Abstract: A compression/decompression method useful in communicating ideographic characters to communication devices. An ideographic character is represented by a compressed character codeword including information defining a structure type or layout of the character, together with primitive types that represent combinations of simple graphical elements. A character generator read-only memory (CGROM) (20) includes a compressed character codeword database (22) and a primitive type database (24). Character codes corresponding to a compressed character codeword are transmitted to a communication device (600), such as a selective call receiver. The communication device (600) includes a microprocessor/controller (50) that decompresses the compressed character codewords corresponding to the character codes based on the data stored in the character database (22) and the primitive type database (24).

Abstract: A central controller (10) controls the operation of a code division multiple access (CDMA), spread spectrum communication system, which includes base stations (15) and portable transceivers (20) for communicating with the base stations (15). The central controller (10) stores a plurality of seeds, which are used by the portable transceivers (20) in generating pseudo-noise (PN) sequences, and, in response to requests from base stations (15), the central controller (10) distributes at least a portion of the assignable seeds to each of the requesting base stations (15). The base stations (15) that have received seeds from the central controller (10) subsequently transmit the seeds over the air to the portable transceivers (20) within their respective coverage areas. The portable transceivers (20) then utilize the seeds to generate spread spectrum signals for reception by a closest base station (15) having a coverage area in which they are located.

Abstract: A base station (15) for receiving and processing a spread spectrum signal includes a memory (520) for storing the spread spectrum signal and a processor (525) coupled to the memory (520) for processing the spread spectrum signal to decode information included therein and for determining an information type. Timing circuitry (555, 560, 565) coupled to the memory (520) and the processor (525) generates a time value indicative of a reception time of the spread spectrum signal, wherein the time value is stored in the memory (520) when the information type is determined to correspond to a communication initiation signal.

Abstract: A method for receiving and processing data in a portable transceiver (20) comprises the steps of receiving (320) at least one information signal and decoding (325) the at least one information signal to recover information included therein. The method further comprises the steps of generating (345) a pseudo-noise (PN) sequence in accordance with the information.

Abstract: A base station for processing a received and stored spread spectrum signal determines the signal strengths of a first plurality of signals included in the stored spread spectrum signal. The strongest signal of the first plurality is subtracted from the stored signal such that the stored signal is replaced in the memory by a modified spread spectrum signal including a second plurality of signals. The base station determines signal strengths of the second plurality of signals, then subtracts the strongest of the second plurality from the modified spread spectrum signal.

Abstract: A monolithic crystal filter formed by a multi-section piezoelectric resonator having anodizable electrodes is subjected to plasma from a low energy oxygen glow device to adjust the frequency response. The electrodes are selectively connected to potentials whereby the electrodes are individually anodized to increase the density thereof and change the frequency response of the resonator. The glow device includes anode and cathode rings separated by an insulator ring which holds a cathode screen across the cathode. The anode ring has a concave face and the inside diameter is generally the same as the diameter of the resonator so that the resonator can be placed close to the anode and plasma is localized on the resonator electrodes. The electrodes are connected in a frequency measuring circuit so that the response is monitored and the extent of anodization of the individual electrodes is controlled.