Showing papers by "Qualcomm published in 2002"

Uniform illumination system

Abstract: A compact and efficient optical system featuring planar multi-layered LED light source arrays concentrating their polarized or unpolarized output within a limited angular range. The optical system manipulates light emitted by a planar light emitters such as electrically-interconnected LED chips. Each light emitting region in the array is surrounded by reflecting side-walls whose output is processed by elevated prismatic films, polarization converting films, or both. The optical interaction between light emitters, reflecting sidewalls and the elevated prismatic films create overlapping virtual images between emitting regions that contribute to the greater optical uniformity. Practical illumination applications of such uniform light source arrays include compact LCD of DMD video image projectors, as well as general lighting, automotive lighting, and LCD backlighting.

Method and apparatus for utilizing channel state information in a wireless communication system

Abstract: Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from each receive antenna comprising a combination of one or more signals transmitted from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver unit is processed based on the received CSI.

Method and apparatus for allocating downlink resources in a multiple-input multiple-output (MIMO) communication system

Abstract: Techniques to schedule downlink data transmission to a number of terminals in a wireless communication system. In one method, one or more sets of terminals are formed for possible data transmission, with each set including a unique combination of one or more terminals and corresponding to a hypothesis to be evaluated. One or more sub-hypotheses may further be formed for each hypothesis, with each sub-hypothesis corresponding to specific assignments of a number of transmit antennas to the one or more terminals in the hypothesis. The performance of each sub-hypothesis is then evaluated, and one of the evaluated sub-hypotheses is selected based on their performance. The terminal(s) in the selected sub-hypothesis are then scheduled for data transmission, and data is thereafter coded, modulated, and transmitted to each scheduled terminal from one or more transmit antennas assigned to the terminal.

Iterative detection and decoding for a mimo-ofdm system

Abstract: Techniques to iteratively detect and decode data transmitted in a wireless (e.g., MIMO-OFDM) communication system. The iterative detection and decoding is performed by iteratively passing soft (multi-bit) “a priori” information between a detector and a decoder. The detector receives modulation symbols, performs a detection function that is complementary to the symbol mapping performed at the transmitter, and provides soft-decision symbols for transmitted coded bits. “Extrinsic information” in the soft-decision symbols is then decoded by the decoder to provide its extrinsic information, which comprises the a priori information used by the detector in the detection process. The detection and decoding may be iterated a number of times. The soft-decision symbols and the a priori information may be represented using log-likelihood ratios (LLRs). Techniques are provided to reduce the computational complexity associated with deriving the LLRs, including interference nulling to isolate each transmitted signal and “dual-maxima” approximation.

Coding scheme for a wireless communication system

Abstract: Coding techniques for a (e.g., OFDM) communication system capable of transmitting data on a number of “transmission channels” at different information bit rates based on the channels' achieved SNR. A base code is used in combination with common or variable puncturing to achieve different coding rates required by the transmission channels. The data (i.e., information bits) for a data transmission is encoded with the base code, and the coded bits for each channel (or group of channels with the similar transmission capabilities) are punctured to achieve the required coding rate. The coded bits may be interleaved (e.g., to combat fading and remove correlation between coded bits in each modulation symbol) prior to puncturing. The unpunctured coded bits are grouped into non-binary symbols and mapped to modulation symbols (e.g., using Gray mapping). The modulation symbol may be “pre-conditioned” and prior to transmission.

Method and system for a data transmission in a communication system

Abstract: Methods and apparatus for a data transmission in a communication system are disclosed. Each of a subset of plural access terminals desiring to transmit user data in an interval transmits a request to transmit in the interval to an access network. The access network makes a decision to schedule at least one of the subset of the plural access terminals to transmit in the interval in accordance with the request. At least one access point of the access network transmits the decision to the plural access terminals.

Method and apparatus for security in a data processing system

Abstract: Method and apparatus for secure transmissions. Each user is provided a registration key. A long-time updated broadcast key is encrypted using the registration key and provided periodically to a user. A short-time updated key is encrypted using the broadcast key and provided periodically to a user. Broadcasts are then encrypted using the short-time key, wherein the user decrypts the broadcast message using the short-time key.

