Abstract:
A method and apparatus for providing power control can be used in a mobile communication system having at least one mobile station (12) communicating over forward and reverse channels with at least one base station (16), and a base station controller (14) coupled to the base station (16). The mobile station (12) sends frame quality or error messages indicating a quality of the forward channel received from the base station (16). The base station (16) receives these messages and routes to the base station controller (14). In response to these messages, the base station determines a transmission power level of the signals transmitted therefrom to the mobile station (12). The base station controller (14), also in response to these messages, determines a correct transmission power level of the signals transmitted from the base station to the mobile station (12), and sends commands indicative of the power level to the base station (16). The base station (16) in turn then adjusts the power of its forward channel transmission signals to the mobile station (12) in response to these commands from the base station controller (14).
Abstract:
Method and apparatus for selecting a code vector in an algebraic codebook wherein the analysis window for the coder is extended beyond the length of the target speech frame. An input signal is filtered by a perceptual weighting filter (76). Then, the filter is set to ring out for a number of samples equal to the length of the perceptual weighting filter (76), while a zero input vector is applied as input. By extending the analysis window, the two dimensional impulse response matrix can be stored as a one dimensional autocorrelation matrix in memory (60, 80), greatly saving on the computational complexity and memory required for the search.
Abstract:
A method and apparatus to prevent system deadlock in a dispatch system by monitoring link activity is described. The dispatch system is comprised of a set of remote units (10, 20, 22) which communicate with each other by broadcasting one at a time to the group. A remote unit (10) communicates with the other remote units through at least one base station (44). A communications manager (40) grants a remote unit (10) to be the exclusive system talker upon request through the base station servicing the requesting remote unit (44). The base station (44) monitors a series of data from the remote unit designated as the system talker (10) to detect voice activity. The base station (44) sends a surrogate request to the communications manager (40) to relinquish the system talker privilege if the voice activity falls below a predetermined threshold.
Abstract:
A method and apparatus for high rate CDMA wireless communication in which a set of individually gain adjusted subscriber channels are formed via the use of a set of orthogonal subchannel codes (Wi) having a small number of PN spreading chips per orthogonal waveform period. Data to be transmitted via one of the transmit channels is low code rate error correction encoded (134) and sequence repeated before being modulated with one of the subchannel codes, gain adjusted (152, 154, 156, 158), and summed (160) with data modulated using the other subchannel codes. The resulting summed data is modulated using a user long code and a pseudorandom spreading code (PN code) and upconverted for transmission.
Abstract:
A coupled multi-segment helical antenna is provided having a length that is shorter than otherwise obtainable for a conventional half-wavelength antenna. The coupled multi-segment helical antenna includes a radiator portion (800) having a plurality of helically wound radiators (804) extending from one end (832) of the radiator portion to the other end (834) of the radiator portion (800). Each radiator (804) is made up of a set of two or more segments (708, 710). A first segment (708) extends in a helical fashion from the first end (832) of the radiator portion (800) toward the second end (834) of the radiator portion. The second segment (710) extends in a helical fashion from the second end (834) of the radiator portion (800) toward the first end (832) of the radiator portion, wherein a portion of said first radiator segment (708) is in proximity with a portion of said second radiator segment (710) such that said first and second radiator segements (708, 710) are electromagnetically coupled to one another.
Abstract:
A system and method for controlling the strength of a shared resource signal transmitted by the satellite transponder (104) in a satellite communications system. The satellite communications system includes a gateway (102) for transmitting communications signals including a shared resource signal (402), a satellite transponder (104) for relaying (404) the signals to at least one subscriber unit (106A, B, C) (for example, a phone), and at least one subscriber unit (106) for receiving the signals (406). The method includes the steps of receiving the shared resource signal (406), at each subscriber unit (106), via the satellite transponder (104); measuring (408), at each subscriber unit (106), a signal strength for the received shared resource signal; sending the signal strengths to the gateway (410, 102); and adjusting the power of the shared resource signal transmitted by the satellite transponder (418) based on the signal strengths.
Abstract:
A novel and improved antenna coupler (100) useful in an adapter for a portable radiotelephone (200). In a first embodiment, a plurality of curved bands (204a-204c) of metal are positioned on a ground plane (102), with at least one of the plurality of curved bands of metal (204a-204c) being electrically isolated from the ground plane (102) so as to couple RF signals to and from the antenna (204) of a portable telephone (200). At least one ground pin (206a, 206b, 206c) is also mounted on the ground plane (102). When a portable radiotelephone (200) is interfaced with the antenna coupler (100), the at least one ground pin (206a, 206b, 206c) makes electrical contact with assembly screws (202a, 202b) or an external ground pad (208) of a battery charging port on the portable radiotelephone (200). In a second embodiment, a coupling pin (404) makes direct contact with a component of the RF chain of the portable radiotelephone (200). In a third embodiment, a helical coupler (504) surrounds the antenna (204) of the portable radiotelephone (200).
Abstract:
A novel and improved method and apparatus for signal acquisition in a wireless telecommunication system having large transmission delay uncertainty is described. A terminal (106) first acquires the forward link signal (102) from a hub (100) and extracts timing information from that forward link signal (102). Using the timing information the terminal (106) estimates the time at which a next search window (212) takes place during an access slot (214), and the time and pseudorandom code state necessary to transmit an access probe (205) so as to arrive at during the search window (212) assuming the terminal (106) is located a maximum distance from the hub (100). The terminal (106) proceeds to transmit additional access probes at times occurring one access slot period plus a delta time interval (220) after the previous transmission. The delta time interval (220) has a duration less than that of a search window associated with each access slot. Each access probe (205) is processed with various transmission codes the states of which are incremented by an access slot period for each access probe transmitted.