Abstract: A method for operating an access point in a wireless local area network (WLAN) is provided. The access point includes a directional antenna for communicating with at least one remote station in a forward link based upon an exchange of packet data comprising a plurality of control frames and a data frame. The directional antenna includes a plurality of antenna patterns. The method includes receiving a first control frame via a first antenna pattern of the directional antenna from the remote station, transmitting a first data frame to the remote station, and receiving a second control frame via a second antenna pattern of the directional antenna from the remote station. A signal quality of the first control frame received via the first antenna pattern and a signal quality of the second control frame received via the second antenna pattern are measured. The respective measured signal qualities associated with the first and second antenna patterns are compared.

Abstract: A control channel supporting traffic control in epochs is divided into two control subchannels each being less than or equal to about a half epoch in duration and occurring serially in time. Slot allocation data may be transmitted and received independently over the subchannels. One subchannel may be used for transmitting forward slot allocation data and the other subchannel may be used for transmitting reverse slot allocation data. The channel split into two subchannels may be a paging channel. The forward and reverse slot allocation data may be transmitted between a base station processor and field unit. Forward and reverse traffic data may be staggered by at least about half an epoch. Transmission of traffic data happens within about two epochs after the assignments.

Abstract: A method for operating an access point in a wireless local area network is provided, wherein the access point includes a directional antenna for communicating with at least one remote station. The method includes communicating with a selected remote station using a current angle of the directional antenna, and scanning an alternate angle from a plurality of alternate angles of the directional antenna for communicating with the selected remote station. Respective signals received via the current angle and the alternate angle from the selected remote station are measured. The current angle or the alternate angle is selected as a preferred angle based upon the measured signals for continuing communications with the selected remote station.

Abstract: An antenna control interface is integrated with common integrated circuit components, such as radio transceiver or baseband modem signal processing control logic. The antenna control interface controls the operation of an adaptive antenna array used with wireless communication system devices.

Abstract: The present invention provides for making code rate adjustments and modulation type adjustments in a pseudonoise (PN) encoded CDMA system. Coding rate adjustments may be made by changing the number of information bits per symbol, or Forward Error Code (FEC) coding rate. A forward error correction (FEC) block size is maintained at a constant amount. Therefore, as the number of information bits per symbol are increased, an integer multiple of bits per epoch is always maintained. The scheme permits for a greater flexibility and selection of effective data rates providing information bit rates ranging from, for example, approximately 50 kilobits per second to over 5 mega bits per second (Mbps) in one preferred embodiment.

Abstract: A technique for encoding digital communication signals. Data symbols are augmented in pilot symbols inserted at predetermined positions. The pilot augmented sequence is then fed to a deterministic error correction block encoder, such as a turbo product coder, to output a coded sequence. The symbols in the error correction encoded sequence are then rearranged to ensure that the output symbols derived from input pilot symbols are located at regular, predetermined positions. As a result, channel encoding schemes can more easily be used which benefits from power of two length block sizes.

Abstract: A technique for efficient implementation of pilot signals on a reverse link in a wireless communication system. An access channel is defined for the reverse link such that within each frame, or epoch, a portion is dedicated to sending only pilot symbols. Another portion of the frame is reserved for sending mostly data symbols; however, within this second portion of the frame, additional pilot symbols are interleaved among the data symbols. The pilot symbol or preamble portion of the access channel frame allows for efficient acquisition of the access signal at the base station, while providing a timing reference for determining the effects of multipath fading. In particular, a pilot correlation filter provides a phase estimate from the pilot symbols in the preamble portion, which is then used to decode the data symbols in the payload portion. An access acquisition portion of the receiver uses the phase estimates provided by the pilot correlation filter to process the output of a data symbol correlation filter.

Abstract: A control channel supporting traffic control in epochs is divided into two control subchannels each being less than or equal to about a half epoch in duration and occurring serially in time. Slot allocation data may be transmitted and received independently over the subchannels. One subchannel may be used for transmitting forward slot allocation data and the other subchannel may be used for transmitting reverse slot allocation data. The channel split into two subchannels may be a paging channel. The forward and reverse slot allocation data may be transmitted between a base station processor and field unit. Forward and reverse traffic data may be staggered by at least about half an epoch. Transmission of traffic data happens within about two epochs after the assignments.

Abstract: The present invention provides for making code rate adjustments and modulation type adjustments in a pseudonoise (PN) encoded CDMA system. Coding rate adjustments may be made by changing the number of information bits per symbol, or Forward Error Code (FEC) coding rate. A forward error correction (FEC) block size is maintained at a constant amount. Therefore, as the number of information bits per symbol are increased, an integer multiple of bits per epoch is always maintained. The scheme permits for a greater flexibility and selection of effective data rates providing information bit rates ranging from, for example, approximately 50 kilobits per second to over 5 mega bits per second (Mbps) in one preferred embodiment.

Abstract: A system and method for encoding/decoding data channels in a CDMA system having data channel interference cancellation, wherein data channel interference cancellation is used to remove unwanted non-orthogonal pilot signal components which are present within a demodulated data signal. This is accomplished by regenerating interference terms with respect to the non-orthogonal pilot signal and subtracting them from the demodulated data signal.

