Abstract: A spread-spectrum code division multiple access interference canceller employed by a remote terminal for reducing interference in a direct sequence CDMA receiver having N chip-code channels. The interference canceller includes a plurality of correlators or matched filters, a plurality of spread-spectrum-processing circuits, subtracting circuits, and channel correlators or channel-matched filters. Using a plurality of chip-code signals, the correlators despread the spread-spectrum CDMA signal as despread signals, respectively. The spread-spectrum-processing circuits use a timed version of the chip-code signals, for spread-spectrum processing the despread signals, respectively, with a chip-code-signal corresponding to a respective despread signal. For recovering a code channel using an ith chip-code-signal, the subtracting circuits subtracts from the spread-spectrum CDMA signal, each of the N-1 spread-spectrum-processed-despread signals thereby generating a subtracted signal.

Abstract: A spread-spectrum code division multiple access interference cancellation method for a base station reduces interference in a direct sequence CDMA receiver having N chip-code channels. The interference canceller despreads the spread-spectrum CDMA signal as a plurality of despread signals. A timed version of a plurality of chip-code signals, spread-spectrum processes the plurality of despread signals, respectively, with a chip-code-signal corresponding to a respective despread signal. For recovering a code channel using an ith chip-code-signal, subtracting circuits subtract from the spread-spectrum CDMA signal, each of the N?1 spread-spectrum-processed-despread signals thereby generating a subtracted signal. The N?1 spread-spectrum-processed-despread signals do not include the spread-spectrum-processed-despread signal of the ith channel of the spread-spectrum CDMA signal. The channel correlator or channel-matched filter despreads the subtracted signal.

Abstract: Apparatus employed by a remote unit wherein a plurality of channels are received as a received signal. Each channel is associated with a code. For each of the plurality of channels, others of the plurality of channels are subtracted from the received signal and a result of that subtracting is despread as data for that channel.

Abstract: A method employed by a remote unit wherein a plurality of channels are received as a received signal. Each channel is associated with a code. For each of the plurality of channels, others of the plurality of channels are subtracted from the received signal and a result of that subtracting is despread as data for that channel.

Abstract: Apparatus employed by a base station wherein a plurality of channels are received as a received signal. Each channel is associated with a code. For each of the plurality of channels, others of the plurality of channels are subtracted from the received signal and a result of that subtracting is despread as data for that channel.

Abstract: A method employed by a base station wherein a plurality of channels are received as a received signal. Each channel is associated with a code. For each of the plurality of channels, others of the plurality of channels are subtracted from the received signal and a result of that subtracting is despread as data for that channel.

Abstract: A code-division-multiple-access (CDMA) system employing spread-spectrum modulation. The CDMA system has a base station, and a plurality of subscriber units. The signals transmitted between the base station and subscriber unit use spread-spectrum modulation. The system and method transmits from the base station, a synchronization channel having a chip-sequence signal used by the plurality of subscriber units for synchronization. A first subscriber unit receives the synchronization channel, and determines timing from the synchronization channel. In order to initiate communications with the base station, the first subscriber unit transmits an access signal. The access signal has a plurality of power levels, which typically ramp up. The base station receives the access signal at a particular-power level. The base station then transmits to the first subscriber unit an acknowledgment signal. The first subscriber unit receives the acknowledgment signal, and transmits to the base station, a spread-spectrum signal.

Abstract: A code-division-multiple-access (CDMA) system employing spread-spectrum modulation. The CDMA system has a base station (BS), and a plurality of subscriber units (SUs). The signals transmitted between the BS and SU use spread-spectrum modulation. The apparatus for maintaining control of power from an SU to a BS, comprises sending from the SU, using spread-spectrum modulation, a SU-spreading code, and detecting at the base station, the SU-spreading code from the SU. In response to detecting the SU-spreading code at the BS, a BS-spreading code is sent to the SU, using spread-spectrum modulation. At the SU, if the BS-spreading code is detected, then transmit power of the SU is reduced. If the BS-spreading code is not detected at the SU, then transmit power of the SU is increased.