Method and apparatus for data packet transport in a wireless communication system using an internet protocol

Abstract: Method and apparatus for data packet transport in a wireless transmission system supporting broadcast transmissions. A multicast tree is built between nodes through neighboring routers. The multicast tree forms a tunnel through which the broadcast content is transmitted. The broadcast message is encapsulated in an Internet Protocol packet for transmission through the multicast tree. At least one multicast tree is formed between the Internet portion of the system and the wireless portion of the system, such as the Access Network. In one embodiment, an external multicast tree is formed between a content source and a packet data service node, and an internal multicast tree is formed between the packet data service node and a packet control function node.

Reverse link channel architecture for a wireless communication system

Abstract: A channel structure and mechanisms that support effective and efficient allocation and utilization of the reverse link resources. In one aspect, mechanisms are provided to quickly assign resources (e.g., a supplemental channel) as needed, and to quickly de-assign the resources when not needed or to maintain system stability. The reverse link resources may be quickly assigned and de-assigned via short messages (412, 418) exchanged on control channels on the forward and reverse links. In another aspect, mechanisms are provided to facilitate efficient and reliable data transmission. A reliable acknowledgment/negative acknowledgment scheme and an efficient retransmission scheme are provided. Mechanisms are also provided to control the transmit power and/or data rate of the remote terminals to achieve high performance and avoid instability.

Method and apparatus for controlling uplink transmissions of a wireless communication system

Abstract: Techniques to partition and allocate the available system resources among cells in a communication system, and to allocate the resources in each cell to terminals for data transmission on the uplink. In one aspect, adaptive reuse schemes are provided wherein the available system resources may be dynamically and/or adaptively partitioned and allocated to the cells based on a number of factors such as the observed interference levels, loading conditions, system requirements, and so on. A reuse plan is initially defined and may be redefined to reflect changes in the system. In another aspect, the system resources may be partitioned such that each cell is allocated a set of channels having different performance levels. In yet another aspect, terminals in each cell are scheduled for data transmission (e.g., based on their priority or load requirements) and assigned channels based on their tolerance to interference and the channels' performance.

Integrated chip package structure using organic substrate and method of manufacturing the same

Abstract: An integrated chip package structure and method of manufacturing the same is by adhering dies on an organic substrate and forming a thin-film circuit layer on top of the dies and the organic substrate. Wherein the thin-film circuit layer has an external circuitry, which is electrically connected to the metal pads of the dies, that extends to a region outside the active surface of the dies for fanning out the metal pads of the dies. Furthermore, a plurality of active devices and an internal circuitry is located on the active surface of the dies. Signal for the active devices are transmitted through the internal circuitry to the external circuitry and from the external circuitry through the internal circuitry back to other active devices. Moreover, the chip package structure allows multiple dies with different functions to be packaged into an integrated package and electrically connecting the dies by the external circuitry.

Systems and methods for delivering information within a group communications system

Abstract: System and methods for delivering information include a communications network defined by at least a wireless telephone network (22) coupled to a computer network (24), where the communications network is associated with a plurality of communication devices (14, 16, 18, 20) that define a group communications net. A communications manager (32) is operable to provide a group communication session by receiving a data packet from one member of the group communications net and transmitting the data packet through the computer network to at least one of the other members of the group communications net. A message module (28) having a plurality of informational messages is associated with the communications manager, and a delivery module (30) is coupled to each of the message module, the communications manager, and the communications network. The delivery module is operable to monitor the group communication session and to deliver one of the plurality of informational massages to the group communications net. Further, methods of billing a user for participation in the group communications session include discounting an amount due based on receipt of informational messages.

Method and apparatus for enabling group communication services in an existing communication system

Abstract: An apparatus to form a group of communication devices over a distributed network is claimed. A first node establishes a first channel with a first communication device. At least one second node establishes at least one second channel with at least one second communication device. A controller electrically connected to the first node and the at least one second node comprises a database module. The database module comprises identification information of each of the communication devices of the group. The controller is dynamically configurable such that any single communication device of the group is capable of sending packet data through its respective channel to the other communication devices of the group.

