Abstract: Systems and methodologies are described that facilitate calibrating an antenna array in a wireless network by generating a copy of a transmitted signal or transmitted signal from a transmit chain of an antenna and providing it to a receive chain of one or more antennas in the array for comparison to obtain a gain mismatch measurement. Such comparisons can be performed for each antenna in the array to facilitate obtaining multiple measurements, upon which gain mismatch estimations can be generated.

Abstract: To select a rate for a transmitter in a communication system, a receiver obtains a channel response estimate and a received SINR estimate for the transmitter, e.g., based on a pilot received from the transmitter. The receiver computes a hypothesized SINR for the transmitter based on the channel response estimate and the received SINR estimate. The receiver then selects a rate for the transmitter based on (1) the hypothesized SINR and (2) characterized statistics of noise and interference at the receiver for the transmitter, which may be given by a probability density function (PDF) of SINR loss with respect to the hypothesized SINR. A look-up table of rate versus hypothesized SINR may be generated a priori for the PDF of SINR loss. The receiver may then apply the hypothesized SINR for the transmitter to the look-up table, which then provides the rate for the transmitter.

Abstract: Techniques for controlling transmit power and the amount of overlapping in a quasi-orthogonal system are described. A base station for a sector receives transmissions from terminals in that sector and neighbor sectors and determines performance metrics (e.g., overall throughput) and/or QoS metrics (e.g., minimum data rate) for the terminals in the sector. The base station updates an overlapping factor based on the performance metrics and updates a QoS power control parameter based on the QoS metrics. The overlapping factor indicates the average number of overlapping transmissions sent simultaneously on each time-frequency block usable for data transmission. The QoS power control parameter ensures that the terminals in the sector can achieve minimum QoS requirements. A power control mechanism with multiple loops is used to adjust the transmit power of each terminal. The overlapping factor and QoS power control parameter are updated by two of the loops.

Abstract: Transmission patterns for pilot symbols transmitted from a mobile station or base station are provided. The pattern allows for improved receipt of the pilot symbols transmitted. In addition, schemes for improving the ability to multiplex pilot symbols without interference and/or biasing from different mobile stations over the same frequencies and in the same time slots.

Abstract: Transmission patterns for pilot symbols transmitted from a mobile station or base station are provided. The pattern allows for improved receipt of the pilot symbols transmitted. In addition, schemes for improving the ability to multiplex pilot symbols without interference and/or biasing from different mobile stations over the same frequencies and in the same time slots.

Abstract: A channel structure has at least two channel sets. Each channel set contains multiple channels and is associated with a specific mapping of the channels to the system resources available for data transmission. Each channel set may be defined based on a channel tree having a hierarchical structure. To achieve intra-cell interference diversity, the channel-to-resource mapping for each channel set is pseudo-random with respect to the mapping for each remaining channel set. In each scheduling interval, terminals are scheduled for transmission on the forward and/or reverse link. The scheduled terminals are assigned channels from the channel sets. Multiple terminals may use the same system resources and their overlapping transmissions may be separated in the spatial domain. For example, beamforming may be performed to send multiple overlapping transmissions on the forward link, and receiver spatial processing may be performed to separate out multiple overlapping transmissions received on the reverse link.

Abstract: Transmission patterns for pilot symbols transmitted from a mobile station or base station are provided. The pattern allows for improved receipt of the pilot symbols transmitted for frequency selective channels and users. In addition, schemes for improving the ability to multiplex pilot symbols without interference and/or biasing from different mobile stations over the same frequencies and in the same time slots.

Abstract: In connection with transmitted space-time, trellis encoded, signals that pass through a transmission channel that is characterized by memory, improved performance is realized with a receiver that combines a decoder with an equalizer that selects the trellis transition, s, that minimizes the metric ? j ? ( k ) = ? r ? ( k ) - ? l = L 1 + 1 L 1 ? h ~ j ? ( l ) ? s ~ ? ( k - l ) - ? l = L 1 + 1 L + 1 ? h ~ j ? ( l ) ? s ^ ? ( k - l ) ? 2 where {tilde over (h)}j(l) is related to both the transmission channel and to the encoding structure in the transmitter, {tilde over (s)}(k) are the (trial) symbols according to a certain transition and ?(k) are the symbols that were previously decided.

Abstract: Transmitters, receivers, and methods for providing improved transmit diversity orthogonal frequency division multiplexed communication systems is provided.

Abstract: Methods and apparatuses that apply a time-varying delay to symbols to be transmitted from one or more antennas are provided.

Abstract: Systems and methods for controlling transmission power are provided. The systems and methods vary the power of a signal provided to a power amplifier based upon the location of a frequency or frequencies of signals to be transmitted within the transmission frequency band, the location of a hop region within the transmission frequency band, the bandwidth of signals to be transmitted, or combinations of these approaches.

Abstract: A method and apparatus for increasing the data rate and providing antenna diversity using multiple transmit antennas is disclosed. A set of bits of a digital signal are used to generate a codeword. Codewords are provided according to a channel code. Delay elements may be provided in antenna output channels, or with suitable code construction delay may be omitted. n signals represent n symbols of a codeword are transmitted with n different transmit antennas. At the receiver MLSE or other decoding is used to decode the noisy received sequence. The parallel transmission and channel coding enables an increase the data rate over previous techniques, and recovery even under fading conditions. The channel coding may be concatenated with error correction codes under appropriate conditions.

Abstract: Block-encoded transmissions of a multi-antenna terminal unit are effectively detected in the presence of co-channel interfering transmissions when the base station has a plurality of antennas, and interference cancellation is combined with maximum likelihood decoding. More specifically, the signals received at the base station antennas are combined in a linear combination that relates to the channel coefficients between the various transmitting terminal units and the base antennas. By selecting proper coefficients for the linear combination and choosing probable transmitted signals that minimize a minimum mean squared error function, the signals of the various terminal units are canceled when detecting the signal of a particular unit. In another embodiment of the invention, the basic approach is used to obtain an initial estimate of the signals transmitted by one terminal unit, and the contribution of those signals is removed from the received signals prior to detecting the signals of other terminal units.

Abstract: Noise and interference can be independently measured in a multiple user Orthogonal Frequency Division Multiplexing (OFDM) system. Co-channel interference is measured in a frequency hopping, multiple user, OFDM system by tracking the sub-carriers assigned to all users in a particular service area or cell. The composite noise plus interference can be determined by measuring the amount of received power in a sub-carrier whenever it is not assigned to any user in the cell. A value is stored for each sub-carrier in the system and the value of noise plus interference can be a weighted average of the present value with previously stored values. The noise component can be independently determined in a synchronous system. In the synchronous system, all users in a system may periodically be prohibited from broadcasting over a sub-carrier and the received power in the sub-carrier measured during the period having no broadcasts.