Abstract: The present invention is a novel method and apparatus for initiating a reverse link intergenerational handoff in a CDMA communication system. The reverse link intergenerational handoff initialization method and apparatus of the present invention measures and compares parameters between a serving base station of one generation and a target base station of another generation to determine the best possible handoff initiation time instant for performing a reverse link intergenerational hard handoff. The present invention can utilize one of several embodiments to determine the best possible handoff initiation time instant. A pilot signal strength embodiment of the present invention determines a handoff initiation time instant based upon the total pilot signal strength of both a serving and target base station.

Abstract: A novel method and apparatus for performing cell selection handoffs in a wireless communication system is disclosed. The CSHO method and apparatus of the present invention determines which transmitters to temporarily disable or “gate off” during soft handoff procedures. The method and apparatus of the present invention monitors the channel conditions for all base stations in an active set of a selected mobile station and determines the relative strengths of base stations based on the monitored channel conditions. The method and apparatus of the present invention reduces interference to receivers in a wireless communication system. Specifically, the present invention temporarily disables, or “gates off” selected transmitters (e.g., base stations) during soft handoff procedures and thereby reduces interference to receivers that are not associated with the selected transmitters. Reducing this interference increases the overall voice and data capacity in a wireless communication system.

Abstract: A wireless communication mobile station (MS or UE) evaluates and categorizes an expected effectiveness of base stations (BSs or Node-Bs) in its Active Set for receiving uplink data, and instructs at least the less effective BSs to suppress some or all acknowledgment signals with respect to particular uplink data packets from the UE. A Target Select message is described for notifying the BSs of their Acknowledgment Target Select category, and a Target Select channel is described for conveying the Target Select message to all Active Set BSs so that they can suppress acknowledgment signaling with respect to corresponding data packets as appropriate for their Acknowledgment Target Select category.

Abstract: A common signaling channel (CSC) conveys signaling information units (SIUs) from a base station (BS) to each of a multiplicity (e.g., 1200) of different mobile stations (MSs). Implicit correspondence between particular CSC and data frames is facilitated by basing CSC frame duration on the data frame period. CSC frames are time multiplexed into K subframes, which are code division multiplexed (CDM) into J CDM branches to define J*K SIUs. CDM symbols (or sequences) representing each SIU may be diversely transmitted in different time slots, and/or using different OVSF codes or subchannels. Unique gain may be provided for each SIU. Subframe duration may ensure CDM code orthogonality despite fading. CDM symbol length may be an integer power of two, or have other values, such as 2N*20 (e.g., 80). SIUs are typically relevant to BS-MS data packets, for example ACKs supporting H-ARQ for reverse link transmissions.

Abstract: A method of extending, for enabled stations, the number of information states conveyed by a signal employed by legacy (non-enabled) stations. The additional information states may convey a Broadcast/Multicast Service (BCMCS) Indication by means of tristate modulation, including binary phase shift keying plus zero amplitude. A signal, such as a quick paging (QP) message, is selected because legacy receivers combine subunits of the message before the data content is determined. Complementary modulation is applied to the subunits, such that legacy combining renders the message information indistinguishable from harmless messages, yet distinguishable as a distinct additional information state in a legacy receiver. For example, a legacy receiver cannot distinguish a new QP message from a “zero” signal, due to application of inverse BPSK to the subunits. An enabled station may thus detect new information, such as a BCMCS Indicator, in a manner that is compatible with legacy stations.

Abstract: A novel method and apparatus for controlling forward link power when an intergenerational soft handoff is performed in CDMA communication system is disclosed. The forward link power control method and apparatus of the present invention determines acceptable forward link power levels for a selected target base station during intergenerational soft handoff (ISHO) procedures. The method and apparatus of the present invention controls the forward link power for the selected target base station during an ISHO procedure. Open loop and slow forward power control embodiments of the present invention rely upon an observation that information regarding a mobile station serving forward traffic channel can be communicated to the selected target base station using an MSC. In another embodiment, a statistical value can be used to determine a forward link transmit power of a selected target base station.