Abstract: A plurality of code division multiple access (CDMA) channel signals are received as a received signal. The received signal is despread using a code of a first channel of the plurality of CDMA channel signals to produce estimates of the first channel. The estimates of the first channel are respread using the code of the first channel. The respread estimates of the first channel are subtracted from the received signal to produce a subtracted signal. The subtracted signal is despread using a code of a second channel of the plurality of CDMA channel signals to produce estimates of the second channel.

Abstract: The admissibility of periodic traffic to a wireless medium can be estimated using a measurement report format that includes a field indicating the number of bins for a predetermined channel of the wireless medium that were busy during a measurement period, and a field indicating the number of bins for the predetermined channel of the wireless medium that were idle during the measurement period. Additionally, the measurement report format includes a field indicating the granularity in multiples of slot times of the wireless medium and a plurality of Bin Density fields, such that one Bin Density field indicates a density of medium time that the wireless medium is busy, and at least one other Bin Density field indicates a distribution of idle time after the wireless medium was busy for time 0 slots.

Abstract: A method and system for rapidly acquiring a spreading code, used in a code division multiple access (CDMA) system. A first long code and a second long code, with each long code having a length of N chips, are generated. The first long code is different from the second long code. The first long code and the second long code are transmitted at a first phase angle and at a second phase angle, respectively, on a carrier signal, over a communications channel using radio waves. The first long code and the second long code may be transmitted at an in-phase (I) angle and at a quadrature-phase (Q) angle, respectively, on the carrier signal. From the communications channel, an I-phase acquisition circuit and a Q-phase acquisition circuit may acquire, in parallel, the first long code and the second long code from the I-phase angle and the Q-phase angle, respectively, of the carrier signal by searching, in parallel, N/2 chips, the first long code and the second long code.

Abstract: A communication system includes a data transmitter and a data receiver in which the data transmitter transmits data using a multicarrier modulation, such as an OFDM modulation technique. The data receiver determines a predetermined level of modulation for at least one carrier of the multicarrier modulation corresponding to a received signal-to-noise ratio for the carrier using a vector quantization technique. The predetermined level of modulation for each carrier is based on an index to a codeword in a codebook corresponding to the signal-to-noise ratio for the carrier. The index to the codeword is a nearest neighbor to a vector corresponding to the signal-to-noise ratio for the carrier, and the codeword for each predetermined level of modulation is determined based on an adaptive-bit-loading technique. The data receiver transmits the index to the codeword for each carrier to the data transmitter in order to update the modulation at the data transmitter.

Abstract: A code-division-multiple-access (CDMA) system employing spread-spectrum modulation. The CDMA system has a base station (BS), and a plurality of subscriber units. The signals transmitted between the base station and subscriber unit use spread-spectrum modulation. The improvement method for adaptive reverse power control (APC) from a subscriber unit (SU) to a base station (BS), comprises the steps of sending from the subscriber unit, using spread-spectrum modulation, a SU-spreading code on a reverse channel. The base station despreads the SU-spreading code on the reverse channel as a despread signal, determines a first power level Pd which includes power of the despread signal plus noise and a second power level PN, which includes despread-noise power.

Abstract: A method of selectively providing MIMO transmission/reception in a WLAN system includes using a TSPEC reservation and signaling mechanism to instantiate and tear down, dynamically, multi-channel operation in a WLAN; providing an inference algorithm to determine the minimum number of channels required to establish a TSPEC using a MIMO WLAN system; providing specific channel parameters as parameters to be negotiated in the TSPEC; providing frame exchange sequences to be used in Enhanced Distributed Coordinated Access contention based access and to be used in polled access; and providing a mechanism wherein an access point makes a decision as to whether to admit MIMO functionality on a given link, wherein a “link” is a set of communications between two specific WLAN stations.

