Abstract: Various methods and systems receiving information from an access point over a wireless link in order to reduce processing and/or transmission overhead are disclosed. Such methods and systems may include the processing of a received packet using a descrambling operation on at least a portion of the packet's information based on a MAC-ID associated with an access terminal to produce at least a first processed packet, and determining whether the received packet is targeted to the access terminal based on the first processed packet.

Abstract: Techniques to transmit pilot on a CDMA segment on the reverse link in a wireless communication system are described. A terminal generates a scrambling sequence based on its pilot information. The pilot information may be used for the entire duration of a call by the terminal and for all sectors with which the terminal communicates during the call. The terminal generates pilot symbols based on the scrambling sequence, maps the pilot symbols to the CDMA segment, generates OFDM symbols with the mapped pilot symbols, and sends the OFDM symbols to one or more sectors. A base station processes received OFDM symbols to obtain received symbols for the CDMA segment. The base station generates the scrambling sequence based on the pilot information for the terminal and processes the received symbols with the scrambling sequence to obtain at least one parameter (e.g., received signal strength) for the terminal.

Abstract: Techniques for controlling transmit power of a terminal are described. The terminal may send a first transmission (e.g., for pilot or signaling) on the reverse link, receive feedback (e.g., a power control command or an erasure indicator) for the first transmission, and adjust a reference power level based on the feedback. The terminal may also receive interference information and possibly other parameters such as a pilot quality indicator (PQI), an offset factor, and a boost factor from a sector. The terminal may determine transmit power for a second transmission to the sector based on the interference information, the reference power level, and/or the other parameters. The terminal may receive the feedback from one sector and may send the second transmission with CDMA or OFDMA to the same sector or a different sector.

Abstract: Various methods and systems receiving information from an access point over a wireless link in order to reduce processing and/or transmission overhead are disclosed. Such methods and systems may include the processing of a received packet using a descrambling operation on at least a portion of the packet's information based on a MAC-ID associated with an access terminal to produce at least a first processed packet, and determining whether the received packet is targeted to the access terminal based on the first processed packet.

Abstract: Techniques for selecting serving sectors and performing handoff for a terminal on the forward and reverse links are described. The terminal may obtain pilot measurements for pilots transmitted on the forward link and may update an active set based on the pilot measurements. The terminal may send a transmission (e.g., for pilot, signaling, etc.) on the reverse link and may receive channel quality information indicative of reverse link channel quality for the terminal at multiple sectors in the active set. The transmission may include pilot, and the channel quality information from each sector may include a pilot carrier-over-thermal ratio (pCoT) determined by that sector based on the pilot. The terminal may select a serving sector based on the channel quality information, interference information, and/or other information and may send a request for handoff (e.g., via a signaling message an/or an access probe) to the selected serving sector.

Abstract: A apparatus and method for improved performance in radio telecommunications systems, and in particular multi-carrier code division multiple access (MC-CDMA) networks that employ pulse-shaping filters on the transmit side of a radio link. In order to more accurately transmit a radio signal bearing a symbol sequence, the modulated and spread information stream is upsampled using a technique that involves inserting zeros in the frequency domain. A corresponding downsampling procedure on the receive side permits reconstruction of the transmitted symbols. A new channel estimation algorithm may also be used, and the improved channel estimation advantageously employed to obtain more faithful symbol detection.

Abstract: Systems and methodologies are described that facilitate soft handoff and enhanced performance in a wireless communication environment. In multiple access systems, access points assign certain resources (e.g., time, frequency, code) to each terminal. This assignment information can also be provided to neighboring sectors, allowing such sectors to receive and decode terminal transmissions. The information can be provided via backhaul signaling. Decoding by sectors within the active set of the terminal facilitates smooth transition as terminals move between sectors during soft handoff. In addition, sectors can signal successful receipt and decoding of transmissions, avoiding redundant processing.

Abstract: Techniques for performing power control and handoff are described. In an aspect, power control (PC) is supported with multiple PC modes such as an up-down PC mode and an erasure-based PC mode. One PC mode may be selected for use. Signaling may be sent to indicate the selected PC mode. If the up-down PC mode is selected, then a base station estimates the received signal quality for a terminal and sends PC commands to direct the terminal to adjust its transmit power. If the erasure-based PC mode is selected, then the base station sends erasure indications that indicate whether codewords received from the terminal are erased or non-erased. For both PC modes, the terminal adjusts its transmit power based on the power control feedback (e.g., PC commands and/or erasure indications) to achieve a target level of performance (e.g., a target erasure rate for the codewords). The erasure indications may also be used for handoff.

Abstract: Systems and methodologies are described that facilitate serving sector directed transmit power control in a wireless communication environment. Under certain conditions, an access point can have better data with which to determine appropriate power levels than an individual terminal. Accordingly, an access point can transmit power control information to one or more terminals supported by the access point overriding normal power determination procedures. In particular, power control information can be included within an assignment message that designates resources (e.g., frequency, time) assigned to a terminal. Power control information can be based upon SNR, quality of service requirements, interference information, any other relevant information or any combination thereof.

