Abstract: A technique for steering a directional antenna such as may be used in a Wireless Local Area Network (WLAN) device. The technique detects signal parameters during reception of short sync pulses in the very beginning portion of a Packet Protocol Data Unit (PPDU) frame. As a result, the antenna can be steered to an optimum direction for reception prior to receiving other portions of a preamble that may be needed to acquire carrier signal phase and frequency.

Abstract: Multiple field units in a CDMA system are synchronized for communication with a base station using shared forward and reverse link channels. In an illustrative embodiment, each field unit is assigned a time slot in a forward link channel to receive messages from the base station. Likewise, each field unit is assigned a time slot on a common reverse link channel for transmitting messages to the base station. Timing alignment and power level control among each of many field units and the base station is achieved by analyzing messages received at the base station in a corresponding time slot as transmitted by each field unit. Thereafter, a message is transmitted from the base station in a corresponding time slot to a particular field unit for adjusting its timing or power level so that future messages transmitted from the field unit are received in the appropriate time slot at the base station at a desired power level.

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 communications device includes an antenna array comprising antenna elements for receiving at least N spatially independent signals, and a receiver coupled to the antenna array. The receiver includes an analog receiver circuit for receiving the N spatially independent signals, and has a bandwidth of at least N times an information bandwidth of the spatially independent signals. The receiver further includes a digital receiver circuit coupled to the analog receiver circuit, and samples the N spatially independent signals at a rate of at least N times a Nyquist rate which would have been required if a single antenna element had been used to receive the signals. A processor is coupled to the digital receiver circuit for demultiplexing the sampled N spatially independent signals.

Abstract: Individual RF cables span between element/transceiver pairs in traditional beam forming systems, and the number of elements in an array used for beam forming is thus restricted. To reduce the number of RF cables but maintain or increase the number of elements in an antenna array, an embodiment of the present invention includes electronics at the base of an antenna tower that apply digital multiplexing codes to signals communicated to electronics located at the top of the antenna tower. The electronics at the top demultiplex the signals and transmit them via the antenna array. Received RF signals are processed in a like manner in a reverse direction. Fewer transmission paths (e.g., RF or fiber optic cables) than the number of elements in the antenna array can be used. More antenna elements provide benefits, such as higher user capacity, more antenna beams, narrower antenna beams, and higher in-building penetration.

Abstract: Data rate allocation decisions are made for a communications channel, such as a wireless reverse link connection. A first parameter used in this determination is a path loss, which is determined by the following process. First, a message is sent from a first station to a second station, such as on a paging channel. The message indicates a forward Effective Radiated Power (ERP) of a pilot signal transmitted by the first station. The second station then determines the received signal strength of this pilot signal, taking into account receiver gains. The path loss can then be estimated by the second station as the difference between the forward ERP data value that it received and the detected received pilot power. The second station also then preferably determines a transmit power level when transmitting a message back to the first station. This transmit power level information is encoded as a digital data word together with the forward path loss information as calculated by the first station.

Abstract: A communications device for separating source signals provided by M signal sources includes an antenna array comprising N correlated antenna elements for receiving at least N different summations of the M source signals, with N and M being greater than 1. A receiver is connected to the antenna array for receiving the at least N different summations of the M source signals. A blind signal separation processor is connected to the receiver for forming a mixing matrix comprising up to the at least N different summations of the M source signals, and for separating desired source signals from the mixing matrix. The mixing matrix has a rank equal to at least N.

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 method and system for using watermarks in communication systems is disclosed. Watermarks are typically small amounts of auxiliary data embedded in a cover signal. The cover signal is the primary communication signal, and may be binary bits, multi valued symbols, analog waveforms, or any other type of primary communication signal. Security strength indication, location tracking, intrusion detection and transmission of non-security information using watermarks are disclosed, along with a system for managing watermarks.

Abstract: At least one At least one user data stream is layer 2/3 processed, physical layer processed and radio frequency processed. A watermark/signature is embedded at at least one of layer 2/3, physical layer or radio frequency, producing an embedded wireless communication. The embedded wireless communication is wirelessly transferred. The embedded wireless communication is received and the watermark/signature is extracted from the embedded wireless communication.

Abstract: A spread spectrum method and apparatus for protecting and authenticating wirelessly transmitted digital information using numerous techniques. The apparatus may be a wireless code division multiple access (CDMA) communication system, a base station, a wireless transmit/receive unit (WTRU), a transmitter, a receiver and/or an integrated circuit (IC). The wireless CDMA communication system includes a transmitter which steganographically embeds digital information in a CDMA communication signal and wirelessly transmits the CDMA communication signal. The system further includes a receiver which receives the CDMA communication signal and extracts the steganographically embedded digital information from the received CDMA communication signal.

Abstract: A method and apparatus for protecting and authenticating wirelessly transmitted digital information using numerous techniques. The apparatus may be a wireless orthogonal frequency division multiplexing (OFDM) communication system, a base station, a wireless transmit/receive unit (WTRU), a transmitter, a receiver and/or an integrated circuit (IC). The wireless OFDM communication system includes a transmitter which steganographically embeds digital information in an OFDM communication signal and wirelessly transmits the OFDM communication signal. The system further includes a receiver which receives the OFDM communication signal and extracts the steganographically embedded digital information from the received OFDM communication 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: Tokens/keys are produced for wireless communications. These tokens/keys are used for watermarks, signature insertion, encryption and other uses. In one embodiment, contextual information is used to generate tokens/keys. The tokens/keys may be derived directly from the contextual information. The contextual information may be used in conjunction with other information to derive the tokens/keys. Tokens/keys may be exchanged between transmit/receive units. The exchange of these tokens/keys may be encrypted.

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 a plurality of remote stations, and the directional antenna includes a plurality of antenna patterns. The method includes creating an antenna database by associating between the access point and each remote station a respective measured signal quality corresponding to the plurality of antenna patterns. The respective measured signal qualities are determined by the access point based upon communications with each remote station. The method further includes determining for each remote station a preferred antenna pattern based upon the antenna database, and selecting a remote station and the corresponding preferred antenna pattern to communicate with.

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 a plurality of remote stations, and the directional antenna includes an omni angle and a plurality of directional angles. The method includes selecting one of the remote stations from the plurality of remote stations, transmitting a first probe signal via the omni angle of the directional antenna to the selected remote station, and measuring a first probe response signal received via the omni angle from the selected remote station responding to the first probe signal. A respective second probe signal is transmitted via each one of the plurality of directional angles of the directional antenna to the selected remote station, and a second probe response signal received via each directional angle from the selected remote station responding to the respective second probe signal is measured.

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: 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 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.