Abstract: An optimum signal is assembled from a set of data streams originating from a transmitter. Corresponding bits of the data streams are compared, and for each set of corresponding bits, an output bit is selected based on a majority vote of the data streams. If a majority vote does not yield a result, an output bit can be selected from a default stream, or from a stream which yielded a preceding output bit. Data streams having a signal quality below a predetermined limit are disregarded for purposes of conducting the majority vote. The output stream therefore includes bits taken from different data streams and different times, and has a quality greater than is achievable by any one of the original data streams.

Abstract: An electronic tour guide overcomes the monotony of an automobile trip. The system includes a GPS receiver, a computer, and a database of pre-recorded information. These components may be contained in one housing, and may be permanently installed in a vehicle. The database contains information pertaining to various geographical regions. The computer receives a signal from the GPS indicating the position of the vehicle. The computer then retrieves information from the database, the retrieved information corresponding to the position determined by the GPS receiver. The information is presented to the traveler, either on a video display or through an audio playback unit. The system can therefore provide information on the history, geography, and/or culture, relating to the region through which the vehicle is traveling. The information can be modified to include specific reference to points of interest with respect to the instantaneous position and orientation of the vehicle.

Abstract: In a preferred embodiment, a computer is employed to control the system. The system initially accepts analog signals and converts them into digital signals, which are then compressed, at a DPCM encoder, into a three bit code. Thereafter the once compressed signals are further compressed in accordance with a variable length code. The twice compressed digital signals are transmitted through formatter circuitry whereat a tag is added to indicate (in addition to other information) what forms of compression have been employed on the digital signals which follow the tag. The twice compressed and tagged digital signals are forwarded to a buffer storage device. The role of the buffer storage is to keep a relatively constant supply of data signals so that there is a relatively constant supply of pels moving to the transmitter at a constant frequency. The computer monitors the buffer fullness and the rate at which it is being loaded or is emptying.