5439 results about "Band width" patented technology

Carrier Interferometry (CI) provides wideband transmission protocols with frequency-band selectivity to improve interference rejection, reduce multipath fading, and enable operation across non-continuous frequency bands. Direct-sequence protocols, such as DS-CDMA, are provided with CI to greatly improve performance and reduce transceiver complexity. CI introduces families of orthogonal polyphase codes that can be used for channel coding, spreading, and/or multiple access. Unlike conventional DS-CDMA, CI coding is not necessary for energy spreading because a set of CI carriers has an inherently wide aggregate bandwidth. Instead, CI codes are used for channelization, energy smoothing in the frequency domain, and interference suppression. CI-based ultra-wideband protocols are implemented via frequency-domain processing to reduce synchronization problems, transceiver complexity, and poor multipath performance of conventional ultra-wideband systems. CI allows wideband protocols to be implemented with space-frequency processing and other array-processing techniques to provide either or both diversity combining and sub-space processing. CI also enables spatial processing without antenna arrays. Even the bandwidth efficiency of multicarrier protocols is greatly enhanced with CI. CI-based wavelets avoid time and frequency resolution trade-offs associated with conventional wavelet processing. CI-based Fourier transforms eliminate all multiplications, which greatly simplifies multi-frequency processing. The quantum-wave principles of CI improve all types of baseband and radio processing.

This disclosure demonstrates a new class of Ultra-Wide Band (UWB) AMC with very large fractional bandwidth (>100%) even at lower frequencies (<1 GHz). This new UWB AMC is enabled by recognizing that any AMC must be an antenna in order to accept the incident radiation into the circuit. Therefore, by using UWB antenna design features, one can make wide band AMCs. Additionally, by manipulation of the UWB AMC element design, a 1/frequency dependence can be obtained for instantiating the benefits of a quarter wave reflection over a large UWB bandwidth with a single physical thickness.

The present invention provides a new class of hybrid-mode horn antennas. The present invention facilitates the design of boundary conditions between soft and hard, supporting modes under balanced hybrid condition with uniform as well as tapered aperture distribution. In one embodiment, the horn antenna (100) is relatively simple mechanically, has a reasonably large bandwidth, supports linear as well as circular polarization, and is designed for a wide range of aperture sizes.

The present invention describes a novel methodology for adjusting a bandwidth extension algorithm by adapting one or more of enhancing perception parameters (e.g., a signal level, a signal energy and/or a gain) of a high-band encoded signal based on the characteristics of the input signal and an encoding performance in a low band with a codec utilizing audio-band-split coding by separate encoders and decoders for each audio band. The adaptation is based on the low-band coding algorithm. It can be at least two types of such an algorithm: e.g., an algebraic code excitation linear prediction (ACELP) algorithm for a speech-like input signal and a transform algorithm of a non-speech-like input signal, such that when the ACELP coding is selected, the corresponding enhancing perception parameter is gradually tuned down and when the encoding algorithm is changed to the transform coding, the corresponding enhancing perception parameter is gradually tuned up.

A bus permits the number of active serial data lanes of a data link to be re-negotiated in response to changes in bus bandwidth requirements. In one embodiment, one of the bus interfaces triggers a re-negotiation of link width and places a constraint on link width during the re-negotiation.

A first aspect of the present invention relates to a method for low-frequency emphasizing the spectrum of a sound signal transformed in a frequency domain and comprising transform coefficients grouped in a number of blocks, in which a maximum energy for one block is calculated and a position index of the block with maximum energy is determined, a factor is calculated for each block having a position index smaller than the position index of the block with maximum energy the calculated maximum energy and the energy of the block, and, for each block, a gain determining from the factor is applied to the transform coefficients of the block. Another aspect of the invention is concerned with an HF coding method for coding, through a bandwidth extension scheme, an HF signal obtained from separation of a full-bandwidth sound signal into the HF signal and a LF signal, in which an estimation of the an HF gain is calculated from LPC coefficients, the energy of the HF signal is calculated, the LF signal is processed to produce a synthesized version of the HF signal, the energy of the synthesized version of the HF signal is calculated, a ratio between the energy of the HF signal and the energy of the synthesized version of the HF signal is calculated and expressing as an HF gain, and a difference between the estimation of the HF gain and the HF gain is calculated to obtain a gain correction. A third aspect of the invention is concerned with a method for producing from a decoded target signal an overlap-add target signal in a current frame coded according to a first coding mode. According to this method, the decoded target signal of the current frame is windowed and a left portion of the window is skipped. A zero-input response of a weighting filter of the previous frame coded according to a second coding mode is calculated and windowed so that the zero-input response has an amplitude monotonically decreasing to zero after a predetermined time period. Finally, the calculated zero-input response is added to the decoded target signal to reconstruct the overlap-add target signal.

