Abstract: A system and method for cognitive communication device operation. In accordance with the system and method, a node (102, 106, 107) that communicates in a wireless multihopping communication network (100) uses a receiver (302, 402, 502, 602) to acquire a digital sample of a communication signal, and extracts at least one feature of the digital sample. The node (102, 106, 107) employs a classifier (306, 406, 506) to determine the signal type, and a transmitter (108) to send feature vectors including information representing the signal type to other nodes (102, 106, 107) in the network (100).

Abstract: A system and method for routing packets in a multihopping wireless communication network (100). The system and method selects a node (106-1) of the wireless network (100) to operate as an aggregation point, at which two or more possible routes for transmitting packets or packet fragments from a source mobile node (102-1) to a destination mobile node (102-2) meet. A primary route is selected based on historical quality of one or more links between nodes (102, 106, 107), and one or more secondary routes are selected based on the success rate of packets reaching the aggregation point.

Abstract: A system and method for achieving crest factor (CF) reduction for multi-carrier modulation in a wireless communication network (100), such as an ad-hoc peer-to-peer multi-hopping mobile wireless communication network (100). The system and method use the properties of the Inverse Fourier Transform (TFT) for achieving crest-factor reduction. Specifically, the system and method map original signal input frequencies to a new set of frequencies by mapping every input frequency to some other input frequency, and then using the IFT to create multiple versions of the transmitted signal and then computing the transform with the lowest CF and selecting that signal for transmission.

Abstract: A method for measuring the time of arrival of radio signals within a network comprises receiving the received signals including at least a first pseudorandom code and a second pseudorandom code from at least one other node; identifying a frequency difference between the node and the other node using a phase difference between each of a maximum value of a cross-correlation provided by the first pseudorandom code and the second pseudorandom code; applying the frequency difference to the reception of the received signal; and calculating the time of arrival of the received signal comprising a time, measured with a local clock, when the cross-correlation has achieved the maximum value.

Abstract: A system and method for controlling the quantity of training symbols in a transmission sequence sent by a terminal (102, 106, 107) in a wireless network (100). The transmission sequence include training symbols and data symbols. The system and method determine the number of data symbol errors which are close to training symbols in the transmission sequence, determine the number of symbol data errors which are far from training symbols in the transmission sequence, and adjust the quantity of training symbols in the transmission sequence based on a result of a comparison of the ratio of the number of data symbol errors which are close to training symbols to the number of data symbol errors which are far from training symbols.

Abstract: A method of operation of a communication device. A first communication module is operatively coupled to a second communication module within the communication device. The second communication module is designed for carrier sensing. An instruction is communicated from the first communication module to the second communication module to begin sensing a channel on behalf of the first communication module. Next, the first communication module is informed of channel activity status by the second communication module. Thereafter, the first communication module transmits on the channel when no activity is detected on the channel.

Abstract: An apparatus for use with a shared access communication channel is disclosed. The chipping rate of a first group of terminals is determined. Transmissions on the shared access communication channel are encoded using first pseudorandom noise (PN) code and a phase shift at the first chipping rate and an orthogonal spreading code having a chipping rate less than the first chipping rate. The apparatus may receive a feedback channel assignment and may receive an indication of a change in timing on the assigned feedback channel.

Abstract: A first time division multiplex (TDM) time slot is provided which is defined as a bi-directional channel for use in a TDM network including a source node and a destination node. The source node can transmit data to the destination node in a first portion of a first TDM time slot. In one implementation, a second portion of the same first TDM time slot can be reserved for the destination node to transmit information to the source node. The destination node can determine whether the data from the source node has arrived properly, and then transmit an indication message to the source node in the second portion of the same first TDM time slot to indicate whether the data from the source node has arrived properly at the destination node.

Abstract: A technique for allowing a first and second group of users to share access to a communication channel such as a wireless radio channel is disclosed. The first group of users can be a group of legacy users such as those that use digital CDMA cellular telephone equipment based on the IS-95 standard. The second group of users can be a group of web surfers that code their transmissions using one of multiple formats. The first group of users can share one modulation structure such as, on a reverse link, using unique phase offsets of a common pseudorandom noise (PN) code. The second group of users can share another modulation structure, but in a manner that is consistent and compatible with the users of the first group. Specifically, the users of the second group may all use the same PN code and code phase offset. Each channel used by the second group of users can be uniquely identified by a corresponding unique orthogonal code.

Abstract: A method and system for measuring the time-of-flight (TOF) of a radio signal is described herein. According to various implementations, the system uses multiple antennas, each of which receives direct path radio signals and reflected radio signals. In various implementations, the system sends a sequence of bursts that are detected using a cross correlation detector. The receiver steers antenna nulls to a different angles for each burst and measures the TOF at each angle. The system then calculates the minimum correlation peak from all measurements, and treats that correlation peak as the true, direct path TOF measurement.

