Abstract: A method and apparatus for providing a reliable means to perform handoff from a code division multiple access (CDMA) system using a pilot signal to an alternative access technique system. Simple pilot box circuitry is added to a set of border base stations. The border base stations are base stations which operate only in the alternative access technique and which have coverage areas which are contiguous with coverage areas of CDMA operation base stations. The mobile unit monitors for the pilot signal from the border base stations in the same manner as it monitors for pilot signals from the CDMA operation base stations. When the mobile unit detects the pilot signal corresponding to a border base station, it notifies a system controller in accordance with standard operation. The system controller is aware that the pilot signal corresponds to a border base station and thus triggers a hard handoff process to the alternative access technique system in response thereto.

Abstract: In a code division multiple access (CDMA) spread spectrum cellular communication system in which a mobile station user communicates with another system user via at least one base station, wherein each base station transmits a common pilot signal of a different code phase with respect to other base stations in said system, a method for directing communications between said mobile station user and said base stations. The mobile station monitors the signal strength of pilots and reports the measured signal strength to a system controller via the base station through which it is communicating. Command messages from the system controller to a new base station and the mobiles station establishes communication through the new base station in addition to the communication through the current base station.

Abstract: A method and apparatus providing softer handoff of a mobile unit between sectors of a common base station. A sectorized base station comprises a set of demodulation elements. Each demodulation element may be assigned to a signal from one of a plurality of sectors. The output of the demodulators are combined before the decoding process independent of the sector from which the data originated. This configuration provides improved output data reliability, more stable power control, and more efficient use of resources at the base station.

Abstract: A method and system for providing a reliable means to perform handoff from a code division multiple access (CDMA) system using a pilot signal to an alternative access communication technique system. Simple pilot box circuitry is added to a set of border base stations. The border base stations are base stations which operate only in the alternative access communication technique and which have coverage areas which are contiguous with coverage areas of CDMA operation base stations. The mobile unit monitors for the pilot signal from the border base stations in the same manner as it monitors for pilot signals from the CDMA operation base stations. When the mobile unit detects the pilot signal corresponding to a border base station, it notifies a system controller in accordance with standard operation. The system controller is aware that the pilot signal corresponds to a border base station and thus triggers a hard handoff process to the alternative access communication technique system in response thereto.

Abstract: An apparatus and method for adding and removing a target base station from a network of base stations, which includes base stations adjacent the target base station. The apparatus is comprised of two attenuators: a first for setting an artificial receive noise power level and a second for setting a transmit level. The transmit level determines the forward link coverage area of the base station. The artificial noise level sets the reverse link coverage area of the base station when a base station is added, initially the transmit power is low and the artificial receive noise power is high such that the forward and reverse kink coverage areas are collocated in close proximity to the base station. As the base station blossoms into full operation, the artificial receive noise power is decreased and the transmit level is increased such that the two coverage areas of the base station remain balanced as the coverage areas expand.

Abstract: A method and apparatus for matching the location of the forward link handoff boundary to the reverse link handoff boundary. A system constant is chosen which defines the product of the received power and the transmitted pilot power at every base station. The reverse link power level is measured at the base station and the forward link power level is compensated for the reverse link loading to maintain the constant product. Thereby the forward link handoff boundary to the reverse link handoff boundary are aligned to the same location.

Abstract: Collisions between messages simultaneously transmitted by multiple spread-spectrum transmitters are reduced by distributing the transmissions over the available resources of the receiver. The transmitters may be mobile stations and the receiver may be a base station in a CDMA cellular telephone system. Each mobile station uses one or more randomization methods to distribute its transmissions. In the first randomization, the mobile station time--delays its transmissions by a number of chips of the PN code with which it spreads the transmitted signal. A hash function produces the number from an identification number uniquely associated with that mobile station. In a second randomization, the mobile station randomly selects the PN code. In a third randomization, the mobile station inserts a random delay between successive message transmissions or probes if it does not receive an acknowledgement after a predetermined timeout period. A predetermined number of such transmissions is called a probe sequence.

