Abstract: A point-to-multipoint communication system wherein the base station broadcasts the same frequency band signals over multiple sectors of given node. The base station includes a plurality of channel receivers (ch. 1-ch. n) for each sector and a plurality of antennas 36a and 36b selectively coupled to said channel receivers. The subsector antennas have these radiation centers offset from each other to present different coverage over the node.

Abstract: A Global Position System (GPS) receiver is disclosed which includes an RF converter and quadrature digitizer implemented in hardware and a signal processor including a computer, code generator and preprocessor. The preprocessor has a divide by 1,2,3 divider for controlling the code generator so as to provide I,Q early, prompt and late digital signals of 0.5 chip separations to the computer for tracking code phase, carrier phase/frequency and signal amplitude. This structure eliminates the need for numerically controlled oscillators implemented in hardware while maintaining accurate performance.

Abstract: A multiple block binary synchronous duplex communications system provides for the orderly transfer of data from one location to another utilizing communications facilities. This communications system increases the efficiency of data links with long propagation delays or with long processing times at either end by maintaining a continuous flow of data and responses in both directions. The memory of the communications link is kept full at all times. Data is transmitted in blocks including an identification code. The received data is checked for errors. When errors occur the transmission of data is not stopped; data is continuously transmitted and signals are returned including the block identification of the block containing the error. The block containing the error is then retransmitted when the transmitting station of the communications system is available for this task.