Method and apparatus for controlling transmit power of multiple channels in a CDMA communication system

Abstract: Techniques to support independent power control of multiple channels in CDMA systems (e.g., a W-CDMA system) that define a single power control feedback steam on the uplink, which is to be used for downlink power control. In one aspect, the single feedback stream is 'time shared' among multiple channels requiring individual power control. Various time-sharing schemes may be used to implement multiple (substantially parallel) feedback substreams based on the single feedback stream, and different combination of feedback rates may also be achieved for the substreams. Each feedback substream may be assigned to, and used for power control of, a respective channel. In another aspect, multiple feedback substreams are implemented based on multiple fields in newly defined slot formats.

Idle mode handling in a hybrid GSM/CDMA network

Abstract: In a mobile wireless telecommunications system, which includes base stations (30) of a first type operating over a first air interface, and base stations (32) of a second type operating over a second air interface, a method for reselection by a mobile station (40) camped on a cell associated with a first base station (30), which is of the first type, of a second base station (32), which is of the second type. The method includes receiving signals over the second air interface from the second base station (32) and evaluating a characteristic of the signals. Responsive to the characteristic, the second base station (32) is selected in place of the first base station (30), and the mobile station (40) camps on a cell associated with the second base station (32).

Method for open loop tracking GPS signals

Abstract: Method and apparatuses for receiving and tracking satellite signals in a highly sensitive and accurate receiver. In one aspect of the invention an exemplary method includes generating a set of at least three indicators based on processing a portion of a satellite positioning system signal received by a receiver and computing a measurement of a parameter from an interpolation of the set of indicators. Each of the indicators corresponds to a different predetermined hypothesized value of the parameter and is indicative of a probability, or likelihood, that the parameter of the signal is equal to that corresponding value.

Feedback gain in multiple antenna systems

Abstract: Multiple antenna transmission and reception have been shown to significantly increase the achievable data rates of wireless systems. However, most of the existing analysis assumes perfect or no channel information at the receiver and transmitter. The performance gap between these extreme channel assumptions is large and most practical systems lie in between. Therefore, it is important to analyze multiple antenna systems in the presence of partial channel information. We upper bound the outage probability performance of multiple antenna systems with preamble-based channel estimation and quantized feedback. We design causal feedback and power control schemes to minimize this upper bound on outage probability. We consider the following practical issues in our analysis and design: (1) the channel information is imperfect both at the receiver and at the transmitter and (2) part of the total available resources for the system need to be used for estimation and feedback. Our results demonstrate that for block fading channels, sending a periodic preamble and causally receiving channel state information via a feedback channel can lead to substantial gains in the outage performance over any nonfeedback scheme. Most of the gains achieved by perfect feedback can be achieved by very few bits of feedback. Furthermore, it is demonstrated that these outage probability gains can be translated into improvements in frame error rate performance of systems using space-time codes. Thus, implementing a power control, even at the cost of reduced spectral resources for the forward channel is beneficial for block fading channels.

System for automatically configuring features on a mobile telephone based on geographic location

Abstract: A system for automatically reconfiguring a mobile telephone based on geographic location. In the illustrative embodiment, the invention includes a storing unit (40) and an execution unit (70). The storing unit (40) allows the user to save a particular location and the desired configurations corresponding to that location. The execution unit (70) monitors the position of the telephone and, upon entering a saved location, executes the configurations corresponding to that location. The execution unit (70) also returns the configurations to their previous settings after the telephone has exited from the saved location.