Abstract: A method and apparatus for arranging various types of data, and at various rates, into a uniquely structured format for transmission. Data for transmission formatting may be vocoder data or different types of non-vocoder data. The data organized into frames of a predetermined time duration for transmission. The data frames are organized, depending on the data, to be at one of several data rates. Vocoder data is provided at one of several data rates and is organized in the frame according to a predetermined format. Frames may be formatted with a sharing of vocoder data with non-vocoder data to be at a highest frame data rate. Different types of non-vocoder data may be organized so as to also be at the highest frame data rate. Additional control data may be provided within the data frames to support various aspects of the transmission and recovery upon reception.

Abstract: A system for reducing receiver power consumption in communication system having a transmitter and one or more receivers schedules periodic messages in "slots." Each receiver is assigned a slot during which it monitors the transmissions. The transmitter transmits messages to the receiver only during the assigned slots. The receiver is in an "active state" during its assigned slot. It may remain in the active state after its assigned slot if the message requires the receiver to perform additional actions. During the "inactive state," which is the time period between successive occurrences of its assigned slot, the receiver may perform any action not requiring coordination with the transmitter. It may conserve power during this time by removing power from one or more components such as those used for monitoring the transmissions. At a time during the inactive state shortly before the assigned slot, the receiver applies power to these components and performs initializations.

Abstract: An method and apparatus for computing a scalar projection of a vector onto another vector. The apparatus comprises a multiplying circuit and a summing circuit. The multiplying circuit is for multiplying a value representative of a first component of a first vector with a value representative of a first component of a second vector to provide a first intermediate value, and for multiplying a value representative of a second component of a first vector with a value representative of a second component of a second vector to provide a second intermediate value. The summing circuit sums the first and second intermediate values to provide a resultant value representative of the scalar projection of the first vector onto the second vector. The apparatus may further comprise a storing circuit and a selection circuit. The storing circuit is for storing the values representative of the first and second components of the first vector, and the values representative of the first and second components of the second vector.

Abstract: In a digital communication system in which digital data is transmitted in data frames of a preselected time duration, a method and apparatus for formatting digital data in each data frame. A set of data bits of a first data type having a bit count corresponding to one of a plurality of predetermined bit counts are provided. A set of parity check bits for the set of data bits of said first data type are generated when the bit count is a highest bit count or a next to highest bit count. A set of tail bits is generated in accordance with a predetermined frame termination format. In respective order the set of data bits of the first data type, the parity check bits, and the tail bits are porovided in a data frame if the bit count is of the highest bit count or of the next to highest bit count. Otherwise, the set of data bits of the first data type and the tail bits are provided in respective order in the data frame.

Abstract: In a receiver having a plurality of demodulation elements, a method of assigning the plurality of demodulation element so a set of available signals. A first method emphasizes diversity of transmitting devices so that power control is optimal. A second method emphasizes the maximum signal strength available to produce aggregate maximum signal strength. Both methods control the number of reassignments so that excessive data is not lost during the reassignment process. The apparatus comprises the plurality of demodulation elements, at least one searcher element, and a controller.

Abstract: A power control system for a cellular mobile telephone system in which system users communicate information signals between one another via at least one cell site using code division multiple access spread spectrum communication signals. The power control system controls transmission signal power for each cellular mobile telephone in the cellular mobile telephone system wherein each cellular mobile telephone has an antenna, transmitter and receiver and each cell-site also has an antenna, transmitter and receiver. Cell-site transmitted signal power is measured as received at the mobile unit. Transmitter power is adjusted at the mobile unit in an opposite manner with respect to increases and decreases in received signal power. A power control feedback scheme may also be utilized. At the cell-site communicating with the mobile unit, the mobile unit transmitted power is measured as received at the cell-site.

