Abstract: Techniques for framing data in various data transmission contexts are described. A data framing technique may include a transmitter sending a data stream including repeating bits in alternating forward and reverse order. A receiver of the data stream may fold the data stream, and correlate portions of the folded data stream for purposes of validating the data stream and/or identifying an ID in the data stream. In at least some instances, once the receiver validates the data stream, the receiver may accept payload accompanying the data stream.

Abstract: The disclosed structures and methods are directed to polar code decoders and methods for polar code decoding. A polar code decoder comprises an input logarithmic likelihood ratio (LLR) distributor, a master polar decoder module (PDM), at least one slave PDM, an intermediate LLR result combiner, and a decoded bit aggregator configured to generate a decoded codeword bit sequence. For each codeword node, each PDM partially decodes one or more sets of LLR subsets, which are sent to the intermediate LLR result combiner to generate an intermediate LLR result sequence. A first node decoding pipeline of the master PDM is configured to decode an intermediate LLR result sequence to generate at least one decoded node bit sequence. A polar code decoder with slave PDMs each having a second node decoding pipeline is also disclosed. A method for polar code decoding is also disclosed.

Abstract: A radar system wherein a radar return is channelized by frequency into a plurality of channels, and each of the channels is sampled by a respective analog-to-digital converter that has a sampling rate less than the Nyquist rate of the radar return. The digitally sampled channel signals are Fourier transformed into the frequency domain, where each of the frequency-domain channel signals is matched-filtered according to a respective partial matched filter. The channel signals are then transformed back to the time domain, whereupon they are added together to generate the impulse response of the radar system responsive to the radar return.

Abstract: Methods and systems are provided for a protected communications architecture in which a pool of limited availability channels are shared through the transmission of encoded symbols with time-varying path diversity by a pool of users. The communications architecture can be managed by a network controller that stores availability data describing the availability of multiple-access satellite communications channels. The network controller allocates a first user to a first time-varying subset of the plurality of multiple-access satellite or terrestrial communications channels based on the availability data. The network controller updates the availability data based on the allocation of the first user. The network controller allocates a second user to a second time-varying subset of the plurality of multiple-access satellite or terrestrial communications channels based on the updated availability data.

Abstract: A communication receiving apparatus, a signal receiving method thereof, and a signal transmitting method based Code Division Multiple Access (CDMA) technology are provided. A communication transmitting apparatus encodes an original data sequence based on a perfect Gaussian integer sequence (PGIS) to generate a spread signal and transmits a radio frequency (RF) signal including the spread signal. An autocorrelation function of the PGIS conforms to an impulse characteristic, and the PGIS has a spectrum with equal magnitude. The communication receiving apparatus obtains the RF signal from the communication transmitting apparatus and transforms the RF signal into a baseband signal. The baseband signal is de-modulated into a data stream by the communication receiving apparatus. The data stream is recovered into at least one data value of the original data sequence based on the PGIS by the communication receiving apparatus.

Abstract: A method for transmitting data in series includes producing a scrambled signal by applying a scrambling using a pseudo-random sequence to an incoming serial signal conveying the data and producing an outgoing serial signal. The scrambled signal is monitored to detect occurrences of one or more data patterns. In response to the detection of one or more occurrences, one or more actions are taken to protect data in the output signal.

Abstract: Disclosed are some examples of systems, methods and storage media for generating a platform-independent document. In some implementations, a system is capable of receiving a request to generate a platform-independent document, the request including markup language content. The system is further capable of providing the markup language content to a rendering engine. The system is further capable of intercepting resource requests communicated from the rendering engine. The system is further capable of communicating the intercepted requests, or one or more requests based on the intercepted requests, to retrieve resources identified in the intercepted requests. The system is further capable of receiving resources retrieved based on the communicated intercepted requests. The system is further capable of providing the retrieved resources to the rendering engine, which subsequently renders the platform-independent document based on the markup language content and the retrieved resources.

