Abstract: A communications system includes a transmitter device, a receiver system, and a communications link. The communications link couples the transmitter device and the receiver system. The receiver system includes a receiver device and a processor. The transmitter device transmits a data signal. The receiver device receives the data signal from the communications link. The processor is electrically coupled to the receiver device to receive the data signal. The processor regenerates the data signal to compensate for the effects of the communications link on the data signal. Then, the processor outputs the regenerated data signal.

Abstract: Multiple Steiner codes are transmitted as bursts from multiple base stations (182, 184, 186) having one or more transmit elements (174, 176, 178, 180), with successive bursts providing an extended training sequence for use in channel estimation at an addressed unit (172), such as a mobile handset. Accurate channel estimation is possible through the use of Wiener frequency domain MMSE deconvolution (518) combined with frequency domain spatial decoupling matrices, with quasi-orthogonal pseudo-noise sequences (502, 504, 520, 522) allocated to base stations and their antenna elements. The use of Steiner codes to supplement Wiener frequency domain MMSE deconvolution and frequency domain spatial decoupling results in the possibility of allocating only a single training sequence to each base station provided that the training sequence is of sufficient length to encompass all multiple time-translated channel impulse responses (H).

Abstract: A bandpass delta sigma truncator receives a series of first multi-bit digital signals each having a number of data bits, a first number of sign bits and sign extending means for sign extending each of the first multi-bit digital signals to a second multi-bit digital signal having the same number of data bits as the number of data bits in the first multi-bit digital signals, and a second number of sign bits. The truncator outputs from a series of third multi-bit digital signals a series of fourth multi-bit digital signals each having a selected number of the most significant data bits of the third multi-bit digital signals, and a series of fifth multi-bit digital signals each having the remaining number of the least significant data bits of the third multi-bit digital signals.

Abstract: A method of communicating a data bit between memory devices is disclosed, having the steps of: indicating a first value of the data bit by transitioning, between state values, a first signal applied to a first communication line interconnecting the devices; and indicating a second value of the data bit by transitioning, between the state values, a second signal applied to a second communication line interconnecting the devices. Only one of the first and second signals may transition between the state values at any one time.

Abstract: A system and method for signal transmission and reception by narrow band chaotic frequency shift keying includes a forward error correction encoder for receiving input data, a data packetizer in signal communication with the forward error correction encoder, a compression encoder in signal communication with the data packetizer, a radio frequency link in signal communication with the compression encoder, a compression decoder in signal communication with the radio frequency link, a data depacketizer in signal communication with the compression decoder, and a forward error correction decoder in signal communication with the data depacketizer for recovering the input data by controlling the orbits of chaos; where the method includes the steps of transmitting a signal indicative of chaotic frequency shift keyed data, propagating the transmitted signal within a narrow frequency band, and receiving the propagated signal substantially without degradation of the indicated data by controlling the orbits of chaos.

Abstract: A method includes receiving at least two space-time coded signals from an antenna system associated with a first station, determining complex channel state information based on the received space-time coded signals, and sending the complex channel state information to the first station. In an alternative embodiment, a method includes transmitting at least two space-time coded signals in respective beams of a multi-beam antenna array, measuring a channel impulse response for each space-time coded signal at a second station, and sending an indicia of a selected set of least attenuated signals from the second station to the first station. The multi-beam antenna array is associated with a first station. The beams transmit a signature code embedded in each respective space-time coded signal, and the signature codes are orthogonal so that the second station can separate and measure the channel impulse response corresponding to each space-time coded signal.

Abstract: A vehicle-vehicle communication system includes an in-vehicle wire LAN established in a vehicle. The in-vehicle wire LAN includes a plurality of devices connected by optical fiber links. A terminal for radio vehicle-vehicle communication is connected to the in-vehicle wire LAN by the optical fiber link. The terminal receives an optical digital signal in a predetermined format from the in-vehicle wire LAN. The terminal includes a light controlled oscillator and applies the received optical signal to the light controlled oscillator. The light controlled oscillator outputs a transmission signal of a frequency shifted from a predetermined frequency according to the intensity of the applied optical signal. Thus the terminal generates the transmission signal using FSK-modulation technique without converting the format of the optical signal into another format. The transmission signal is transmitted to a device in another vehicle via radio waves.

Abstract: A transmitter for implementing a stream transmission method is disclosed. Optionally, the transmitter first determines an equal weighting of a plurality of stream weights and transmits a plurality of transmission signals as a function of a plurality of data streams and the equal weighting of the plurality of stream weights. Thereafter, the transmitter reiterates as needed a determination of an unequal weighting of the plurality of stream weights and a transmission of the plurality of transmission signals as a function of the plurality of data streams and the unequal weighting of the plurality of stream weights.

Abstract: A method for transmitting an analog datastream includes coding data input into a data input device. The resulting coded data is assembled into coded data blocks. These blocks are transformed into at least one discrete multitone symbol. An initial filter value extracted from the discrete multitone symbol is forwarded to a stored-value determining device, to which a frame alignment signal has been applied. A stored value for a first filtering device is determined as a function of the at least one initial filter value and the frame alignment signal. This value, and the multitone symbol, are applied to the first filtering device, thereby generating a filtered discrete multitone symbol. The filtered symbol is forwarded to a second filtering device to which the stored value determined in the stored-value determining device is applied, thereby generating a transient-compensated discrete multitone symbol. This is then converted into an analog signal for transmission.