Abstract: A method and apparatus to provide a common signaling channel (CSC) for concurrently signaling a multiplicity of different mobile stations (MSs) to facilitate data communications with a base station (BS). Superframes of the CSC have a length related to the period of corresponding data channel frames, so that disposing signaling information units (SIUs) in a superframe may imply relevance to particular data frames. Each CSC superframe is multiplexed by time (TDM) into subframes, which are further multiplexed by code (CDM). Symbols representing the same SIU may be disposed in plural subframes to provide time diversity. The number of subframes per superframe may be selected to reduce impairment of CDM code orthogonality, and/or to permit using an integer power of two number of symbols within each subframe. A CSC may, for example, provide ACK information for data from numerous MSs, supporting H-ARQ for reverse link transmissions.

Abstract: A method and apparatus managing a list of base stations (“BSs”) for which a mobile station (“MS”) can establish an optimal communications channel are disclosed. In accordance with the teachings disclosed herein, a MS acquires suitable parameter information (“information”) and bases a subsequent switching decision based upon such information. Suitable parameters comprise cell loading and/or service priority, and MS needs. Such information comprises, for example, a number of BS users, switching latency associated with a particular BS, applications available by a BS, available code space, and a number of MSs for which a particular BS can provide resources. A MS decision to switch from a first BS to a second BS is predicated upon the acquired information.

Abstract: Extending acknowledgement messages from two states to at least three states is described, whereby such messages constitute a packet quality indication (PQI) reflecting quality or usability of the received signal. In an HARQ system, a transmitting station can flexibly select a better alternative for the next information to transmit on the basis of such PQI. One aspect includes determining how best to correct an unsuccessful packet transmission based on quality information about the specific packet. Implementing apparatus and procedures are described.

Abstract: The present invention a system and method are provided for performing an inter-frequency search with reduced loss of link frames in a CDMA system. The CDMA system includes a base station (20) and a mobile station (50). The mobile station (50) has a searcher (164), which searches for pilot channels. The signal strengths of these pilot channels are then reported to the base station (20). This searching results in erased portions of a data frame (238). After the signal strengths are reported to the base station (20), the mobile station (50) informs the base station (20) of the parameters related to the search. These parameters may include the frame of the search, the start position of the search, and the length of the search. The mobile station (50) and the base station (20) then replaces the erased portions of the frame with corrective data such as soft zeros.

Abstract: In a method and apparatus suitable to convey timely information for facilitating accurate reception of transmitted data, a pilot signal is modulated to convey information. The information may facilitate efficient interpretation of an associated traffic signal. Modulation of a pilot signal frame may be limited to ensure early detection, and/or to minimize impairment of pilot functionality. In one embodiment, a Secondary Pilot Channel (SPICH) is transmitted at one of several selectable power levels to boost effectiveness of a phase reference, and is modulated to indicate the selected level. Such timely information enables prompt optimal combining of the SPICH with a primary Pilot Channel (PICH), and/or permits processing efficiencies for an associated traffic channel. Pilot signal frames may be transmitted at a predetermined level during a detection preamble portion of a frame to ensure accurate and early detection, and at a more optimal level thereafter.

Abstract: A method and apparatus for communicating data signals using a spread spectrum cellular network, the cellular network including a plurality of base stations coupled to the cellular network the mobile unit assigned to one of the plurality of base stations. The method and apparatus receives a signal of another of the plurality of base stations (target base station) and determines the interference density to the target base station from the received signal.

Abstract: A method and apparatus to provide a common signaling channel (CSC) for concurrently signaling a multiplicity of different mobile stations (MSs) to facilitate data communications with a base station (BS). Superframes of the CSC have a length related to the period of corresponding data channel frames, so that disposing signaling information units (SIUs) in a superframe may imply relevance to particular data frames. Each CSC superframe is multiplexed by time (TDM) into subframes, which are further multiplexed by code (CDM). Symbols representing the same SIU may be disposed in plural subframes to provide time diversity. The number of subframes per superframe may be selected to reduce impairment of CDM code orthogonality, and/or to permit using an integer power of two number of symbols within each subframe. A CSC may, for example, provide ACK information for data from numerous MSs, supporting H-ARQ for reverse link transmissions.

