Abstract: A method for ranging in a wireless communication system and a communication apparatus and/or system using the same are provided. A base station (BS) device includes a terminal grouping unit to group terminals associated with the BS device into a plurality of groups, a radio resource assignment unit to allocate a radio resource assigned to the BS device to each of the plurality of groups, a transmission unit to transmit information about a radio resource assigned to a first group of the plurality of groups to a terminal included in the first group, and a receiving unit to receive a ranging signal from the terminal using the radio resource assigned to the first group, wherein the terminal grouping unit assigns the terminal to be included in a second group of the plurality of groups where the ranging signal is not received by the receiving unit.

Abstract: A method for ranging in a wireless communication system and a communication apparatus and/or system using the same are provided. A base station (BS) device includes a terminal grouping unit to group terminals associated with the BS device into a plurality of groups, a radio resource assignment unit to allocate a radio resource assigned to the BS device to each of the plurality of groups, a transmission unit to transmit information about a radio resource assigned to a first group of the plurality of groups to a terminal included in the first group, and a receiving unit to receive a ranging signal from the terminal using the radio resource assigned to the first group, wherein the terminal grouping unit assigns the terminal to be included in a second group of the plurality of groups where the ranging signal is not received by the receiving unit.

Abstract: A radio communication system receiver employs a demodulator (104) to recover a received signal. The receiver of the present invention further includes a channel quality estimator (222) for estimating a characteristic of the communication channel over which the signal is received. A first or second decoding technique (220) is selectively employed using the estimated communication channel quality value (223). In this manner, an improved receiver is provided that is able to realize the benefits of either the first or the second decoding technique, depending the channel condition.

Abstract: Variable hangover time is provided for a speech coder (105). Voice activity within a speech message is detected (209) using a voice activity detector (VAD) (107), and a signal-to-noise ratio is calculated. A variable hangover time is calculated (215) and appended to the time in which voice activity is detected, producing an extended voice detection period. The speech coder (105) is enabled only during the extended voice detection period, thus saving power.

Abstract: A convolutional decoder which assigns bit metrics to at least one bit of a symbol in a multilevel system. This decoder uses soft-decision Viterbi decoding with channel state information of a convolutionally-encoded communication transmitted using multilevel modulation.

Abstract: A harmonic signal is created from a limited spectral representation of a voice signal. The harmonic signal is combined with the at least a portion of the limited delayed spectral signal to provide a reconstructed speech signal having perceptually improved audio quality.

Abstract: An subband coding system encoder is provided for improving the quality of a reconstructed speech signal. Briefly, the improved subband coding system encoder includes means for improving the selection of the waveform/noise fill gain factor. The improved selection method, according to the invention, is based on the quasi-stationary characteristic of speech, that is, that the short-time frequency spectrum of a speech signal varies slowly with time. Moreover, the amount of fill energy is adaptively determined for each subband according to the shape of the frequency spectrum for each speech frame.

Abstract: A communication system that provides TDM and FDM communications between communication units. At least two control slots are provided in each TDM frame window to provide communication control information such as channel assignment information.