Method and apparatus for time-aligning transmissions from multiple base stations in a CDMA communication system

Abstract: Schemes to time-align transmissions from multiple base stations to a terminal. To achieve time-alignment, differences between the arrival times of transmissions from the base stations, as observed at the terminal, are determined and provided to the system and used to adjust the timing at the base stations such that terminal-specific radio frames arrive at the terminal within a particular time window. In one scheme, a time difference between two base stations is partitioned into a frame-level time difference and a chip-level time difference. Whenever requested to perform and report time difference measurements, the terminal measures the chip-level timing for each candidate base station relative to a reference base station. Additionally, the terminal also measures the frame-level timing and includes this information in the time difference measurement only if required. Otherwise, the terminal sets the frame-level part to a predetermined value (e.g., zero).

Multi-mode satellite and terrestrial communication device

Abstract: The present invention provides a multiple band mobile radio (also referred to as a Wireless Communication Device (WCD)) (102) capable of communicating with both a satellite communication system (108, 114) and a terrestrial communication system (120, 122). The satellite communication system can be, for example, a Low Earth Orbit (LEO) satellite system. The terrestrial communication system can be a Personal Communication System (PCS), or a cellular system, including either an analog or a digitally based cellular syst∩m. The cellular analog system can be AMPS. The digitally based cellular system can be a CDMA or a TDMA based communication system. The WCD (102,300,400,500,600,700, 800,900, 1000, 1100) can concurrently receive signals from the terrestrial communication system and the satellite communication system.

Method and apparatus for transmit power modulation in a wireless communication system

Abstract: An apparatus according to one embodiment of the invention includes a transmitter. The transmitter comprises a first gain element configured and arranged to modulate a radio-frequency signal according to a first gain factor to produce a first output signal; and a second gain element configured and arranged to modulate the radio-frequency signal according to a second gain factor to produce a second output signal, wherein a magnitude of the first gain factor varies over time, and wherein a magnitude of the second gain factor varies over time with respect ot the magnitude of the first gain factor. Each of the modulated signals is coupled to a respective antenna. The combined radiation pattern of the antennas varies in an angular direction over time. In a system according to one embodiment of the invention, a base station including such an apparatus receives channel quality indications from mobile units and schedules data transmissions to the mobile units accordingly.

Power control for a channel with multiple formats in a communication system

Abstract: Techniques to more efficiently control the transmit power for a data transmission that uses a number of formats (e.g., rates, transport formats). Different formats for a given data channel (e.g., transport channel) may require different target SNIRs to achieved a particular BLER. In one aspect, individual target BLER may be specified for each format of each data channel. In another aspect, various power control schemes are provided to achieve different target SNIRs for different formats. In a first power control scheme, multiple individual outer loops are maintained for multiple formats. For each format, its associated outer loop attempts to set the target SNIR such that the target BLER specified for that format is achieved. In a second power control scheme, multiple individual outer loops are maintained and the base station further applies different adjustments to the transmit power levels for different formats.

Method and apparatus providing improved position estimate based on an initial coarse position estimate

Abstract: Techniques for determining the location of a device based on an initial coarse position estimate for the device, which is derived based on initial (less accurate) estimates of the position of a plurality of transmitters. In one method, the coarse position estimate for the device and revised (more accurate) position estimates for the transmitters are received. A revised position estimate for the device is initialized (e.g., to the coarse position estimate). An update vector is next computed based on the initial and revised position estimates for the device and the initial and revised position estimates for the transmitters. The revised position estimate for the device is then updated based on the update vector. The computation for the update vector and the updating of the revised position estimate for the device can be repeated a number of times to achieve a more and more accurate estimate.

A noise optimization technique for integrated low-noise amplifiers

Abstract: Based on measured four-noise parameters and two-port noise theory, considerations for noise optimization of integrated low-noise amplifier (LNA) designs are presented. If arbitrary values of source impedance are allowed, optimal noise performance of the LNA is obtained by adjusting the source degeneration inductance. Even for a fixed source impedance, the integrated LNA can achieve near NF/sub min/ by choosing an appropriate device geometry along with an optimal bias condition. An 800 MHz LNA has been implemented in a standard 0.24 /spl mu/m CMOS technology. The amplifier possesses a 0.9 dB noise figure with a 7.1 dBm third-order input intercept point, while drawing 7.5 mW from a 2.0 V power supply, demonstrating that the proposed methodology can accurately predict noise performance of integrated LNA designs.