Abstract: In a CDMA cellular radiotelephone system, a soft handoff (SHO) is performed when a mobile station communicates with a new inter-generation base station, without interrupting communications with the old base station. Currently, a SHO can only be used between CDMA channels having identical frequency assignments and within the same system generation (i.e., 2G⇄2G, or 3G⇄3G, where 2G is a second generation system, and 3G is a third generation system). The proposed IS-2000 standard for a 2G⇄3G handoff is a hard handoff or “Break-Before-Make” procedure, which greatly reduces the quality of service (QOS). The present invention allows for SHO between second and third generation CDMA systems (2G⇄3G and 3G⇄2G), by modifying the proposed messaging structure. This provides a smooth service transition when a mobile station travels from one service area (i.e., 2G), to another service area (i.e., 3G), using the SHO or “Make-Before-Break” approach.

Abstract: A method and apparatus for enabling more efficient use of plural packet data control channels (PDCCHs) that are associated with a common block of one or more packet data channels in a cellular communication system capable of high-speed data communications. Mobile stations (MSs) within a coverage area of a base station (BS) are categorized in accordance with an expected ability to receive signal transmissions, by determining position, transmission path length, reported channel quality, required reverse transmit power, or otherwise. The plural PDCCHs are preferentially associated with different categories of MSs, and are transmitted at different levels of robustness. The most robust PDCCH reaches all served MSs, and another PDCCH is transmitted at a lower robustness for more efficient utilization. Power may be reduced, and/or data density increased, on a less robust PDCCH.

Abstract: A method and apparatus for reducing power dissipation in mobile stations that are configured to provide concurrent voice and high-speed packet data communication capability in a cellular telecommunications system. A state is defined during which data directed to a mobile station (MS) is not received bu the MS. Such a reduced receive processing state may be co-extensive with a Control Hold state. A need to process received signals, particularly on high bit-rate data channels, may be reduced by permitting receive processing to be suspended for signals that are not directed to a particular mobile station. A notification mechanism is presented by which a serving base station directs a mobile station to return from reduced to full receive processing in advance of transmitting data on a packet data channel. The notification may take several forms, such as a message presenting the MS MAC address and one or more bits of predetermined data content.

Abstract: A method of time division multiplexing for a forward data packet channel includes encoding parallel data sub-packets into parallel streams of turbo codes; interleaving each of the parallel streams of turbo codes to generate parallel streams of quasi-complementary turbo codes; modulating the parallel streams of quasi-complementary turbo codes to generate parallel streams of modulated data symbols; and multiplexing the parallel streams of modulated data symbols by one of multiplexing and non-complete puncturing to generate a single stream of modulation symbols.

Abstract: A method for power control during soft handoffs is disclosed for a multi-user CDMA system having mixed system types, such as IS-95A/B and IS-2000. The procedure includes modifying the Forward Power Control (FPC) and Reverse Power Control (RPC) processing, in order to maintain proper power control between a mobile station and two different base stations during a soft handoff. The mobile station maintains the forward and reverse power control while still receiving forward links from different generation base stations, and while maintaining the reverse link to only one of these base stations. Prior to the soft handoff the second base station suspends FPC and RPC processing. Once the soft handoff is complete, the second base station resumes FPC and RPC processing. Furthermore, the mobile station's initial transmit power level is set to be within a predetermined limit.

Abstract: A method of synchronizing measurement of a mobile station location with communications service includes performing communications service between the mobile station and a base station, transmitting a synchronization message from the mobile station to the base station to indicate that the mobile station will be unavailable for communications service during a selected time interval, measuring the mobile station location from the mobile station during the selected time interval, and resuming communications service between the mobile station and the base station.

Abstract: In a CDMA cellular radiotelephone system, a soft handoff (SHO) is performed when a mobile station communicates with a new inter-generation base station, without interrupting communications with the old base station. Currently, a SHO can only be used between CDMA channels having identical frequency assignments and within the same system generation (i.e., 2G2G, or 3G3G, where 2G is a second generation system, and 3G is a third generation system). The proposed IS-2000 standard for a 2G3G handoff is a hard handoff or “Break-Before-Make” procedure, which greatly reduces the quality of service (QOS). The present invention allows for SHO between second and third generation CDMA systems (2G3G and 3G2G), by modifying the proposed messaging structure. This provides a smooth service transition when a mobile station travels from one service area (i.e., 2G), to another service area (i.e., 3G), using the SHO or “Make-Before-Break” approach.