Abstract: A sensor may encode data using a first encoding scheme. The first encoding scheme may include encoding a data bit, included in the data, using a first chip sequence that corresponds to a first set of current levels. A second encoding scheme may be used by another sensor to encode other data. The second encoding scheme may include encoding a data bit, included in the other data, using a second chip sequence that corresponds to a second set of current levels. The first chip sequence and the second chip sequence being different chip sequences. The sensor may modulate a current, based on the first set of current levels, to provide the encoded data.

Abstract: The present invention is related to location positioning systems, and more particularly, to a method and apparatus for making accuracy improvements to a GPS receiver's navigation calculations. According to a first aspect, the invention includes extreme sensitivity GNSS tracking loops. In embodiments, the tracking loops are self-bandwidth normalizing and the loop bandwidths automatically narrow with reduced CNO.

Abstract: A method for transmitting data in series includes producing a scrambled signal by applying a scrambling using a pseudo-random sequence to an incoming serial signal conveying the data and producing an outgoing serial signal from the scrambled signal. After each sequence of N consecutive bits at the same state in the scrambled signal, a dummy bit of reverse state is inserted in the outgoing signal.

Abstract: Aspects of a wireless apparatus and a method for handling a modulated signal include a frequency generator that produces a clock signal, a first synchronization circuit that generates a first sync enable signal based on an even edge of the clock signal, a second synchronization circuit that generates a second sync enable signal based on an even edge of the clock signal, a first divider having a first initial operating condition that generates a first IQ path based on the first sync enable signal, and a second divider having a second initial operating condition that generates a second IQ path based on the second sync enable signal, wherein the first and second operating conditions are not equal when initially powered.

Abstract: To facilitate multi-channel communications over distributed-control radio networks, the timing of networks on multiple substantially independent channels are adjusted (350) so as to establish a common time base among the networks. With this common time base, data is transmitted concurrently (230), using the bandwidth provided by the multiple networks. To further optimize the efficiency of this technique for cognitive radio networks, the quiet period (QP) and signaling window (SW) on each network are scheduled (355) to provide overlapping quiet periods (QP) and/or overlapping signaling windows (SW). Preferably, each multi-channel user is assigned (360) the same time slot in the beacon periods (210) of the network on each channel, thereby facilitating efficient beacon transmission and reception.

Abstract: A transmission apparatus includes a plurality of orthogonal frequency division multiplexing (OFDM) modulation signal generators, which generate a first OFDM modulation signal and a second OFDM modulation signal. The transmission apparatus also includes a transmitter that transmits the first OFDM modulation signal from a first antenna and the second OFDM modulation signal from a second antenna, in an identical frequency band.

Abstract: A wireless communications method is provided. The method includes employing a processor executing computer executable instructions stored on a computer readable storage medium to implement various acts. The method also includes generating cyclic shifts for a sequence generator by masking shift register output values with one or more vectors. The method includes forwarding the sequence generator to a future state based in part on the output values and the vectors.

Abstract: Embodiments disclosed herein relate to apparatus and methods of transceiver power noise reduction. One embodiment relates to a method of serial data communication. At a transmitter, data may be encoded by a communication protocol encoder, and the protocol-encoded data may be serialized. The serialized data may be encoded for power-delivery-network noise reduction (PNR) so as to generate PNR-encoded serial data, and the PNR-encoded serial data may be driven onto a communication channel. Other embodiments, aspects, and features are also disclosed.

Abstract: An approach is provided for correlation of a signal over time and frequency. The signal is correlated with a bit sequence over time instances and certain frequency offsets, wherein sub-segments of the signal are correlated with sub-segments of the bit sequence to generate a correlation factor associated with each signal sub-segment. The correlation factors are coherently combined to generate a final correlation factor, wherein a respective phase shift (for each frequency offset) is applied to each correlation factor to generate a set of frequency adjusted correlation factors, and the frequency adjusted correlation factors of a respective set are combined to generate the final correlation factor over the signal sub-segments, resulting in the matrix of final correlation factors over time and frequency. A signal parameter estimation is performed, based on the matrix of final correlation factors, to determine a highest correlation value for the signal over the frequency offsets.

