Abstract: A complex baseband model of the power amplifier within a DSP domain is used to develop a feedback signal that would be equivalent to the optimum negative feedback used for the analog amplifier. Once the feedback signal is available, it can be processed to compensate for the effects of the group delay and for optimum loop gain, hence resulting in a broadband response with no theoretical limitations on the linearization of the amplifier.

Abstract: Apparatus for locating a mobile phone in a cellular phone system, in which the cellular phone system comprises plural base stations, each base station being associated with a cell, and in which the mobile phone is programmed to communicate signal strength of received signals to the base stations. Each base station, has a processing unit operably connected to the plural base stations by first communications links, the processing unit having as input the received signal strength measurements, the processing unit being programmed to operate upon the received signal strength measurements to solve a channel model equation in which the position of the mobile phone and the path loss exponent of the cell are unknowns and produce as output position location signals representing the position of the mobile phone in the cell, and a user interface operably connected to the processing unit by a second communication link for communicating signals indicative of the position of the mobile phone in the cell.

Abstract: In a word clustering apparatus for clustering words, a plurality of words is clustered to obtain a total tree diagram of a word dictionary representing a word clustering result, where the total tree diagram includes tree diagrams of an upper layer, a middle layer and a lower layer. In a speech recognition apparatus, a microphone converts an input utterance speech composed of a plurality of words into a speech signal, and a feature extractor extracts predetermined acoustic feature parameters from the converted speech signal. Then, a speech recognition controller executes a speech recognition process on the extracted acoustic feature parameters with reference to a predetermined Hidden Markov Model and the obtained total tree diagram of the word dictionary, and outputs a result of the speech recognition.