Abstract: A terminal communicates with a serving base station and at least one soft handoff (SHO) base station for soft handoff on the reverse link in a wireless communication system. In one design, the serving base station schedules the terminal for transmission on the reverse link, forms an assignment for the terminal, and generates signaling for the terminal. The assignment indicates communication parameter(s) to be used by the terminal for transmission on the reverse link. The signaling contains sufficient information to allow the SHO base station(s) to receive and process the transmission from the terminal. The serving base station sends the signaling via a backhaul to the SHO base station(s). Each SHO base station receives the signaling via the backhaul, receives the transmission from the terminal via the reverse link, and processes the transmission in accordance with the signaling to recover the data sent in the transmission.

Abstract: The system and method utilize design criteria and construction for signal constellations in communication systems, such as cellular telephony, that have imperfect channel state information at the receiver. The system and method assume an imperfect knowledge of fading channel state information (600B) and statistics of channel fading (600D) are used to encode additional information into the space-time matrix signal constellation as variations in amplitude of constellation (600E) points. In the preferred embodiment space-time matrix constellations and design criterion are based on the Kullback-Leibler distance between conditional distributions.

Abstract: A first data symbol that includes a kth data bit is received over a multicarrier system. A first channel quality parameter is estimated for the first data symbol. A second data symbol that includes a retransmitted kth data bit is received. A second channel quality parameter for the second data symbol is estimated. A probable value of the kth data bit is determined based on both the first channel quality parameter and the second channel quality parameter. In response to an ARQ for data symbols communicated over a multicarrier system, the following are performed: determining channel quality parameters, each of the channel quality parameters corresponding to at least one of the transmitted data symbols; selecting a subset of the channel quality parameters exhibiting a worst quality; constructing a block of data symbols corresponding to the subset; and communicating the block of data symbols over a plurality of subcarriers.

Abstract: A generalized zigzag code is described where the code segments (each including one parity bit and information bits) of a block are not necessarily of uniform length. For coding rates in which the average code segment length is not an integer, all code segment lengths may be identical. The number of code segments depends on the coding rate and number of information bits in a block. At the encoder, parity bits are added to each string of information bits in a block to yield the code segments. For a punctured code, concatenated or not, the encoder may remove or not generate the punctured parity bits. At a decoder that operates at a rate different from the code rate of a received block, null parity bits are inserted. The received block has a number of code segments. The decoder increases the number of code segments by the addition of null parity bits, thereby reducing the coding rate to the rate of the decoder. Methods and apparatuses are detailed.

Abstract: A multi-level space time signal constellation that is optimized for use with a multi-carrier, multi-path communication scheme includes points on a first level separated from points on a mutually exclusive second level by a minimum distance that is based on a conditional probability distribution, preferably a Kullback-Leibler (KL) distance. Points within one level may be separated by a Euclidean distance, but spherical levels are rotated relative to one another to maximize a minimum inter-level KL distance. A receiver uses pilot symbols to estimate the channels and two-stage symbol detection, determining in one stage the constellation level and in another stage the point in the level. The receiver calculates a likelihood function based on a conditional distribution which does not reduce to the Euclidean-based nearest-neighbor detector. A single stored constellation may be scaled based on received signal to noise ratio.

Abstract: A signal constellation is optimized for trellis coded modulation in fast fading channels, where the receiver does not have perfect knowledge of the channel parameters. Specifically, the signal constellation is partitioned into 2n mutually exclusive subsets, each preferably defining two points. Points within each subset are separated from one another by a distance between conditional distributions, preferably a Kullback-Leibler (KL) distance. For a block m=k1+k2 of information bits input into a trellis coder 30, the k, bits are trellis encoded into n bits (n>k1) and used to select a subset of the constellation. The k2 bit(s) is/are used to select a particular point within the subset. Because the inter-subset distance between points is a KL distance that is effectively greater than a Euclidean distance, error at the receiver is substantially reduced, especially at higher SNR. Using a KL distance ensures statistics of channel fading are inherent within the signal constellation.

Abstract: A apparatus and method for improved performance in radio telecommunications systems, and in particular multi-carrier code division multiple access (MC-CDMA) networks that employ pulse-shaping filters on the transmit side of a radio link. In order to more accurately transmit a radio signal bearing a symbol sequence, the modulated and spread information stream is upsampled using a technique that involves inserting zeros in the frequency domain. A corresponding downsampling procedure on the receive side permits reconstruction of the transmitted symbols. A new channel estimation algorithm may also be used, and the improved channel estimation advantageously employed to obtain more faithful symbol detection.

Abstract: A system and method for the efficient transmission of information in a code division multiple access (CDMA) wireless telecommunication system. The rate of reliable transmission is increased by implementing an orthogonal frequency-division multiplexing (OFDM) scheme in, for example, a direct-spread CDMA network, resulting in a multi-carrier CDMA (MC-CDMA) system. Information (such as voice and data), is encoded, divided, and spread across the frequency domain, rather than in the time domain as in traditional CDMA; the allowable transmission bandwidth is divided into a number of carriers. Using this scheme, a number of loading parameters such as code rate, data rate, and the number of streams into which the encoded data is divided may be varied to increase the performance of the system. Application of the variable loading parameter may be a function of channel quality, such as the presence of noise or the channel fading state.