Abstract: A timing source is provided for sending timing information via a packet network. The source comprises a first clock for generating the timing information and a packet forming section for forming a sequence of packets. An output section in the form of a packet launch control section transmits the packets via the network as packet bursts, each of which comprises a plurality of packets with the intervals between consecutive packets of each burst being less than the intervals between consecutive packets. A time-stamping section inserts into each packet a transmission time derived from the timing information generated by the clock.

Abstract: A method of synchronizing a time division duplex (TDD) multi-line, multi-carrier data communication system is provided. Synchronization is established using unique pseudo-random bit sequences (PRBS) from a common generator polynomial having different seed values. Due to low correlation of PRBS generated with different seed values, a remote unit can only synchronize to its intended signal effectively mitigating far-end and near-end crosstalk impact of large bandwidth very high speed digital subscriber lines (VDSL).

Abstract: A method of hitless switching over a communications link, the method comprising transmitting, by a first modulator to a remote receiver, a first carrier signal having a first center frequency, enabling, by a second modulator to the remote receiver, transmission of a second carrier signal having a second center frequency while the first modulator is transmitting the first carrier signal, increasing, through the second modulator, a power level of the second carrier signal while the first carrier signal is transmitting, simultaneously decreasing, through the first modulator, a power level of the first carrier signal while the power level of the second carrier signal is increasing, and disabling transmission of the first carrier signal to the remote receiver when the power level of the second carrier signal reaches a predetermined level.

Abstract: Ethernet network link partners may be configured for operation in a low power mode. The link partners may generate new frames and/or signals and/or may modify characteristics of existing frames and/or signals to be communicated via one or more channels of an Ethernet link during the low power mode. The new and/or modified frames and/or signals may be utilized as refresh frames and/or signals to control communication during low power mode and/or to enable refresh and/or synchronization of the link partners. The new and/or modified frames and/or signals may be generated and/or modified based on a desired frequency distribution and/or spectral density. New and/or modified frames and/or signals may comprise jitter, random and/or pseudo random bit patterns and/or varied bit patterns and/or energy levels. Data packets and/or active idle symbols may be forced during low power mode to mitigate undesired periodic energy.

Abstract: Provided is an apparatus and method for analyzing identification (ID) signals by converting radio frequency (RF) signals which are transmitted with an ID signal added thereto by a transmitting part, e.g., a plurality of transmitters or repeaters, into signals of a desired band; creating ID signals that are identical to the ID signals added to the RF signals; calculating correlation values between the converted signals and the created ID signals based on partial correlation; and extracting channel profile of multi-path signals caused by a channel between the transmitting part and the ID signal analyzing apparatus from the correlation value. The technology of the present research is applied to broadcasting and communication.

Abstract: An arrangement for providing synchronization between a number of overlapping area access points within a wireless LAN utilizes an Ethernet cable connection to transmit synchronization signals from a centralized hub/switch to each of the access points connected to the cable. The synchronization signal takes the form of a direct sequence spread spectrum (DS-SS) signal. At each access point, a filter is used to recover the synchronization signal, allowing for the group of access points to share a common beacon signal and allowing frequency re-use among the access points.

Abstract: Systems and techniques relating to wireless communications are described. A described technique includes receiving information that is indicative of a wireless communication signal transmitted by a wireless communication device, the wireless communication signal having been generated based on a spreading sequence and a known preamble; determining, based on the received information and the known preamble, an estimation of a first frequency offset using two or more locations for encoding elements associated with the spreading sequence; determining, based on the received information, the known preamble, and the first frequency offset, an estimation of a second frequency offset using two or more locations for symbols associated with the known preamble, the second frequency offset being different from the first frequency offset; and processing the received information based on a combination of the first frequency offset and the second frequency offset.

Abstract: The present invention provides a method for range extension is wireless communication systems. One embodiment of the method includes determining whether a mobile unit is within a first range corresponding to a range of timing advances supported by a timing advance command. This embodiment also includes transmitting a plurality of timing advance commands to the mobile unit when the mobile unit is outside the first range so that the mobile unit can synchronize with the base station by combining information in the plurality of timing advance commands.

