Abstract: A method and system for controlling down link transmit power during a soft hand-off in a spread-spectrum wireless system supports independent power control of multiple forward channels to reduce fading. For a soft hand-off, a mobile switching center determines if a forward control channel is transmitted from different sectors of base stations than a forward data channel is. The base stations preferably adjust transmit powers of the forward channels grouped into different physical channels by receiving power control data over the allocated reverse power control channels to compensate for fading of the forward channels during a soft hand-off.

Abstract: A method that initiates call blocking responsive to a call-quality measurement of the forward link. The call-quality measurement is a measurement of how well a mobile terminal is able to receive the forward link. One call-quality measurement is a pilot fraction of the forward link, which is a ratio of the pilot's power level to the power level of a set of forward-link signals of a base station. Call blocking is initiated when an average pilot fraction is below a pilot-fraction blocking threshold. The pilot's power level is obtained for a time period, and the signal set's power level is obtained for the same time period. The pilot fraction is determined for the time period, and then used to determine the average pilot fraction for the time period. The average pilot fraction for the current time period is based on a pilot fraction for the current time period, and an average pilot fraction for a previous time period.

Abstract: In a system of communication, a sending node sends a message to a receiving node, which NAKs unsuccessful transmissions. The sending node screens the NAKs to determine if they were sent before the receiver could receive previous transmissions of the same data NAKed. One screening technique is based on an estimated round trip time of a message. Another alternate technique looks a flag in the NAK that synchronizes the sender and the receiver.

Abstract: A method and apparatus that can cancel the non-orthogonal code channel signals to minimize the interference in the detection for desired signals, first uses the channel estimate via pilot signal to reconstruct the signal at non-orthogonal code channel (e.g., SCH), then removes (subtracts) the reconstructed signal from the received signal before the decoding and detection of other code channels. The cancellation of interference from non-orthogonal signal can significantly improve the performance of the detection of the desired signal (user data or broadcast data) and thus more system capacity can be obtained.

Abstract: The present invention is a more accurate system for estimating the location of a mobile-telephone without significantly increasing the interference level for other mobile-telephones in the same or neighboring cells. In one embodiment, the present invention uses a plurality of location terminals deployed throughout a cell to increase the chances of detecting line-of-sight signals and the signal-to-noise ratio at the location terminals. In this embodiment, a wireless communication network transmits receive information to the plurality of location terminals instructing each of the location terminals to receive a signal from a particular mobile-telephone. Specifically, the location terminal is instructed to monitor a specific communication channel during a specific time interval.

Abstract: An apparatus for performance improvement of a digital wireless receiver, having a plurality of signals, has a processing circuit and a weight generation circuit. The processing circuit provides a processed signal, wherein a plurality of weights is applied to a plurality of signals producing a plurality of weighted signals and the plurality of weighted signals are combined to provide the processed signal. In the weight generation circuit the plurality of weights are generated as a function of a conjugate of channel estimate of a corresponding signal of the plurality of signals and a variance of the corresponding signal. A method implementing the present invention is also described.

Abstract: The wireless CDMA system includes a base station which generates a configuration channel as one of the forward control channels. The message slots in the configuration channel only include overhead messages. The base station also generates at least one other forward control channel, but these other forward control channels do not need to include overhead messages in any of their message slots. The mobiles in the system determine the location of the configuration channel from information in a sync channel generated by the base station. By camping onto the configuration channel, a mobile can quickly obtain the overhead parameters in the overhead messages. Because obtaining overhead parameters and keeping an updated version of the overhead parameters is an important factor in overall performance, the significant decrease in overhead message access time provided by the provision of the configuration channel greatly improves performance.

Abstract: A method and apparatus to estimate the channel fade (both the amplitude gain/loss and the phase rotation) to assist the receiver to detect and recover the transmitted signal employs a continuous pilot signal such as the pilot code channel or pilot symbols. The channel estimator uses the same scrambling pattern of pilot channel and coherently integrates the continuous pilot signal to yield a channel estimate. The present invention employs adaptive integration duration to yield a channel estimate. The integration duration of the pilot signal for channel estimation is adaptive and proportional to the Doppler period. The Doppler period is proportional to the inverse of Doppler frequency and is an indicator of how fast the channel changes.

Abstract: A method for reducing multiple dominant pilots in a CDMA transmission system comprises linking a transceiver element with a nearby base station for transporting signals between the transceiver element and the nearby base station. Transmitting from the transceiver element forward link signals of a nearby sector associated with the nearby base station. An apparatus is also described.

Abstract: Inter-frequency handoffs in a CDMA or other wireless communication system are controlled using a noise-limited coverage trigger metric which is able to distinguish between same-frequency cell boundaries and other-frequency cell boundaries in the system. The trigger metric may be generated as a function of an average signal-to-noise measure for pilot signals received at a mobile station of the system and a linear sum of the signal-to-noise measures. The signal-to-noise measures may be generated in the mobile station and included in messages transmitted from the mobile station to one or more base stations of the system. The trigger metric is used to control a handoff from a current frequency to a new frequency in an ongoing call. The trigger metric may alternatively be based on a measure of mobile receive power alone.

