Abstract: A communication system for transmitting encoded signals over a communication channel is disclosed. The system includes a transmitter, which has a source that is configured to output a plurality of input signals. The transmitter also includes an encoder that is configured to generate a plurality of output signals in response to the plurality of the input signals to output a code word according to the plurality of output signals, wherein the code word has a predetermined algebraic construction for space-frequency coding based upon the communication channel being characterized as a frequency selective block fading channel. Further, the transmitter includes a modulator that is configured to modulate the code word for transmission over the communication channel, and a plurality of transmit antennas that configured to transmit the modulated code word over the communication channel.

Abstract: In a signal cancellation method and device which can cancel input signals quickly and reliably (stably), an input signal is split into a first and second signal. The second signal is split into mutually orthogonal first and second subsignals which are recombined after the respective amplitudes thereof have been adjusted, The first signal is canceled by the third signal thereby obtained. The orthogonal subsignals can undergo amplitude adjustment independently, and the third signal obtained by recombining the subsignals after adjustment can become a cancellation signal having a really selected phase and amplitude over the first through fourth quadrants of the vector plane.

Abstract: A wireless communication apparatus which uses fast Fourier transforms (FFTs) in an orthogonal frequency division multiplexing (OFDM) receiver which incorporates a beam space antenna array. The beam space antenna array may be implemented with a Butler matrix array. The beam space antenna array may be a circular array, vertical array, or a combination of both circular and vertical arrays, for providing the desired angular antenna coverage. In one embodiment, the antenna array is optimized because the FFTs are linear invariant transform operators, whereby the order of operations in the OFDM receiver can be interchanged.

Abstract: Respective nodes N1 to N3 only detect a carrier, and the node N3 sets a random time between a time after a certain period of time t1 and a time until a certain period of time t2 after the carrier of data D11 is gone as a waiting time so as to transmit data within this waiting time. The node N2 transmits ACK data D12 with respect to the data D11 to the node N1 before the certain period of time t1 after the carrier of the data D11 is gone. The node N3 detects the carrier of the ACK data D12 and again sets a random time after the certain period of time t1 until the certain period of time t2 to transmit the data.

Abstract: An intervote modulator (10) includes a majority voting logic unit (12) and an interplex modulator (14). The majority voting logic unit receives plural signal codes (e.g., five codes x1, x2, x3, x4, x5) together with their respective target gains G1, G2, G3, G4, G5 representing the desired transmit power for the individual signal codes. The majority voting logic unit combines three of these five signal codes to form a majority vote composite signal while keeping the other two signal codes uncombined. The majority vote composite signal and the two uncombined signals are then supplied to the interplex modulator as signals s1, s2 and s3. The interplex modulator applies interplex modulation to signals s1, s2 and s3 to form the in-phase and quadrature components of the final composite signal. The majority voting logic unit employs a generalized majority vote involving an interlace of sub-majority votes determined on a chip-by-chip basis.

Abstract: A training sequence is created for space-time diversity arrangement, having any training sequence length, while limiting the training sequence to a standard constellation. Given a number of channel unknowns that need to be estimated, L, a training sequence can be creates that yields minimum means squared estimation error for lengths Nt=kNPRUS+L?1, for any positive integer k?1, where NPRUS is a selected perfect roots-of-unity sequence (PRUS) of length N. The training sequence is created by concatenating k of the length N perfect roots-of-unity sequences, followed by L?1 initial symbols of that same PRUS. Good training sequences can be created for lengths Nt that cannot be obtained through the above method by concatenating a requisite number of symbols found through an exhaustive search.

Abstract: An ultra-wideband transmitter is provided. In one embodiment, the transmitter uses a monopulse of a continuous cyclic signal to phase shift a data pulse. The data pulses and the cyclic signal may be modulated by varying a phase of the data pulses and cyclic signal. The phase shifted data pulse may be used to generate an ultra-wideband pulse for transmission. The modulated data pulses and cyclic signal may be gated such that the data pulse and only a monopulse of the cyclic signal pass through the logic gate. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

Abstract: A process for transmission of information between at least two devices comprises: generating a serial message coded by means of a time sequence of binary transitions called bits; reducing the time length of all bits in the message by changing them into shorter bits, in order to insert additional bits whose half duration falls at the moment in time where the transitions between unchanged bits occurred when no additional bits are inserted; keeping the half duration point of all reduced data bits to the same place as they were in the unchanged message; keeping the total duration of the message containing the additional bits identical to the total length of the unchanged message. The process is compliant with the MIDI standard and allows the increase of the amount of various distinct messages which it is able to convey.

Abstract: A generator of repetitive sets of spreading sequences comprising element (20), for counting and for forming an address and a table (30) containing L sets of S sequences, wherein the address contains q=1+log2S bits, in which one set among L (L=2q) sets is selected and wherein the log2S bits select one sequence among the S sequences in the set.

Abstract: A modem, multiple modem system, and method for operating each is disclosed. Modems in a multiple-modem system save their internal state information in a remote state memory. In the event of a modem failure, a resource controller transfers data-handling to a second available modem. The second modem configures itself using internal state information for the failed modem, as gleaned from the remote state memory. It then takes over the communication channel previously assigned to the failed modem before the modem at the opposite end of the channel discerns the modem failure and prevents call loss. This invention provides redundancy for systems that employ up to several hundred or even thousands of modems, insulating users of these systems from harmful or annoying effects due to partial equipment failure.

