Abstract: Techniques for performing decision feedback equalization are described. A feed-forward filter response and a feedback filter response are derived based on a channel estimate and a reliability parameter and further without constraint on the feedback filter response or with a constraint of no feedback for an on-time sample. The reliability parameter is indicative of the reliability of the feedback used for equalization and may be frequency dependent or frequency invariant. Different feed-forward and feedback filter responses may be derived with different constraints on the feedback filter and different assumptions for the reliability parameter. Equalization is performed with the feed-forward and feedback filter responses.

Abstract: Techniques for multiplexing pilots in a wireless transmission are described. In one aspect, a transmitter station generates multiple pilot sequences for multiple transmit antennas, with each pilot sequence comprising pilot symbols sent in the time domain on a different set of subcarriers. The transmitter station further generates multiple pilot transmissions for the transmit antennas based on the pilot sequences. In another aspect, a transmitter station generates multiple pilot sequences for multiple transmit antennas based on frequency-domain code division multiplexing (FD-CDM) of a Chu sequence defined by a transmitter-specific value. The transmitter station further generates multiple pilot transmissions for the transmit antennas based on the pilot sequences.

Abstract: Techniques for performing space-frequency equalization and spatial equalization in the frequency domain are described. Space-frequency equalization combines signal components across both space and frequency dimensions whereas spatial equalization combines signal components across space. A receiver obtains input symbols for multiple (M) signal copies from multiple (R) receive antennas and multiple (C) times oversampling, where M is equal to R times C. For space-frequency equalization, the receiver derives equalizer coefficients for the M signal copies, e.g., based on MMSE criterion, filters, the input symbols for the M signal copies with the equalizer coefficients, and combines the filtered symbols for the M signal copies to obtain output symbols. Space-frequency equalization may be used for some frequency bins and spatial equalization may be used for other frequency bins to reduce complexity.

Abstract: An equalization filter is provided with the ability to softly switch between pure linear equalization and decision feedback equalization. A reliability gain factor and an associated gain factor calculated by a predetermined mapping relation are provided in a decision feedback path and a feedforward path, respectively. Increasing the reliability gain factor increases the significance of the decision feedback filtering. Better performance than pure linear equalization and pure decision feedback equalization can be achieved.

Abstract: Techniques for transmitting and receiving data in an efficient manner to potentially improve capacity for a wireless network and achieve power savings for a wireless device are described. The techniques utilize a Continuous Packet Connectivity (CPC) mode comprised of multiple (e.g., two) discontinuous transmission (DTX) modes and at least one (e.g., one) discontinuous reception (DRX) mode. Each DTX mode is associated with different enabled uplink subframes usable for transmission from the wireless device to the network. Each DRX mode is associated with different enabled downlink subframes usable by the network for transmission to the wireless device. The wireless device may send signaling and/or data on the enabled uplink subframes and may receive signaling and/or data on the enabled downlink subframes. The wireless device may power down during non-enabled subframes to conserve battery power. Mechanisms to quickly transition between the DTX and DRX modes are described.

Abstract: A method and apparatus manages resources in a wireless communication system by transmitting a multi-carrier switch command message to an access terminal instructing the access terminal to switch between a diversity mode where each antenna module of a plurality antenna modules receives a single carrier signal transmitted at a single carrier frequency and a multi-carrier mode where a first antenna module of the plurality antenna modules receives a first multi-carrier signal transmitted at a first carrier frequency and a second antenna module receives a second multi-carrier signals transmitted at a second carrier frequency.

Abstract: In one disclosed embodiment, an input bit stream is supplied to a trellis code block. For example, the trellis code block can perform convolutional coding using a rate 6/7 code. The output of the trellis code block is then modulated using, for example, trellis coded quadrature amplitude modulation with 128 signal points or modulation symbols. The sequence of modulation symbols thus generated can be diversity encoded. The diversity encoding can be either a space time encoding, for example, or a space frequency encoding. The sequence of modulation symbols, or the sequence of diversity encoded modulation symbols, is fed to two or more orthogonal Walsh covers. For example, replicas of the modulation symbol sequences can be provided to increase diversity, or demultiplexing the modulation symbol sequences can be used to increase data transmission rate or “throughput.” The outputs of the Walsh covers are fed as separate inputs into a communication channel.

