Abstract: A method and apparatus for improved mobile radio telecommunications employs the transmission of a pilot reference signal within the coherence band of the modulated carrier wave. The receiver in this system uses instantaneous phase estimation techniques of the pilot and carrier received waveforms to provide immunity from phase distortion introduced by the channel.

Abstract: Monitoring of optical amplifiers is accomplished, in accordance with the invention, by an apparatus and method for detecting a power level of a tone modulated upon a signal input to the amplifier, detecting an output power level of the amplifier, and comparing the power level of the tone to the output power level of the amplifier to determine an indication of the performance of the amplifier. In illustrative embodiments of the invention, each of the individual channels within a multiplexed optical signal are modulated with a specific low-frequency tone. The modulating is performed at the transmission site of the optical signal, and the specific tone frequencies are chosen to be lower than the low-frequency cut-off of any other information encoded upon the optical signal. The channel power of each channel is determined after each stage of optical amplification in the network by measuring the power of its respective unique low-frequency tone using a low-cost monitor.

Abstract: In a mobile radio communication system employing a time-division multiple transmission scheme, having a plurality of base stations and a plurality of personal stations, an arbitrary base station, when detecting a pilot signal transmitted from any master base station in the mobile radio communication system, acts as a slave base station which does not transmit its pilot signal but transmits and receives a common control signal to and from a personal station utilizing a frequency channel occupied by the pilot signal. On the other hand, when not receiving the pilot signal, the base station searches for an available frequency channel, and acts as a master base station which transmits its pilot signal on the available frequency channel to occupy the frequency channel, and transmits and receives the common control signal to and from a personal station on that frequency channel.

Abstract: A method and apparatus for a portable communication device, such as a mobile radio terminal in a CDMA network, to identify its geographic location. A communication network comprises multiple base stations which transmit pilot signals, where the pilot signals of one base station are offset from the pilot signals of other base stations by integral multiples of a substantially fixed duration. Associated sync channel messages are also transmitted from which the geographic location of the base stations may be extracted. A portable communication device identifies its location by calculating the delay between the arrival time of a pilot signal from a primary base station and the arrival times of pilot signals from at least two other base stations. For each pair of base stations corresponding to one of the calculated delays, the portable communication device initially specifies its location as being on a selected one of three curves.

Abstract: A method and an apparatus for searching code division multiple access pilot signal energies includes limiting a pilot signal window size above a lower limit and only analyzing search result data corresponding to an instructed pilot signal window size. A central processing unit instructs a searcher receiver within a mobile station modem application specific integrated circuit to search for pilot signal energies within an instructed pilot signal search window unless the instructed pilot signal window size is smaller than a pilot signal window size lower limit. In such a case, the pilot signal search window size is artificially designated as the pilot signal window size lower limit to prevent excessive search completion interrupts from over utilizing central processing unit resources.

Abstract: In a time division multiple access mobile wireless telecommunication system, a base station has a plurality of frequencies with their priority order previously registered in a memory, selects, upon starting the operation, the frequency having the highest priority from frequencies not used by other wireless telecommunication systems, and initiates communications at the selected frequency. The base station also transmits a pilot signal representative of the priority for using the selected frequency in order to prevent other wireless telecommunication system from interrupting to use the frequency.