Abstract:
A subscriber access unit includes a transceiver for providing wireless communication of digital signals. The digital signals are communicated to a base station using at least one radio frequency (RF) channel via Code Division Multiple Access (CDMA) modulated radio signals defined by orthogonal codes. Orthogonal subchannels are made available by the base station within each CDMA RF channel. A bandwidth manager is connected to the transceiver, and when the transceiver is actively sending data, at least one orthogonal subchannel is allocated by the base station on an as-needed basis. The number of orthogonal subchannels being allocated changes during a given session. The transceiver, when powered on but not actively sending data, provides an idling mode connection on a reverse link. The idling mode connection is based on an orthogonal subchannel shared with at least one other subscriber access unit, but utilizes different time slots of the shared orthogonal subchannel.
Abstract:
A communications system and method for a wireless mobile device is provided. The method includes performing sleep mode operations in a device and performing wake-up operations with one or more base stations in view of the sleep mode operations in the device. The method also includes demodulating a communications channel for the device during sleep mode operations in the device and prior to synchronizing with the base stations.
Abstract:
Disclosed is a method and system for estimating an adaptive joint channel in a CDMA system based on TDD. The method includes the steps of a) receiving activity information of a mobile terminal; b) parsing the activity information, and transmitting a midamble sequence to the mobile terminal when a result of the parsing shows that the mobile terminal is in an ON state; c) conducting adaptive joint channel estimation by using the midamble sequence in the mobile terminal; and d) conducting adaptive joint detection by using a channel impulse response of the mobile terminal, obtained as a result of conducting the adaptive joint channel estimation. The method and system decreases the complexity in channel estimation and additionally increases the accuracy of channel estimation by reducing transmission power consumption and eliminating unnecessary interference.
Abstract:
A technique for receiving a data stream including a spreading sequence packet of information containing a data payload and, in addition to the data payload, packet overhead including at least periodic information and at least one unique section of known coded information that defines a unique position within the packet, includes performing a plurality of processing steps to detect the position of the unique section within the packet of information. The steps include detecting the periodicity of the periodic information in a first processing step; in a second processing step after periodicity in the received data stream has been determined, estimating the position of the unique section within the packet of information; and in a third processing step, correlating the information in the packet of information about the estimated position with the known coded information.
Abstract:
A subscriber access unit includes a transceiver for providing wireless communication of digital signals. The digital signals are communicated to a base station using at least one radio frequency (RF) channel via Code Division Multiple Access (CDMA) modulated radio signals defined by orthogonal codes. Orthogonal subchannels are made available by the base station within each CDMA RF channel. A bandwidth manager is connected to the transceiver, and when the transceiver is actively sending data, at least one orthogonal subchannel is allocated by the base station on an as-needed basis. The number of orthogonal subchannels being allocated changes during a given session. The transceiver, when powered on but not actively sending data, provides an idling mode connection on a reverse link. The idling mode connection is based on an orthogonal subchannel shared with at least one other subscriber access unit, but utilizes different time slots of the shared orthogonal subchannel.
Abstract:
A single chip radio platform is disclosed for communicating with an RF channel. An RF front end is provided having a receive/transmit capability to receive an RF carrier modulated with digital data and convert the data to analog baseband data, and modulate an RF carrier with baseband data. A digital signal processor (DSP) engine is provided for interfacing with the RF front end to form in conjunction therewith the PHY layer, and interfacing with the MAC layer to demodulate the baseband data and in the transmit mode to generate the baseband data for modulation and transmission by the RF front end. A microcontroller unit (MCU) is provided for performing the functionality of the MAC, network and application layers and interfacing with the DSP. Clock circuitry is provided including a stable reference clock for generating a first fixed clock for providing MCU clocks for the operation of the MCU, and for providing a reference for a local oscillator at substantially the channel frequency for use by the RF front end and a DSP clock for use by the DSP, both the MCU clocks, the local oscillator and the DSP clock having the stability of the first fixed clock. Periodic power management circuitry is provided for controlling the operation of the radio platform to operate in a sleep.
Abstract:
Quick frequency tracking (QFT), quick time tracking (QTT), and non-causal pilot filtering (NCP) are used to detect sporadically transmitted signaling, e.g., paging indicators. For QFT, multiple hypothesized frequency errors are applied to an input signal to obtain multiple rotated signals. The energies of the rotated signals are computed. The hypothesized frequency error with the largest energy is provided as a frequency error estimate. For QTT, coherent accumulation is performed on the input signal for a first set of time offsets, e.g., early, on-time, and late. Interpolation, energy computation, and non-coherent accumulation are then performed to obtain a timing error estimate with higher time resolution. For NCP, pilot symbols are filtered with a non-causal filter to obtain pilot estimates for one antenna for non-STTD and for two antennas for STTD. The frequency and timing error estimates and the pilot estimates are used to detect the signaling.
Abstract:
A time division duplex/code division multiple access user equipment receives a plurality of communication bursts transmitted in a time slot. A midamble code included in a received communication burst is determined. A channelization code of a determined midamble's communication burst is determined. A mapping between channelization codes and midamble codes exists such that each midamble being mapped to at least one channelization code and at least one midamble code being mapped to at least two channelization codes which may be received in communication bursts simultaneously.
Abstract:
Disclosed is a mobile communication terminal employing a code division multiple access scheme, in which when it is decided that the common channel level is equal to or higher than a third threshold (common channel level threshold), an RLF decision control unit compares the SIR data with a first threshold and a second threshold to decide in sync state/out-of sync state between the local spread code and the reception spread code and outputs the decision signal. When it is decided that the common channel level is lower than the third threshold, the first threshold and the second threshold are set to the same value. In this state, when it is decided that the level of the SIR data is lower than the first threshold (=second threshold), the decision signal corresponding to an out-of sync state is output immediately after a predetermined delay time elapses, thereby reducing the power dissipation.
Abstract:
Provided are a terminal performing a wake-up with consumption of low power and a wake-up method performed by the terminal. The terminal includes: a passive filter outputting a correlation signal between a received signal and a reference signal; and a wake-up controller controlling whether to wake up a communication module, using the correlation signal output from the passive filter. Thus, a wake-up signal can be processed using the passive element that does not consume power during its operation. Also, a wake-up of a communication module can be controlled using the result of processing the wake-up signal. As a result, power consumption can be greatly reduced during the wake-up.