable and time-invariant whereas this has not usually been true in the past. Several examples of structures are given. Existence and convergence problems are discussed in the appendices. Perhaps more important than the explicit results obtained here are the implications involved in the procedure. The fact that expansions of the probability measures for a significant class of stochastic processes has been obtained in terms of canonical expansions of the Wiener process is felt to be a major accomplishment.