Abstract: A system including a demodulation module, a metric generation module, and a preamble detection module. The demodulation module is configured to generate demodulated signals based on demodulating, in accordance with a differential demodulation scheme, signals received from a base station. The signals received from the base station include a plurality of symbols. The demodulated signals comprise a plurality of real parts each having a corresponding magnitude. The metric generation module is configured to generate a plurality of metrics for the plurality of symbols based on the corresponding magnitudes of the plurality of real parts of the demodulated signals. The preamble detection module is configured to detect, based on the plurality of metrics, whether the plurality of symbols in the signals received from the base station includes a preamble symbol.

Abstract: A transmission apparatus includes a plurality of orthogonal frequency division multiplexing (OFDM) modulation signal generators, which generate a first OFDM modulation signal and a second OFDM modulation signal. The transmission apparatus also includes a transmitter that transmits the first OFDM modulation signal from a first antenna and the second OFDM modulation signal from a second antenna, in an identical frequency band.

Abstract: A synchronization method for impulse system ultra-wideband takes frame as basic unit for data transmission, each frame is divided into a preamble symbol part and a data part, wherein the preamble symbol part sends a known impulse sequence for channel estimation and synchronization; the data part takes the information to be transmitted; the preamble symbol part is divided into two parts of a positive and negative impulse sequence, which includes odd impulses with alternant positive and negative polarities, and a same direction impulse sequence, which is composed of impulses with same polarity and is the same as the polarity of the last impulse in the positive and negative impulse sequence. The method provides such advantages as high synchronization precision, small storage space, and capability of immediately finding out the synchronization position etc., and provides an important value for the development of the impulse system ultra-wideband wireless communication technique.

Abstract: A radio communication apparatus that performs radio communication with another communication apparatus includes an antenna unit, a contact detecting unit that detects contact with the another communication apparatus, a first modulating and demodulating unit for performing communication in a state in which the radio communication apparatus is remote from the another communication apparatus, a second modulating and demodulating unit for performing communication in a state in which the radio communication apparatus is in contact with the another communication apparatus, and a control unit that performs control to perform radio communication with the another communication apparatus via the antenna unit by selecting the first modulating and demodulating unit while the contact detecting does not detect contact with the another communication apparatus and selecting the second modulating and demodulating unit when the contact detecting unit detects contact with the another communication apparatus.

Abstract: Methods and apparatus for solving problems caused by backoff procedures like that specified in the BLUETOOTH Link Layer Specification, by introducing selected randomizations of communication channels used for communication by scanning devices.

Abstract: An arrangement for providing synchronization between a number of overlapping area access points within a wireless LAN utilizes a Power over Ethernet (PoE) cable connection to transmit synchronization signals from a centralized hub/switch to each of the access points connected to the cable. The synchronization signal takes the form of a direct sequence spread spectrum (DS-SS) signal that is coupled onto the twisted pair used to provide the low voltage PoE signal to various powered devices. At each access point, a filter is used to remove the synchronization signal from the PoE transport, allowing for the group of access points to share a common beacon signal and allow for frequency re-use among the access points. The DS-SS signal is preferable created by a combination of a baseband signal and a set of separate pseudo noise (PN) sequences defining a precision phase (“pilot tone”) signal, a time mark (superframe/beacon) signal, and a time-of-day (real-time clock) signal.

Abstract: An adaptive multi-channel architecture for a wireless network is provided. A frequency hopping sequence generator module is compliant with a frequency hopping spread spectrum (FHSS) communications protocol. The frequency hopping sequence generator module is capable of performing FHSS concurrently on a plurality of communications channels. A frequency replacement module is coupled to the frequency hopping sequence generator module. The frequency replacement module is configured to receive feedback data over a feedback channel and adaptively select a transmission channel from the plurality of communications channels using the feedback data.

Abstract: A transmission apparatus includes a plurality of orthogonal frequency division multiplexing (OFDM) modulation signal generators, which generate a first OFDM modulation signal and a second OFDM modulation signal. The transmission apparatus also includes a transmitter that transmits the first OFDM modulation signal from a first antenna and the second OFDM modulation signal from a second antenna, in an identical frequency band.