To reduce bandwidth of non-scalable MPEG-2 coded video, certain non-zero AC DCT coefficients for the 8x8 blocks are removed from the MPEG-2 coded video. In one implementation, high-frequency AC DCT coefficients are removed at the end of the coefficient scan order. This method requires the least computation and is most desirable if the reduced-bandwidth video is to be spatially sub-sampled. In another implementation, the smallest-magnitude AC DCT coefficients are removed. This method may produce an undesirable increase in the frequency of occurrence of escape sequences in the (run, level) coding. This frequency can be reduced by retaining certain non-zero AC DCT coefficients that are not the largest magnitude coefficients, and by increasing a quantization scale to reduce the coefficient levels. The reduced-bandwidth video can be used for a variety of applications, such as browsing for search and play-list generation, bit stream scaling for splicing, and bit-rate adjustment for services with limited resources and for multiplexing of transport streams.

A data chunking system divides data into predominantly fixed-sized chunks such that duplicate data may be identified. The data chunking system may be used to reduce the data storage and save network bandwidth by allowing storage or transmission of primarily unique data chunks. The system may also be used to increase reliability in data storage and network transmission, by allowing an error affecting a data chunk to be repaired with an identified duplicate chunk. The data chunking system chunks data by selecting a chunk of fixed size, then moving a window along the data until a match to existing data is found. As the window moves across the data, unique chunks predominantly of fixed size are formed in the data passed over. Several embodiments provide alternate methods of determining whether a selected chunk matches existing data and methods by which the window is moved through the data. To locate duplicate data, the data chunking system remembers data by computing a mathematical function of a data chunk and inserting the computed value into a hash table.

An exemplary embodiment includes partitioning a data message to be communicated from a first data site to a second data site into data chunks; generating a data chunk identifier for each data chunk; determining whether the data chunks are stored at the second data site; when at least one data chunk is not stored at the second data site, adding the data chunk identifier for each data chunk not stored at the second data site to a data structure at the first data site; sending a transformed data message from the first date site to the second data site; wherein, when at least one data chunk is already stored at the second data site, rather than including that data chunk, the transformed data message instead includes at least one tuple to enable the data message to be reconstructed at the second data site without sending the previously stored data chunk, the transformed data message also includes each data chunk not stored at the second data site.

The present invention is related to methods and apparatus that compensate for quadrature impairments of an analog quadrature modulator and/or demodulator over a relatively wide signal bandwidth. One embodiment pre-distorts baseband signals in a quadrature modulator compensation signal processor (QMCSP) to negate the quadrature impairment of an analog quadrature modulator and corrects a received baseband signal in a quadrature demodulator compensation signal processor (QDCSP) to cancel the quadrature impairment of an analog quadrature demodulator. The QMCSP and the QDCSP contain adaptive digital filter correction structures that pre-compensate and post-compensate, respectively, for the quadrature impairments introduced by the analog quadrature modulator and the analog quadrature demodulator over a relatively wide bandwidth. A phase shifter advantageously shifts the phase of a local oscillator signal to the analog quadrature demodulator to distinguish quadrature impairments introduced by the modulation path from quadrature impairments introduced by the demodulation path.

A class of bandwidth reduction techniques are used develop a broad class of modulation types collectively called SSB-FM. These signals can be used to construct communication systems that provide bandwidth-normalized performance gains of 10 dB or more when compared to popular prior art modulation methods. An aspect of the invention involves mapping trellis paths in a complex signal space onto corresponding real-valued trellis signals with desirable spectral properties. The invention can be used map continuous phase modulated (CPM) signals onto simpler amplitude-modulated trellis signals having double the channel capacity of prior art CPM signals. Multi-amplitude signaling and frequency division multiplexing may also be incorporated to further accommodate more information per symbol.

An arbitrary waveform generator (AWG) for producing an analog output current signal includes a random access memory (RAM), a programmable logic device (PLD), a programmable pattern generator, several digital-to analog converters (DACS) and a current multiplexer. The RAM store data sequences representing the analog waveform to be generated. The pattern generator read addresses the RAM causing it to sequentially read out its stored data sequence to the PLD. The PLD routes selected fields of each data sequence word to one or more of the DACs in response to timing signals provided by the pattern generator. Each DAC produces an output current of magnitude determined by its input waveform and range data. The pattern generator also signals the analog multiplexer to sum currents produced by one or more selected DACs to produce the AWG output waveform. The nature of the AWG output waveform is flexibly determined by the nature of the data sequence and the frequency at which it is read out of the RAM, the manner in which the PLD routes the data sequence to the DACs, the value of the range data supplied to each DAC, and the output pattern generated by the pattern generator. The flexible AWG architecture permits the AWG to be appropriately configured for various combinations of output waveform frequency, bandwidth and resolution requirements.