Abstract: Techniques for transmitting data in a manner to facilitate equalization at a receiver are described. Guard intervals are appended to data blocks such that each data block has a guard interval at the beginning of the data block and a guard interval at the end of the data block. Each guard interval may be discontinuous transmission (DTX), a polyphase sequence, or some other known sequence. Pilot is appended to each set of at least one data block. The data blocks, pilot, and guard intervals may be sent using various slot structures and are processed for transmission. The processing may include mapping the data blocks to at least one physical channel, channelizing the data blocks for each physical channel with a channelization code, combining all physical channels, and scrambling the combined data, pilot, and guard intervals with a scrambling code.

Abstract: A method and an apparatus for recovery of particular bits in a frame are disclosed. An origination station forms a frame structure with groups of information bits of different importance. All the information bits are then protected by an outer quality metric. Additionally, the groups of more important information bits are further protected by an inner quality metric; each group having a corresponding quality metric. The frame is then transmitted to a destination station. The destination station decodes the received frame and decides, first in accordance with the outer quality metric, whether the frame has been correctly received, or whether the frame is erased. If the frame has been declared erased, the destination station attempts to recover the groups of more important information bits in accordance with the corresponding inner quality metrics.

Abstract: Collisions between messages simultaneously transmitted by multiple spread-spectrum transmitters are reduced by distributing the transmissions over the available resources of the receiver. Each mobile station in a CDMA system uses one or more randomization methods to distribute its transmissions. In the first randomization, the mobile station time-delays its transmissions by a number of chips of the PN code with which it spreads the transmitted signal. In a second randomization, the mobile station randomly selects the PN code. In a third randomization, the mobile station inserts a random delay between successive message transmissions or probes if it does not receive an acknowledgement after a predetermined timeout period. A predetermined number of such transmissions is called a probe sequence. In a fourth randomization, the mobile station inserts a relatively long random delay between successive probe sequences if it does not receive an acknowledgement of any probe in the sequence.

Abstract: Method and apparatus for determining a transmission configuration for a dedicated channel in a wireless communication system. In one embodiment, an optimum configuration is determined based on minimizing Peak-to-Average Ratio (PAR) of the channel. The configuration is defined as a transmission pair of transmission branch and spreading code. The transmission branch may be the In-Phase (I) branch or the Quadrature (Q) branch. PAR analysis may be performed off-line to determine the optimum configuration. In operation, if the spreading code of the optimum configuration is used by another channel, the next best optimum code is used.

Abstract: Methods and apparatus are presented for improving the feedback of channel information to a serving base station, which allows a reduction in the reverse link load while allowing the base station to improve the forward link data throughput. Over a channel quality indicator channel, three subchannels are generated; the re-synch subchannel, the differential feedback subchannel, and the transition indicator subchannel. The information carried on each subchannel can be used separately or together by a base station to selectively update internal registers storing channel conditions. The channel conditions are used to determine transmission formats, power levels, and data rates of forward link transmissions.

Abstract: A base station (LBS) (110) in a wireless network (100) establishes power levels for transmitting messages acknowledging receipt of packet data from a mobile communications device (MAD) (114). In one implementation, the LBS infers whether the MAD received a given acknowledgement message by considering whether (306, 316) the next communication from the MAD comprises new packet data, and whether (310, 320) that data comprises re-transmitted data. The LBS adjusts (312, 314, 322, 324) transmit power level for future acknowledgement messages according to whether the MAD received past acknowledgement messages. In a different implementation, actual/estimated transmit power from a serving base station to a given MAD is averaged (404), and increased (406) by a prescribed amount to yield a target level. Whenever the non-serving base station transmits messages acknowledging receipt of packet data from the MAD, the non-serving base station transmits (408) at the target level.

Abstract: A method and apparatus for maximizing the use of available capacity in a communication system. The forward link in the mobile radio system includes a plurality of traffic streams sent on at least one channel from the base station to the mobile stations. A first output power level associated with simultaneously transmitting a first set of traffic streams from the base station to the mobile stations on the forward link is initially determined. Next, the first output power level is compared to the maximum power ceiling. In response to the comparing step, at least one time frame in the forward link having available capacity for transmitting a portion of at least one further traffic stream is identified. The first set of traffic streams and the portion of the at least one further traffic stream are then transmitted simultaneously during the at least one frame on the forward link.

Abstract: In a communication system, a method and an accompanying apparatus determine a number of available fingers (110A-N) in a receiver (100). A controller (121) adjusts a threshold based on the determined number of the available fingers (110). The adjusted threshold may be one of, or any combination of, a pilot signal search threshold, a lock/unlock threshold, and a combine/un-combine threshold. The number of available fingers (110) may change after the threshold is adjusted.