Abstract: A system including multiple nodes performing radio communication, wherein each node stores routing information, uses it to determine a transmission path, and performs cut-through transmission by transmitting and receiving packets to and from a node on the determined path through transmission and reception radio waves given a directivity by controlling their phases. In the system, time synchronization and transmission and reception of packet communication records are performed during a certain time period by carrying out the cut-through transmission while controlling phases of the radio waves so that all of the nodes form one or more closed loops. The node transmits and receives packets in accordance with routing information and a time frame assigned to each of the nodes as a time when each node is allowed to transmit and receive a packet, updates the routing information, and shares it with each node.

Abstract: There is described a method for transmitting synchronization messages, for example PTP messages of the IEEE 1588 standard, the PTP message being inserted into a data packet in line with the Internet Protocol, the data packet having an IP header, and the data packet having a UDP header. In this case, for the encrypted transmission on the PTP message, the data packet is addressed to a UDP port that is reserved for encrypted PTP messages, the data packet is provided with an additional S-PTP header that is provided for encryption, the PTP message is extended with a pseudo random number, and the PTP message is encrypted together with the pseudo random number.

Abstract: A pseudo noise code (PN code) tracking circuit includes a first correlator, a storage device, a second correlator and a detector. The first correlator is utilized for performing correlation on a first PN code in a first signal frame with a local PN code to generate a first set of correlation values, and for performing correlation on a second PN code in a second signal frame with the local PN code to generate a second set of correlation values. The storage device is coupled to the first correlator for storing the first and second sets of correlation values. The second correlator is coupled to the storage device for performing correlation on the first set of correlation values with the second set of correlation values to generate a shift value. The detector is coupled to the second correlator for generating a frame number according to the shift value.

Abstract: Systems and techniques are disclosed wherein a gated pilot signal can be re-acquired faster by searching a last known pilot offset and/or searching a last coset in which the last pilot signal was found.

Abstract: A transmission signal processing method is provided, for generating a first OFDM modulation signal and a second OFDM modulation signal which are transmitted in an identical frequency band, by utilizing a first antenna for transmitting the first OFDM modulation signal and by utilizing a second antenna for transmitting the second OFDM modulation signal. The method includes a step of generating the first OFDM modulation signal and the second OFDM modulation signal utilizing a plurality of OFDM modulation signal generators, and a step of outputting the first OFDM modulation signal to the first antenna and the second OFDM modulation signal to the second antenna.

Abstract: Described is an apparatus for suppressing spurious spectral lines in a frame based bit-serial data stream, in which frames include payload data and frame markers. The apparatus includes means (16) for randomizing first frame marker elements (START) in a first position within each frame and means (18) for correlating second frame marker elements (STOP) in a second position within each frame with the randomized first frame marker element.

Abstract: Methods and systems for slow associated control channel signaling are disclosed. An example method for securing communications in a mobile network disclosed herein comprises transmitting a first variant of a message of a first type on a first slow associated control channel (SACCH) before ciphering is started on the first SACCH, and after ciphering is started on the first SACCH, transmitting a second variant of the message of the first type on the first SACCH, and subsequently transmitting the second variant of the message of the first type on the first SACCH, wherein the subsequently transmitted second variant of the message of the first type is the next transmitted message of the first type on the first SACCH.

Abstract: A system including a magnitude measuring module, an energy normalization module, and a metric generation module. The magnitude measuring module is configured to measure magnitudes of real portions of differentially demodulated signals, wherein the differentially demodulated signals are generated by differential demodulation of signals received from a base station. The energy normalization module is configured to generate a sum of energies of a plurality of subcarriers included in the signals received from the base station. The metric generation module is configured to generate a plurality of metrics for a plurality of symbols included in the signals received from the base station. The metric generation module is further configured to detect, based on the plurality of metrics, a preamble symbol included in the signals received from the base station.

Abstract: The present invention provides a method of early starting the operation of a descrambler. The method comprises the steps of receiving a, synchronous byte of a transport packet in a group of m packets, where m is an integer, generating an alignment index to indicate a location of the synchronous byte, delivering the alignment index to the descrambler, and loading an initialization sequence to the descrambler in accordance with the alignment index and starting an operation of the descrambler.

