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.

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 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 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: 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 determines a preferred direction to the point the directional antenna from the access point to a desired remote station. This determination is based on a sequence of probe signals exchanged between the access point and the remote station. The probe response signals are measured by the access point, and are stored in an antenna database.

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: Codes are applied to signals to reduce the number of transceivers and associated RF cabling extending from base electronics to antenna array electronics in a base station providing beam forming. The transceivers can be reduced to as few as one, and the RF cabling can be reduced to none. The codes may be orthogonal codes, such as Walsh codes. The codes are applied: to weights used to produce the beam forming, signal being transmitted or received, or both. The codes are applied a second time to decompose the coded weights/signal to associate the weights and signal with the beam forming. The coded weights/signal can be summed, including with other coded weights/signals, to produce a composite code division multiplexed signal for transmission between transceiver(s) and antenna array electronics over a single RF or non-RF cable spanning between the base electronics and array electronics.

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 a time division multiplex system in which access to shared broadcast communication media is granted on a demand basis. Particular connections are assigned slot times at the transmitter based on demand. However, no specific information regarding the assignment of time slots need be communicated to the receivers. The transmit side employs a forward error correction technique followed by multiplication by a cover sequence unique to each connection. All receivers listen to the broadcast transmission channel all of the time. The receiver assigned to each connection decodes the signals in such a manner that only the receiver with the correct cover sequence assigned to a particular connection will successfully decode the data associated with that connection. Data frames that fail the forward error correction process are discarded, and only those frames which are successfully decoded are passed up to a higher layer.

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 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 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: An antenna apparatus that can increase capacity in a cellular communication system. The antenna operates in conjunction with a mobile subscriber unit and provides a plurality of antenna elements, each coupled to a respective signal control component such as a phase shifter. The phase shift for each antenna element is programmed for optimum reception during, for example, an idle mode when a pilot signal is received. The antenna array creates a beam former for signals to be transmitted from the mobile subscriber unit, and a directional receiving array to more optimally detect and receive signals transmitted from the base station. By directionally receiving and transmitting signals, multipath fading is greatly reduced as well as intercell interference. The phase shifters are adjusted in a coarse and a fine mode. In the coarse mode all phase shifters are jointly incremented through several phase shift values until a signal quality metric is optimized.

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.