Abstract: An apparatus for reducing power amplifier headroom in a wireless transmission system comprises an orthogonal modulation circuit and a phase rotation circuit coupled to the orthogonal modulation circuit. The orthogonal modulation circuit utilizes a Walsh code for modulating an in-phase signal and a quadrature signal. The orthogonal modulation circuit has an in-phase output and a quadrature output. The phase rotation circuit rotates phase of the in-phase signal and the quadrature signal, producing a phase rotated in-phase signal and a phase rotated quadrature signal. Multiple Walsh code defined channels are associated with a particular wireless user.

Abstract: A mobile communications system employs extended channel assignment messaging during the call setup portion of a mobile call. As part of the call setup process, a mobile station sends an access request message to a primary base station that includes a list of alternate base stations. As call setup continues, the mobile station employs diversity reception in monitoring the paging channel of three base stations, each selected as a function of the strength of the signal-to-noise ratios of their respective pilot tones.

Abstract: A method for extending a cell radius or access range of a base station without incurring ASIC correlator re-design. This is accomplished using a modified timing protocol that will cause signals transmitted by mobile-telephones positioned beyond the limitations of the ASIC correlator bit limitation to be received within a search window so the signals may be detected and demodulated. In one embodiment, the modified timing protocol incorporates a timing advance technique in which the base station transmits its signals at an advanced time before frame boundaries such that signals transmitted by out-of-range mobile-telephones can be received within a search window beginning at a frame boundary and spanning a time interval corresponding to the ASIC correlator bit limitation. In another embodiment, the modified timing protocol incorporates a shifted search window that begins at an advanced time after a frame boundary and spans a time interval corresponding to the ASIC correlator bit limitation.

Abstract: A power control method of the invention may be applied to downlink power control, uplink power control, or both to support different quality of service levels for multiple channels per a mobile station. The power control method transmits control data between a base station and a multi-channel mobile station on a single communications channel or sub-channel to minimize or reduce overhead traffic from the control data.

Abstract: Inter-frequency handoffs in a CDMA or other wireless communication system are controlled using a noise-limited coverage trigger metric which is able to distinguish between same-frequency cell boundaries and other-frequency cell boundaries in the system. The trigger metric may be generated as a function of an average signal-to-noise measure for pilot signals received at a mobile station of the system and a linear sum of the signal-to-noise measures. The signal-to-noise measures may be generated in the mobile station and included in messages transmitted from the mobile station to one or more base stations of the system. The trigger metric is used to control a handoff from a current frequency to a new frequency in an ongoing call. The trigger metric may alternatively be based on a measure of mobile receive power alone.

Abstract: The present invention is a extended range concentric cell base station and a method for extending a cell size or access range without incurring ASIC correlator re-design. This is accomplished with a concentric cell base station design that incorporates multiple timing protocols. The concentric base station has associated a micro cell and a macro cell, wherein the micro and macro cells use a different timing protocol that will cause signals transmitted by mobiles within their respective cells to be received within the confines of search windows associated with the timing protocols.

Abstract: An apparatus and method which, in a wireless communication system, improve the quality of inter-frequency hand-offs from an existing call connection frequency to a new frequency by minimizing oscillating inter-frequency hand-offs between the existing call connection frequency and the new frequency, and by minimizing redundant and unnecessary tuning and searching at the new frequency. The present invention accomplishes this improvement by adding specific threshold comparison values (or triggers) within existing messages and through more robust data reporting, from the mobile unit to the base station, when tuning and searching is performed. Particularly, two comparative triggers provided by the present invention avoid unnecessary tuning and searching in the new frequency, thus reducing voice degradation and the risk of dropped calls while pilot searching in the current frequency.

Abstract: Methods and apparatus for estimating mobile station location in a wireless communication system. At initiation of a call or a page response, a mobile station of the system sends an access request signal to a primary base station. The primary base station responds with an access acknowledgment which may be intentionally delayed such that the mobile station increases its transmit power level. The primary base station then transmits a channel assignment message to the mobile station. The mobile station responds by transmitting a location signal in the form of a known user-specific traffic preamble at the higher transmit power level. The primary base station intentionally delays sending an acknowledgment of the preamble, such that the mobile station transmits the preamble for a longer period of time than it would otherwise.

Abstract: The present invention increases the success rate of soft handoffs by enhancing the ability of a mobile-telephone to receive a handoff direction message that identifies the traffic channel being assigned to enable a candidate base station to communicate with the mobile-telephone. Specifically, the aforementioned ability of the mobile-telephone is enhanced by using the candidate base station to transmit the handoff direction message on a communication channel belonging to the candidate base station and being listened to by the mobile-telephone. In situations where signals transmitted from active set base stations have a low signal-to-noise ratio at the mobile-telephone, signals transmitted from the candidate base station may have a higher signal-to-noise ratio at the mobile-telephone.

Abstract: A method for increasing the success rate for soft handoffs, particularly under rapidly fluctuating fading conditions, using traffic channels of active set base stations. In one embodiment of the present invention, increased success rate for soft handoffs is achieved using a candidate base station, in addition to the active set base stations, to transmit a handoff command message to the mobile-telephone. Specifically, the handoff command message is transmitted by the active set base stations over the traffic channels assigned to mobile-telephone for communicating with the active set base stations, and by the candidate base station over the traffic channel assigned to the mobile-telephone for communicating with a primary base station. Additionally, a pilot signal may be transmitted by the candidate base station to enable the mobile-telephone to coherently demodulate the handoff direction message transmitted by the candidate base station.