Beacon for locating and tracking wireless terminals

Abstract: A method and apparatus to facilitate the locating and tracking of a wireless terminal, which may be advantageously used for E-911 service. The terminal may be directed to transmit a beacon for certain events, such as in connection with a 911 call. The beacon has a specific format known by the wireless network, and may be periodically or continuously transmitted. The beacon may be transmitted using various schemes. In a first scheme, the terminal transmits the beacon only when directed to do so by a designated network entity (e.g., the PSAP). In a second scheme, the terminal transmits the beacon in conjunction with the 911 call, and is thereafter directed to terminate the beacon transmission by the designated network entity. The beacon allows the terminal to be accurately located even if it has moved or is physically located in an enclosed or “not-so-obvious” location.

Method and system for a handoff in a broadcast communication system

Abstract: A method and system for a handoff in a broadcast communication system is disclosed. A subscriber assisted handoff is impractical in a broadcast communication system due to e.g., a high signaling load, a difficulty to synchronize the broadcast transmission. On the other hand, the small number of broadcast channels enables the subscriber station to perform the handoff autonomously. To streamline the autonomous handoff decision process, several distinct sets of pilot identifiers and rules for transitioning among the sets are defined. To fully integrate broadcast services with the services provided by the cellular telephone systems in a subscriber environment, a methods for various handoff scenarios are analyzed.

Resource allocation in a wireless communication system

Abstract: Method and apparatus for scheduling transmissions in a wireless communication system using historical information and usage patterns of remote users in the system. Usage patterns for users within a system are stored and analyzed to optimize transmissions and resources in the system. In one embodiment, the user patterns are used to predict travel routes and transmissions scheduled accordingly. In another embodiment, the system is an ad-hoc system or a hybrid system, wherein the usage patterns are used to determine the source-to-destination paths.

Rate selection for an ofdm system

Abstract: Techniques to determine the rate for a data transmission in an OFDM system. The maximum data rate that may be reliably transmitted over a given multipath (non-flat) channel by the OFDM system is determined based on a metric for an equivalent (flat) channel. For the given multipath channel and a particular rate (which may be indicative of a particular data rate, modulation scheme, and coding rate), the metric is initially derived from an equivalent data rate and the particular modulation scheme. A threshold SNR needed to reliably transmit the particular data rate using the particular modulation scheme and coding rate is then determined. The particular rate is deemed as being supported by the multipath channel if the metric is greater than or equal to the threshold SNR. Incremental transmission is used to account for errors in the determined data rate.

Reverse link power controlled repeater

Abstract: The invention provides a mechanism for automatically setting reverse link gain or power for a repeater (120) used in a communication system (100) through the use of the reverse link power control of a built-in wireless communications device. By embedding a wireless communication device (430, 630, 700) inside the repeater and injecting reverse link signals of the embedded device into the reverse link of the repeater (124A, 124B), the gain of the repeater is maintained relatively constant. The embedded WCD can also be activated on a periodic basis to make calls and utilize reverse link power-control to calibrate or re-calibrate the gain of the repeater, making it a power-controlled repeater.

Method and apparatus for testing traffic and auxiliary channels in a wireless data communication system

Abstract: Techniques to test performance of terminals and access points in CDMA data (e.g., cdma2000) systems. A framework of protocols and messages is provided to support systematic performance testing of terminals and to ensure interface compatibility. The framework comprises a Forward Test Application Protocol (FTAP) for testing forward channels and a Reverse Test Application Protocol (RTAP) for testing reverse channels. Techniques are also provided to (1) test different types of channels (e.g., traffic channels as well as auxiliary channels), (2) test bursty data transmissions, (3) support “persistence” testing (i.e., continued testing over connection and disconnection), (4) force the settings of certain auxiliary channels (e.g., so that the error rate of the channels may be determined), and (5) collect, log, and report various statistics that may be used to derive performance metrics such as throughput and packet error rate.