Abstract: Location of a remote unit within a wireless communication system is determined by utilizing an Amplitude Difference-based Angle Of Arrival estimation (AD-AOA). In particular, a prompt ray (401) from a signal (117) having undergone multi-path scattering is received at multiple antennas (103 and 105). The prompt rays (401) received at each antenna are combined by a signal combiner and averager (307). The signal combiner and averager (307) then averages the energy of the summed prompt ray over multiple power control groups to determine an accurate energy level for the summed prompt ray. The averaged energy value for the summed prompt ray is then output to an AOA computer (309), along with the average energy value for summed prompt rays at other sectors. The energy values for the summed prompt rays received from each sector are analyzed to determine an appropriate angle of arrival.

Abstract: A method for transmitting a communication signal (20) having a data rate over a plurality of spread spectrum traffic channels includes determining a first number of traffic channels required to transmit the communication signal at the data rate, and determining a second number of traffic channels (502) available for transmitting the communication signal (20). In response to a comparison of the first number of traffic channels to the second number of traffic channels, a first traffic channel (54) for transmitting a first portion of the communication signal (50, 51) and a second traffic channel (56) for transmitting a second portion of the communication signal (52, 53) are selected from the. second number of traffic channels (502). The selection of the first traffic channel (54) is non deterministic of the selection of the second traffic channel (56).

Abstract: Power control in a spread spectrum communication system takes place by determining a speed of a remote unit (405) and assigning as a power-control threshold a target threshold based on the determined speed (410). An instantaneous threshold value is created (415) based on frame-quality information and the target threshold. An energy of a power-control group transmitted (430) from a remote unit is compared to the instantaneous threshold value and a power-adjustment command is determined. The power-adjustment command is transmitted to the remote unit instructing the remote unit to adjust its power accordingly.

Abstract: Reverse channel power control in a CDMA system is accomplished by measuring a power-control group transmitted from a remote unit (403) and determining a transmission time of a next power-control bit. The measurement of the power-control group is discontinued (405) based on the transmission time of the power-control bit and a round trip delay between the base station and the remote unit in order to transmit the power-control bit (419) to the remote unit in the next time slot.

Abstract: A method of communication handover from a first communication entity (33) to a second communication entity (43) in a communication system (10) where a communication unit (80), communicating with a transceiver (23) associated with the second communication entity, is linked to the first communication entity. The invention provides for establishing a communication link between the communication unit and the second communication entity while maintaining a communication link between the communication unit and the first communication entitiy. Then, communications are substantially simultaneously transfered to the second communication entity while terminated from the first communication entity.

Abstract: A method and apparatus is provided for facilitating coherent communication reception. A received reference symbol coded spread spectrum communication signal is despread with a spreading code to derive a stream of reference samples and a stream of data samples. The channel response is estimated by utilizing the stream of reference samples. An offset frequency detector determines an offset to be applied to the received signal via a frequency locked loop, while a timing control compensates for slow timing drift and fast fading based on power estimates derived from the stream of reference samples and/or the stream of data samples. A slot detector controls gates which optimize the timing control and frequency offset detector outputs from the various timing branches. Thus an improved detection of estimated data symbols from the stream of received data samples is provided.

Abstract: A method and apparatus for improved offset frequency estimation includes in a first embodiment a receiver (100) for coherent reception of a signal having known reference information, the receiver including an extractor (106) for extracting the reference information (107) from the signal, and an offset frequency estimator (110). The offset frequency estimator (110) includes a filter (121) for filtering the reference information and outputting a filtered reference sequence; a correlator (122, 124) for correlating the filtered reference sequence against a predetermined reference signal to form correlation values; and a peak detector (126) for determining an offset frequency estimate (131) from the correlation values. Other embodiments are also shown.

Abstract: A communication system (100) employs a method (600) and apparatus (101) for conveying a communication signal between a communication unit (105) and a base site (101) that services a sectorized coverage area (103). The communication unit (105) transmits an uplink communication signal (113) to the base site (101). The base site (101) receives (603) the uplink communication signal (113) and determines (605) an approximate location of the communication unit (101) within a first portion (111) of a sector (108) of the sectorized coverage area (103). A downlink communication signal is then transmitted (609, 613) to the communication unit (105) based on the approximate location of the communication unit (105) using an antenna structure that produces a beamwidth (117) narrower than an angular width of the sector (108).

Abstract: A method, performed by a mobile station (119), prevents an active call from being dropped when the mobile station (119) suddenly transitions from a first coverage area (121) to a second coverage area (122) in a code division multiple access (CDMA) cellular radiotelephone system (100). The active call is determined (601) to be in danger of being dropped responsive to the mobile station (119) suddenly transitioning from the first coverage area (121) to the second coverage area (122). The first base station (115) is notified (602) that the active call is in danger of being dropped responsive to the step of determining (601). The active call with the first base station (115) is determined (603) to be in the process of being dropped responsive to the step of notifying (602). The active call is established (604) with the second base station (116) in the second coverage area (122) before the active call with the first base station (115) is dropped responsive to the step of determining (603).