Abstract: A technique for efficient implementation of pilot signals on a reverse link in a wireless communication system. An access channel is defined for the reverse link such that within each frame, or epoch, a portion is dedicated to sending only pilot symbols. Another portion of the frame is reserved for sending mostly data symbols; however, within this second portion of the frame, additional pilot symbols are interleaved among the data symbols. The pilot symbol or preamble portion of the access channel frame allows for efficient acquisition of the access signal at the base station, while providing a timing reference for determining the effects of multipath fading. In particular, a pilot correlation filter provides a phase estimate from the pilot symbols in the preamble portion, which is then used to decode the data symbols in the payload portion. An access acquisition portion of the receiver uses the phase estimates provided by the pilot correlation filter to process the output of a data symbol correlation filter.

Abstract: A technique for encoding digital communication signals. Data symbols are augmented in pilot symbols inserted at predetermined positions. The pilot augmented sequence is then fed to a deterministic error correction block encoder, such as a turbo product coder, to output a coded sequence. The symbols in the error correction encoded sequence are then rearranged to ensure that the output symbols derived from input pilot symbols are located at regular, predetermined positions. As a result, channel encoding schemes can more easily be used which benefits from power of two length block sizes.

Abstract: A system and method for encoding/decoding data channels in a CDMA system having data channel interference cancellation, wherein data channel interference cancellation is used to remove unwanted non-orthogonal pilot signal components which are present within a demodulated data signal. This is accomplished by regenerating interference terms with respect to the non-orthogonal pilot signal and subtracting them from the demodulated data signal.

Abstract: A technique for steering a directional antenna such as may be used with User Equipment (UE) in a wireless communication system. Optimum angle settings for the directional antenna are determined as different values for an uplink and downlink; that is for simple reception and simple transmission. Thus, rather than determine compromised directions that are picked in an attempt to optimize transmission and reception with the same directional setting, directional settings may be optimized independently. The invention is of particular use in a Time Division Duplex (TDD) system where transmit and receive functions can be operating independently at different times. In further aspects, an optimum direction is determined by estimating an interference signal power which is detected from signals emanating from adjacent base stations (access points) and determining a directional setting that minimizes interference to adjacent cells based upon such measurements.

Abstract: An antenna for use with a receiver in a wireless communications system includes antenna elements for generating antenna patterns, and a first module for applying weights to a signal received at each of the antenna elements to generate a selected one of the antenna patterns. A second module detects the received signal at each of the antenna elements. A combiner combines the received signal detected at each of the antenna elements to produce a combined received signal for a selected antenna pattern. A third module determines a signal quality metric for the combined received signal at each selected antenna pattern. The first module is responsive to the determined signal quality metrics for adjusting the weights to generate a preferred antenna pattern.

Abstract: A single, common correlation filter (CF) core is provided in a wireless system using CDMA. A plurality of channels with different data rates are provided in the wireless system. The channels provided in the wireless system include the access channel, the maintenance channel, and the traffic channel in which information (e.g., pilot or data symbols or both) is transmitted at the tier 1, tier 2 and tier 3 rates. The data rate for transmitting the information is programmable by digital signal processor (DSP). A user-unique code, such as a PN code, is applied to the information being transmitted in the channels of the wireless system. The information is QPSK modulated and transmitted in any one of the channels at any data rate. The transmitted information is correlated at the smallest data rate (i.e., the tier 1 rate) in the correlation filter (CF) of the wireless system by time multiplexing delayed versions of the PN code to the correlation filter core.

Abstract: A personal computer's (PC) microprocessor is used to provide both the physical layer (PHY) and media access control (MAC) processing functions required to implement a wireless local area network (WLAN) adapter. This technique uses the microprocessor within the personal computer to pre-compute the time critical PHY waveforms required to respond to received packets. For instance, the acknowledge (ACK) waveform required to respond to a received WLAN packet is pre-computed and stored in the PC memory. Upon receipt of a valid packet, the samples of the ACK waveform are transferred from the PC memory to a digital to analog converter (DAC). The DAC generates the transmit waveform required for the radio modulator. By pre-computing the transmit waveform samples, the required loading on the PC microprocessor is reduced during time critical periods.

Abstract: A method for synchronizing a CDMA receiver to a transmitter when an adaptive antenna is utilized to receive transmitted data, wherein a receiving antenna system is adapted between a 360° reception angle pattern (i.e., an omni-directional pattern) and a fixed reception angle (i.e., a directional pattern) by permitting the receiver to identify a pilot signal having the largest magnitude. The receiver minimizes interference from other pilot signals by steering antenna pattern nulls toward other transmitters. As a result, the time required for the receiver to acquire a valid pilot signal is significantly reduced.

Abstract: A Station Management Entity (SME) steers a directional antenna for a station to communicate with an Access Point (AP) in an 802.11 protocol system. The SME can steer the antenna before or after an 802.11 station has authenticated and associated with the Access Point. During a passive scan, the steering process cycles through the available antenna positions and monitors an AP beacon signal to determine a best position based on, for example, a Received Signal Strength Indication (RSSI). During an active scan where access probing is used, the steering process cycles through the antenna positions and monitors a probe response to determine the best antenna position. Additional scans may be performed based on a decision that the received signal level of the currently selected antenna position has dropped below a predetermined threshold.

Abstract: The present invention provides for making code rate adjustments and modulation type adjustments in a pseudonoise (PN) encoded CDMA system. Coding rate adjustments may be made by changing the number of information bits per symbol, or Forward Error Code (FEC) coding rate. A forward error correction (FEC) block size is maintained at a constant amount. Therefore, as the number of information bits per symbol are increased, an integer multiple of bits per epoch is always maintained. The scheme permits for a greater flexibility and selection of effective data rates providing information bit rates ranging from, for example, approximately 50 kilobits per second to over 5 mega bits per second (Mbps) in one preferred embodiment.