Abstract: Apparatus and methods for estimating transmission noise in a programming information signal. Channel noise power in binary phase shift keying (“BPSK”) modulated telecommunication may be estimated. Such a method may include receiving over the channel a reference signal and a data BPSK signal. The data BPSK signal may include the programming information. The method may include formulating a channel transfer function estimate for the channel based on the reference signal. The estimate may include a channel estimation error. The data BPSK signal may be equalized using the transfer function estimate. The data BPSK signal may include noise, which may be quantified in terms of power. The data BPSK signal noise power may be estimated in such a manner that is independent of the channel estimation error.

Abstract: A method (and operation of a computer program and an apparatus) includes receiving a signal over a wireless channel; correlating the received signal with a reference sequence and providing a correlation output; processing the correlation output to detect a presence of a first predetermined preamble sequence using a main correlation peak and two first order frequency shift peaks and nulling second and higher order frequency shift peaks from the correlation output prior to further processing the correlation output to detect a presence of a second predetermined preamble sequence.

Abstract: A multipath discriminator module and related methods are provided for communications and/or navigation systems that implement spread spectrum modulation. In one example embodiment, the module includes an input suitable for receiving navigation signals, a sampler for supplying sampled signals at a frequency twice the apparent frequency of the code of the signals, and a submodule for calculating an error signal from the sampled signals.

Abstract: The invention provides a code modification circuit for receiving a descrambling/dispreading code at a first input pair thereof and a pilot derotation code at a second input pair thereof, and arranged to combine the codes to form a combined code for providing to a correlator such that the correlator can recover data or a pilot signal from an input sequence supplied thereto.

Abstract: A receiver in an impulse wireless communication. The receiver (300) includes a pulse-pair correlator (304) that receives a signal (316) and divides it into two signals for paths. One of the signals is input to signal multiplier (312) while another signal is delayed by a delay unit (310). The signal multiplier (312) multiplies the received signal (316) by a delayed signal (318). An integrator (314) integrates an output signal (322) over a designated period of time. An adding module (306) sums an output signal (324) from the integrator (314). An acquiring module (308) compares an summing-up output (326) from the adding module (306) with a predetermined threshold value to detect the existence of a transmitting-standard preamble.

Abstract: A system includes an input, a differential demodulation module, a magnitude measuring module, a summing module, and a metric generator module. The input receives input signals that include s sets of modulated sub-carriers carrying symbols, where s is an integer greater than or equal to 1. The differential demodulation module generates differentially demodulated signals based on the input signals. The magnitude measuring module measures magnitudes of real portions of the differentially demodulated signals. The summing module generates s sums, wherein each of the s sums is a sum of the magnitudes generated based on a respective one of the s sets. The metric generator module generates metrics for the symbols based on the s sums.

Abstract: Methods and apparatus for reduction of a peak to average ratio for an OFDM transmit signal. In an aspect, a method is provided for reducing a peak to average ratio of a transmit waveform. The method includes obtaining a primary scrambler sequence, generating a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining the primary and secondary scrambler sequences to produce a PAR reduction sequence. In another aspect, an apparatus is provided for reducing a peak to average ratio of a transmit waveform. The apparatus includes a secondary generator configured to generate a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining logic configured to combine a primary scrambler sequence and the secondary scrambler sequences to produce a PAR reduction sequence.

Abstract: Systems and methods for avoiding non-linear behavior of conventional early-minus-late correlator-based code loop discriminators. The present invention provides a model of correlator behavior that takes into account whether both correlators are on the same side of the correlation peak or they straddle the peak. The result is a piecewise solution that can be stitched together quite readily to produce an extended range of linear response, thereby improving the pull-in capability of GPS code loops when closely spaced correlators are being used.

Abstract: The present invention discloses a method and apparatus for implementing matched filter in a system using QPSK modulation. In the present invention, a multiplier is changed as a multiplexer by using the characteristic of the pilot sequence (or training sequence) so as to implement the matched filter.