Abstract: The present invention provides an apparatus, system and method of peak-to-average reduction of an oversampled signal for a digital communication system. Peak detection 504 and width measurement 504 are advantageously combined in which a peak portion or multiple peak portions of an input signal that exceeds a predetermined threshold is detected and a width of the peak portion is determined. The peak detection and width measurement are further combined with a novel variable width shape generation methodology 506 in which a variable width shaping response is applied 510 to the peak portion responsive to the peak portion width. Additionally, a novel receiver technique 1390 can be included to reduce or eliminate the upstream BER impact using downstream oversampled shaping.

Abstract: A method, a device, and an interface for transmitting data between at least two subscribers, at least one first subscriber transmitting a pulse-width-modulated data signal. The at least second subscriber for its part transmits an asynchronous data signal, which is composed of binary signals, both subscribers transmitting the data, in each case, at a different, specifiable transmission rate. In this context, one of the two transmission rates, in particular that of the second subscriber, is adjusted, in particular increased, so that the pulse-width-modulated data signal of the first subscriber is simulated by a number of the binary signals of the asynchronous data signal.

Abstract: An improved multicarrier modulation system and method, which has the advantages of both isotropic orthogonal transfer algorithm orthogonal frequency division multiplexing (IOTA OFDM) and scalable advanced modulation (SAM), is introduced. The invention is root raised cosine (RRC) OFDM using the most spectrally efficient RRC filter without sacrificing the compact subchannel spacing of OFDM. The invention further provides an adjacent channel interference (ACI) suppression scheme and a modified RRC for better suppressing ACI of RRC OFDM. The ACI suppression scheme can also be applied to SAM with the modified RRC and to IOTA OFDM with a modified IOTA. The invention greatly improves a major problem of conventional OFDM namely ACI due to the use of a wide subchannel filter. Thus, the invention allows OFDM to meet even the strictest ACI requirements, which was not possible by using a conventional raised cosine windowing method.

Abstract: A wireless communication system. The system comprises transmitter circuitry (BST1), the transmitter circuitry comprising encoder circuitry (50) for transmitting a plurality of frames (FR). Each of the plurality of frames comprises a primary synchronization code (PCS) and a secondary synchronization code (SSC). The encoder circuitry comprises of circuitry (501) for providing the primary synchronization code in response to a first sequence (32). The encoder circuitry further comprises circuitry (502) for providing the secondary synchronization code in response to a second sequence (54) and a third sequence (56). The second sequence is selected from a plurality of sequences. Each of the plurality of sequences is orthogonal with respect to all other sequences in the plurality of sequences. The third sequence comprises a subset of bits from the first sequence.

Abstract: A clock data recovery (CDR) circuit to recover a clock signal and data signal from an input signal. The CDR circuit includes a control circuit, a select circuit and a phase adjust circuit. The control circuit generates a first control signal according to a phase relationship between the input signal and a first clock signal. The select circuit is coupled to receive the first control signal from the control circuit and coupled to receive a second control signal. The select circuit is responsive to a select signal to select either the first control signal or the second control signal to be output as a selected control signal. The phase adjust circuit is coupled to receive the selected control signal from the select circuit, the phase adjust circuit being responsive to the selected control signal to adjust the phase of the first clock signal.

Abstract: A pseudo-differential signaling system uses a plurality of signal lines and a single, common reference voltage. Signal line voltages are interpreted only in comparison to the reference line voltage. Within a receiving circuit, the reference line is buffered prior to its distribution to multiple comparators. The system utilizes an active buffer having a bandwidth that is significantly greater than the resonant input frequency of the receiving circuit. In an alternative embodiment, the signal lines are also buffered. In this embodiment, the buffers are implemented with transistor-based source-followers. The buffer associated with the reference line has a larger current capacity than the buffers associated with the signal lines. In yet another embodiment, a comparator produces a correction signal that is equal to the noise present on the signal lines. This noise is then subtracted from the signal voltages.

Abstract: An apparatus and method for controlling the communication frequencies of a software controlled radio by using GPS to calibrate one or more local oscillators and compensating within the digital radio processing for the local oscillator inaccuracies.

Abstract: The invention is a method and demodulator which detects periodic synchronization signals. The method of the invention includes multiplexing orthogonal signals in a wireless transmission into a signal stream; applying the signal stream to a synchronization signal detector which produces an output signal including detection of a unique code representing the synchronization signals within the signal stream; demultiplexing the output signal into orthogonal signals; calculating a function of the demultiplexed orthogonal signals and combining the function of each of the orthogonal signals into a combined output signal; averaging the combined output signal over a time period during which the synchronization signals repeat to produce an averaged signal; detecting peaks in the averaged signal; and synchronizing a demodulator in response to the peaks which demodulates the wireless transmission.

Abstract: The invention relates to an apparatus, and an associated method, in a communication system that is tolerant to interference. The received signal is divided into a real and an imaginary part, and the noise and interference is modeled as a filtered process. The invention solves the interference problem by utilizing the inherent signal structure.

Abstract: A method and signal processing apparatus for reducing the number of bits of a digital input signal (Mi), includes adding a pseudo-random noise signal (Na) to the digital input signal (Mi) to obtain an intermediate signal (Di), the pseudo-random noise signal (Na) being defined by noise parameters (Np), and quantizing the intermediate signal (Di), having a word length of n bits, to a reduced word-length signal (Me) having a word length of m bits, n being larger than or equal to m. The method further includes quantizing the intermediate signal (Di) using a first transfer function which is non-linear, the first transfer function being defined by non-linear device parameters (NLDp).