Abstract: The present invention provides a bandwidth efficient system and method of measuring the range between nodes (102, 106, 107) in a wireless communications network (100) with one-way data transfer, where each node (102, 106, 107) periodically transmits a message that contains information regarding neighboring nodes (102, 106, 107) from which any prior messages have been received by the transmitting node (102, 106, 107). A node (102, 106, 107) receives the messages transmitted from neighboring nodes (102, 106, 107) in the network (100), and records the times of arrival of the received messages. The node (102, 106, 107) receiving those messages can thus determine the respective distances between itself and the neighboring nodes (102, 106, 107) based on the respective time of arrivals of the received messages and the respective information included in the respective messages.

Abstract: A method for measuring the Time Of Arrival of signals in a communications network is provided. A transmitter emits a beacon that is a digital message of known content, followed by timing information. The message is preceded by a pseudo-random binary phase-shift keying (BPSK) modulated sequence that allows the receiver to synchronize on the received signal using the autocorrelation method. During the synchronization process, are computed the approximated Time Of Arrival (TOA) and approximated frequency difference between the local oscillator and the received signal. The content of the beacon message is then used for correcting the approximated TOA and the frequency differences, providing results of very high precision of TOA. The timing information that follows the beacon is used for network clock synchronization and for computing the distances between network nodes.

Abstract: A system and method for creating a spectrum agile wireless multi-hopping network, such as a wireless ad-hoc peer-to-peer multi-hopping network. The spectrum agile multi-hopping network that can respond to conditions affecting spectrum, such as FCC rulings or business related agreements on spectrum licensing related to a location or other measurable parameters of the network.

Abstract: A system and method including an algorithm that can use the linear time shift property of the subcarrier modulation to provide accurate frame synchronization for communications between nodes in a wireless network, where nodes employ orthogonal frequency division multiplexing (OFDM) modems. The subcarrier modulation is typically performed with a Fast Fourier Transform (FFT) that includes a time shift between Inverse Fast Fourier Transform (IFFT) and guard interval insertion at transmission, but due to the guard insertion, the system and method of the present invention corrects the time shifts allowing accurate TOF calculations.

Abstract: A system and method for transmitting data in a wireless network is provided. Routing table information includes a system weight associated with each available node. An optimal node is selected based at least in part on the system weight, quality of service requirements, among other factors associated with each available node. Nodes are preferably selected on a per packet basis.

Abstract: A technique for allowing a first and second group of users to share access to a communication channel such as a radio channel. A first group of users is typically a legacy group of users such as those using digital CDMA cellular telephone equipment. The second group of users are a group of data users that code their transmissions in different formats optimized for data functionalities. The first group of users share one modulation structure such as, on a reverse link, using unique phase offsets of a common pseudorandom noise (PN) code. The second group of users share another modulation structure but in a manner that is consistent and compatible with the users of the first group. Specifically, the users of the second group may all use the same PN code and code phase offset. However, they are uniquely identified such as, for example, assigning each of them a unique orthogonal code.

Abstract: A system and method for providing optimum wireless communication spreading code selection such that communication channel interpath interference is minimized. In Direct-Sequence Spread-Spectrum, the autocorrelation properties of a spreading code greatly affects the inherent ability of a system to resist multipath. Low/spreading gain codes (or “short” codes) associated with high data rates do not perform well where large-amplitude multipath is present. The system and method presented herein overcomes this problem by selecting spreading codes in such a way that interference caused by multipath is minimized. The system and method does so by determining the characteristics of the radio-frequency link in order to select a spreading code that will minimize interpath interference.

Abstract: A technique for allowing a first and second group of users to share access to a communication channel such as a wireless radio channel is disclosed. The first group of users can be a group of legacy users such as those that use digital CDMA cellular telephone equipment based on the IS-95 standard. The second group of users can be a group of web surfers that code their transmissions using one of multiple formats. The first group of users can share one modulation structure such as, on a reverse link, using unique phase offsets of a common pseudorandom noise (PN) code. The second group of users can share another modulation structure, but in a manner that is consistent and compatible with the users of the first group. Specifically, the users of the second group may all use the same PN code and code phase offset. Each channel used by the second group of users can be uniquely identified by a corresponding unique orthogonal code.

Abstract: A system and method including an algorithm that can use the linear time shift property of the subcarrier modulation to provide accurate frame synchronization for communications between nodes in a wireless network, where nodes employ orthogonal frequency division multiplexing (OFDM) modems. The subcarrier modulation is typically performed with a Fast Fourier Transform (FFT) that includes a time shift between Inverse Fast Fourier Transform (IFFT) and guard interval insertion at transmission, but due to the guard insertion, the system and method of the present invention corrects the time shifts allowing accurate TOF calculations.

Abstract: Method and apparatus for base stations and subscriber units allows soft handoff of a CDMA reverse link utilizing an orthogonal channel structure. Subscriber units transmit an orthogonally coded signal over a reverse link to the base stations. A given base station provides timing control of the timing offset of the reverse link signal. Based on at least one criterion, an alignment controller determines that the given base station should hand off timing control to another base station, and a soft handoff process ensues. In response to a command or message for soft handoff of the subscriber unit from the given base station to another base station, the subscriber unit makes a coarse timing adjustment to the timing of the coded signal. The subscriber unit may make fine timing adjustments based on feedback from the base station controlling timing. Multiple base stations may provide power control feedback to the subscriber unit.