Abstract: A system and method are provided for controlling bandwidth allocation in a wireless local area network (wLAN). The method comprises: expressing device bandwidth allocations in terms of a time base; in response to expressing the bandwidth allocation in terms of a time base, monitoring network communications; and, measuring the allocated bandwidths. The method may further comprise: establishing polling schedules in response to the time-based bandwidth allocation; and, de-energizing devices in response to the polling schedules. Expressing device bandwidth allocations in terms of a time base includes establishing: an inter-transmission opportunity (TXOP) interval; and, a TXOP jitter. These fields are supplied in the IEEE 802.11e transmit specification (TSPEC). Then, de-energizing devices in response to the polling schedule includes disengaging transmission and receiving functions in the minimum TXOP intervals between polling events, where the minimum TXOP interval is the inter-TXOP interval minus the TXOP jitter.

Abstract: A method of synchronizing clocks in the stations of ad hoc and infrastructure networks includes providing a time stamp field in a header; reading the header by all stations in a network; extracting the time stamp information from the header by each station in the network as time information; sending extracted time information to a station clock; and adjusting the station clock as a function of the extracted time information. A system for synchronizing clocks in the stations of ad hoc and infrastructure networks includes a DLL having a comparator for receiving the time stamp information and a low-pass filter having a long time-constant for adjusting the station clock in a gradual manner; a time stamp field in a header; and time information extracted from the time stamp information of the header by each station in the network.

Abstract: A plurality of code division multiple access (CDMA) channel signals are received as a received signal. The received signal is despread using a code of a first channel of the plurality of CDMA channel signals to produce estimates of the first channel. The estimates of the first channel are respread using the code of the first channel. The respread estimates of the first channel are subtracted from the received signal to produce a subtracted signal. The subtracted signal is despread using a code of a second channel of the plurality of CDMA channel signals to produce estimates of the second channel.

Abstract: A code-division-multiple-access (CDMA) system employing spread-spectrum modulation. The CDMA system has a base station, and a plurality of subscriber units. The signals transmitted between the base station and subscriber unit use spread-spectrum modulation. The system and method transmits from the base station, a synchronization channel having a chip-sequence signal used by the plurality of subscriber units for synchronization. A first subscriber unit receives the synchronization channel, and determines timing from the synchronization channel. In order to initiate communications with the base station, the first subscriber unit transmits an access signal. The access signal has a plurality of power levels, which typically ramp up. The base station receives the access signal at a particular-power level. The base station then transmits to the first subscriber unit an acknowledgment signal. The first subscriber unit receives the acknowledgment signal, and transmits to the base station, a spread-spectrum signal.

Abstract: A multiple access, spread-spectrum communication system processes a plurality of information signals received by a Radio Carrier Station (RCS) over telecommunication lines for simultaneous transmission over a radio frequency (RF) channel as a code-division-multiplexed (CDM) signal to a group of Subscriber Units (SUs). The RCS receives a call request signal that corresponds to a telecommunication line information signal, and a user identification signal that identifies a user to receive the call. The RCS includes a plurality of Code Division Multiple Access (CDMA) modems, one of which provides a global pilot code signal. The modems provide message code signals synchronized to the global pilot signal. Each modem combines an information signal with a message code signal to provide a CDM processed signal. The RCS includes a system channel controller is coupled to receive a remote call.

Abstract: A spread-spectrum code division multiple access interference cancellation method employed by a remote terminal reduces interference in a direct sequence CDMA receiver having N chip-code channels. The interference canceller despreads the spread-spectrum CDMA signal as a plurality of despread signals, respectively. A timed version of the plurality of chip-code signals, spread-spectrum processes the plurality of despread signals, respectively, with a chip-code-signal corresponding to a respective despread signal. For recovering a code channel using an ith chip-code-signal, subtracting circuits subtract from the spread-spectrum CDMA signal, each of the N?1 spread-spectrum-processed-despread signals thereby generating a subtracted signal. The N?1 spread-spectrum-processed-despread signals do not include the spread-spectrum-processed-despread signal of the ith channel of the spread-spectrum CDMA signal. The channel correlator or channel-matched filter despreads the subtracted signal.