Abstract: The power of a first signal is measured and is compared with a threshold. If the first signal power meets a handoff threshold, the system enters the handoff procedure. Once in the handoff procedure, estimates of a first signal quality a signal would have, if transmitted from the first site to the subscriber, and a second signal quality a signal would have, if transmitted from the second site to the subscriber, are determined. If the estimated first signal quality meets a transmit threshold, the first will activate a traffic signal to the subscriber. If the estimated first or second signal quality fails to meet the transmit threshold, the first or second, respectively, will terminate its traffic signal to the subscriber, but the transmission resources will remain dedicated to the subscriber. If the estimated first or second signal quality fails to meet the handoff threshold, the first or second, respectively, will discontinue serving the subscriber.

Abstract: A system is offered of increasing signal quality within a cellular communication system through the use of directional antennas and random assignment of communication resources.

Abstract: A coherent reverse channel, a per-chip spreading function, orthogonal spreading functions and a time alignment of all traffic channels are implemented such that the main signal of each channel arrives at a base-station within a fraction of a chip of one another in accordance with the invention. With this, the orthogonality among all channels is maintained, and, when demodulated, all channels except the channel of interest provides a cross-correlation of substantially zero with respect to the remaining signals.

Abstract: A method of reducing interference within a cellular system (10) by partitioning a designated frequency spectrum within a service coverage area (.0.1, .0.2, or .0.3) into a first and at least second spectrum inclusive of the designated frequency spectrum, each with an associated power level, and offsetting the spectrums for each TDM frame under the control of an offset number unique to each TDM frame. Assignment of communication units to a spectrum and power level are based upon distance from the base site (as determined through signal strength measurements). The spectral content of spectrums in adjacent service coverage areas is adjusted to include non-coincidental frequencies.

Abstract: A radio communication system selects a serving transceiver for a remote unit by generating and using a center of mass location estimation. The radio communication system collects uplink and downlink signal characteristics, including impaired signals caused by co-channel interference, from a set of transceivers, including those adjacent to and non-adjacent to the candidate transceiver and remote unit, to aid in the estimation of the remote unit's location within the radio communication system. Using the uplink and downlink signal characteristics, the radio communication system determines weighted coordinates related to predetermined coordinates and the signal characteristics which are used to produce a first and second center of mass coordinate estimation. The radio communication system then selects the serving transceiver to be the transceiver whose predetermined coordinates are closest to the first and second center of mass coordinate estimation.

Abstract: A fixed base-site (115) periodically pages subscribers (120) in a paging area (100). To prolong the battery life of the subscribers (120), paging groups (520) are not sent to subscribers (120) as often when the paging load is small. Since the subscribers (120) support discontinuous receive, processing of the pages will not take place as frequently and thus a battery savings is realized. When the fixed base-site (115) receives more pages than can be supported without exceeding a predetermined delay, the fixed base-site (115) dynamically increases the frequency that paging groups (520) are transmitted to subscribers (120). When the paging load decreases, the fixed base-site (115) dynamically decreases the frequency that paging groups (520) are transmitted to subscribers (120) and again a savings in battery life is realized.

Abstract: A direct sequence code-division multiple access (DS CDMA) communication system schedules conveyance of blocks (400) of information such that the blocks arrive at a base-site (130) just-in-time for transmission during a discrete frame (301-305) of an air-interface. The DS CDMA communication system implements both circuit switching and packet switching approaches to provide trunking efficiencies while balancing between system loading constraints and time delay of blocks (400) during conveyance.

Abstract: A communication system dynamically assigns channels to a subscriber unit so as to, inter alia, mitigate the effects of co-channel interference in the system. The communication system has a plurality of base-stations receiving the transmission of a subscriber unit desiring service. Upon receipt of the subscriber unit's transmission, each base-station determines a signal quality value, which it then reports to a system controller. The system controller determines the best signal quality value reported and assigns a channel to the base-station which reported the best signal quality value. The chosen base-station transmits to the subscriber unit on an assigned channel to establish communication. The assigned channel transmitted by the chosen base-station need not be associated with the channel the subscriber transmits on. In fact, either channel may be any one of the channels allocated for use by the communication system.

Abstract: The power of a received signal is measured at a base station. This measured power is used to predict a future power level of the received signal and from that to determine the appropriate power adjustment command. The power adjustment command is then sent to the transceiver.

Abstract: In a wireless frequency and time division multiple access (FD/TDMA) communications system having time-slotted communications channels, there is provided a method of and apparatus for hopping wireless communications. It comprises sequencing slot assignments and sequencing frequency assignments, such that a multiplicity of frequencies are thereby usable at each site of a cellular FD/TDMA system without regard to local partitioning among surrounding uses thereof. The effect would be to probablistically reduce the interference, not only by the number of hopping frequencies, but by a factor of the number of time slots per frame.

Abstract: A method and apparatus is provided for transmitting spread spectrum signals. The transmitter receives data symbols. Subsequently, the transmitter splits each particular set of two received data symbols into a first and second array of data symbols according to either of two algorithms. The first algorithm including providing both data symbols of the particular set to the first and second array of data symbols and the second algorithm including providing one of the data symbols of the particular set to the first array of data symbols and the other of the data symbols of the particular set to the second array of data symbols. Subsequently, the transmitter determines particular channels to transmit the first and second array of data symbols by spreading the first and second array of data symbols with a predetermined length Walsh code.