Abstract: An apparatus and method for adding and removing a target base station from a network of base stations, which includes base stations adjacent the target base station. The apparatus is comprised of two attenuators: a first for setting an artificial receive noise power level and a second for setting a transmit level. The transmit level determines the forward link coverage area of the base station. The artificial noise level sets the reverse link coverage area of the base station. When a base station is added, initially the transmit power is low and the artificial receive noise power is high such that the forward and reverse link coverage areas are collocated in close proximity to the base station. As the base station blossoms into full operation, the artificial receive noise power is decreased and the transmit level is increased such that the two coverage areas of the base station remain balanced as the coverage areas expand.

Abstract: A system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance. With orthogonal PN codes, the cross-correlation is zero over a predetermined time interval, resulting in no interference between the orthogonal codes, provided only that the code time frames are time aligned with each other. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. In the cell-to-mobile link, pilot, sync, paging and voice channels are defined. Information communicated on the cell-to-mobile link channels are, in general, encoded, interleaved, hi-phase shift key (BPSK) modulated with orthogonal covering of each BPSK symbol along with quadrature phase shift key (QPSK) spreading of the covered symbols.

Abstract: A system for reducing receiver power consumption in communication system having a transmitter and one or more receivers schedules periodic messages in "slots." Each receiver is assigned a slot during which it monitors the transmissions. The transmitter transmits messages to the receiver only during the assigned slots. The receiver is in an "active state" during its assigned slot. It may remain in the active state after its assigned slot if the message requires the receiver to perform additional actions. During the "inactive state," which is the time period between successive occurrences of its assigned slot, the receiver may perform any action not requiring coordination with the transmitter. It may conserve power during this time by removing power from one or more components such as those used for monitoring the transmissions. At a time during the inactive state shortly before the assigned slot, the receiver applies power to these components and performs initializations.

Abstract: A system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance. With orthogonal PN codes, the cross-correlation is zero over a predetermined time interval, resulting in no interference between the orthogonal codes, provided only that the code time frames are time aligned with each other. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. In the cell-to-mobile link, pilot, sync, paging and voice channels are defined. Information communicated on the cell-to-mobile link channels are, in general, encoded, interleaved, bi-phase shift key (BPSK) modulated with orthogonal covering of each BPSK symbol along with quadrature phase shift key (QPSK) spreading of the covered symbols.

Abstract: In a code division multiple access (CDMA) spread spectrum cellular communication system in which a mobile station user communicates with another system user via at least one base station, wherein each base station transmits a common pilot signal of a different code phase with respect to other base stations in said system, a method for directing communications between said mobile station user and said base stations. The mobile station monitors the signal strength of pilots and reports the measured signal strength to a system controller via the base station through which it is communicating. Command messages from the system controller to a new base station and the mobiles station establishes communication through the new base station in addition to the communication through the current base station.

Abstract: A power control system for a cellular mobile telephone system in which system users communicate information signals between one another via at least one cell site using code division multiple access spread spectrum communication signals. The power control system controls transmission signal power for each cellular mobile telephone in the cellular mobile telephone system wherein each cellular mobile telephone has an antenna, transmitter and receiver and each cell-site also has an antenna, transmitter and receiver. Cell-site transmitted signal power is measured as received at the mobile unit. Transmitter power is adjusted at the mobile unit in an opposite manner with respect to increases and decreases in received signal power. A power control feedback scheme may also be utilized. At the cell-site communicating with the mobile unit, the mobile unit transmitted power is measured as received at the cell-site.

Abstract: A maximal length linear sequence pseudorandom noise (PN) sequence generator for generating an augmented length PN sequence of length 2.sup.N. The PN generator includes circuitry for generating a PN sequence of length 2.sup.N -1 chips. A sequence augmenting circuit is included which inserts at least one additional chip in the PN sequence at a predetermined position within the PN sequence so as to provide an output of an augmented PN sequence of length 2.sup.N chips. The generator may also include sequence shifting circuitry which is responsive to a mask input for providing a predetermined shift in the output augmented PN sequence without incurring a transition period where the shifted output is invalid.