Systems and/or methods for supporting communications at a reduced bandwidth with a full bandwidth network such as a long-term evolution (LTE) network may be disclosed. For example, inband assignments such as downlink assignments and/or uplink grants may be provided and/or received and transmissions may be monitored and/or decoded based on the inband assignment. Additionally, information (e.g. a definition or configuration) associated with an ePDCCH may be provided and/or received and ePDCCH resources may be monitored and/or decoded based on such information. An indication for support of a reduced bandwidth by the full bandwidth network may also be provided and/or received and control channels in the reduced or narrow bandwidth may be monitored and/or decoded based on the indication. A PRACH preamble and/or a multi-type sub frame definition may also be provided and/or used for support of such a reduced bandwidth.

A method is disclosed that a Mobile Station MS performs at switch-on to search the most favorable target cell in UMTS systems like the 3GPP CDMA—LCR (Low Chip Rate) option at 1.28 Mcps—TDD (Time Division Duplex) mode and the equivalent TD-SCDMA (Time Division—Synchronous CDMA). Signal at the MS antenna is the sum of different RF downlink frames coming from different carriers in the assigned frequency ranges. A DL synchronization timeslot and a BCCH TS0 are both transmitted with full power in the frames, the first one includes one out of 32 SYNC codes assigned on cell basis. Following a conventional approach the absence of a common downlink pilot and without prior knowledge of the used frequencies would force the MS, for all the frequencies of the channel raster stored in the SIM card, the correlation of the received frame with all the 32 SYNCs stored in the MS, in order to detect the BSIC of a cell to which associate the power measures. Following the two-step method of the invention the power measures are performed in two-step scan of the PLMN band without interleaved correlation steps; once a final frequency is selected the respective frame is the only correlated one. At least one frame duration about 5 ms long of the whole 15 MHz bandwidth is acquired, IF converted, A/D converted and the digital set is stored. A rough scan is performed multiplying the digital set by a digital IF tuned in steps wide as the channel band (1.6 MHz) along the 15 MHz band, and filtering the baseband signal with a Root Raise Cosine low-pass filter. The 5 ms baseband signal is subdivided into 15 blocks of half timeslot (337.5 μs) and the power of each block is measured. The power of the strongest block indicates the priority of the respective frequency. The strongest power values are put in a Spectral Table together with respective frame load indicators. The load indicator is the percentage of timeslots in a frame almost equally loaded as the strongest block. The three strongest frequencies are selected for the successive scan. The second step search is performed like the first one but the IF steps are now 200 kHz wide and cover the only 1.6 MHz spectrum around a selected frequency. A final frequency is selected for the successive correlation step. Then the frequency error of the MS reference oscillator is corrected with data-aided techniques and a calibration value stored for successive connections (FIG. 9).

A cellular wireless internet access system which operates in the 2.5 to 2.68 GHz band and which must comply with complex government regulations on power levels, subscriber equipment and interference levels yet which provides high data rates to users and cell sizes of 1½ miles radius or more from base stations with subscriber equipment and antennas mounted indoors. Such base stations are mounted low and use spread-spectrum transmission to comply with interference rules with respect to adjacent license areas. An unidirectional tear-drop coverage pattern is used at multiple cells to further reduce interference when required. Time division duplex is used to allow the system to operate on any single channel of varying bandwidth within the 2.5 to 2.68 GHz band. Backhaul transmission from base stations to the Internet is provided using base station radio equipment, operating either on a different frequency in the band or on the same frequency using a time-division peer-to-peer technique. Different effective data-rates are provided by a prioritization tiering technique.

In accordance with an embodiment, a method of decoding an encoded audio bitstream at a decoder includes receiving the audio bitstream, decoding a low band bitstream of the audio bitstream to get low band coefficients in a frequency domain, and copying a plurality of the low band coefficients to a high frequency band location to generate high band coefficients. The method further includes processing the high band coefficients to form processed high band coefficients. Processing includes modifying an energy envelope of the high band coefficients by multiplying modification gains to flatten or smooth the high band coefficients, and applying a received spectral envelope decoded from the received audio bitstream to the high band coefficients. The low band coefficients and the processed high band coefficients are then inverse-transformed to the time domain to obtain a time domain output signal.

A wireless location system has at least one wireless tag to be located by the wireless location system, wherein the at least one wireless tag transmits two wireless signals having a known time relationship and having different bandwidths. A plurality of receivers is provided wherein a first receiver receives and processes a first of the two wireless signals and estimates a time to arrive (TOA) of the first wireless signal, and a second receiver receives and processes a second of the two wireless signals and estimates a TOA of the second wireless signal at the second transceiver. The plurality of receivers is time synchronized based on a common timing signal. A location server is coupled to each of the plurality of receivers. The location server receives the TOA of the first wireless signal from the first receiver and the TOA of the second wireless signal from the second receiver. The location server calculating a TDOA of the two wireless signals and estimates a position of the at least one wireless tag based on the TDOA