Abstract: Described is a transmission system for transmitting a multicarrier signal from a transmitter (10) to a receiver (20). The receiver (20) comprises an equalizer (24) for canceling intercarrier interference which may be included in the received multicarrier signal. The equalizer (24), which preferably is a MMSE equalizer, comprises a reduced complexity filter for deriving a vector of estimated symbols (25) from a vector of received symbols (23). The reduced complexity filter comprises a multiplication of an approximation of an inverse matrix R?1 with the vector of received symbols (23). The approximation of the inverse matrix R?1 is preferably a first order approximation.

Abstract: A method and apparatus for increasing the capacity of a multiple-input and/or multiple-output system. Each sub-stream of a primary data stream is stratified to produce a processed sub-stream whose strata can be separated out and decoded with an acceptable error rate. A sub-stream can be stratified by dividing it into a plurality of sub-stream-components that are processed to obtain strata, with each stratum representing one of the sub-stream-components. The strata are then combined to obtain the processed sub-stream. Stratifying allows a particular processed sub-stream's strata have different transmit features from each other, such as different bit rates, or different power levels, or both. This reduces the interference for some of the strata of each processed sub-stream since as stratum are separated out and decoded they are no longer interference for the other strata. Thus, allowing for a higher overall bit rate for the processed sub-streams.

Abstract: Conventional receiver architectures are based on either frequency/phase tracking or oversampling. Both receiver types typically employ sensitive analog circuits, which create noise, consume power and utilize valuable space in their implementation. The invention adopts a novel approach to phase/frequency tracking that utilizes the edges or zero crossings of the input data waveform to effectively track the remote transmitter clock phase/frequency. This methodology minimizes the use of analog circuitry, thereby reducing the noise domain and the substrate space required for implementation of a tracking device.

Abstract: A CDMA receiving apparatus includes a receiving section, a memory circuit, an estimating circuit and a generating circuit. The receiving section generates a baseband signal from a received radio signal, searches a path having the highest correlation with the received radio signal, generates a path delay quantity for the searched path and generates a demodulated signal as an object signal from the baseband signal based on the path delay quantity. The memory circuit stores at least one SIR value as a previous SIR value. The estimating circuit estimates the SIR value from the object signal and stores the estimated SIR value in the memory circuit. The generating circuit generates a TPC (transmission power control) bit signal for controlling transmission power from the estimated SIR value and the previous SIR value stored in the memory circuit based on the path delay quantity and a reference SIR value.

Abstract: The invention relates to a receiver and a method for initial synchronization of a receiver with the carrier frequency of a desired channel. It can happen during synchronization that the locally generated frequency van indeed be generated correctly although a divider ratio of a variable frequency divider inside the receiver and the reference frequency of a reference oscillator inside the receiver are simultaneously incorrectly set. The incorrect setting is evident in a particularly large skew which is detected in the receiver. In order to avoid such faulty settings even when use is made of budget-priced reference oscillators with relatively large frequency deviations, the skew is evaluated in the receiver and, should a prescribed threshold value be exceeded, a second and a third control signal are generated in order to correct the divider ratio and the reference frequency.

Abstract: A polyphase filter for wireless communication systems includes at least two phase splitting filters each having a variable resistance across their respective outputs. The variable resistance can take any suitable form, such as a MOS transistor biased in the linear (triode) region, a bipolar differential pair, or a digitally switchable resistance. The phase adjustment required for a particular filter can be identified and adjusted through either a closed loop system or an open loop system. Adjustment of the variable resistance reduces quadrature error.

Abstract: The receiver includes: a correlation stage (7) formed of several correlation channels (7?) for receiving intermediate signals (IF) in order to correlate them, in operating channel control loops, with the carrier frequency and specific code replicas of visible emitting satellites to be searched and tracked, each channel having a correlator (8) in which at least one integrator counter (28, 29, 30, 31) provides, at the end of each determined integration period of the correlated signals, a binary output word whose value allows detection of the presence or absence of the visible satellite to be searched and tracked; and a microprocessor for processing the data drawn, after correlation, from the radio-frequency signals.

Abstract: An apparatus/system and a method for optical fiber two-way communication, which enables highly reliable transmission at all times in order to carry out communication at a high transmission speed when an optical fiber or a combination of optical fibers not assumed are used. A signal is transmitted with a predetermined pattern corresponding to each of a plurality of different signal transmission speeds from the signal transmitter of a first terminal to the signal receiver of a second terminal. It is then compared by the signal receiver of the second terminal with a signal of the predetermined pattern. A signal transmission speed is detected which enables transmission and reception on the basis of a signal position where the signal received by the signal receiver of the second terminal and the signal of the predetermined pattern do not coincide with each other.

Abstract: A method of estimating a DC offset value of a signal includes estimating a DC offset value of a preamble part of the signal using a pair of diodes (D1, D2) and a resistor (R) connected in parallel. During receipt of the data part of the signal, the diode pair (D1, D2) is switched out of the circuit by a switch (SW). During reception of the data part, the DC level is estimated using a low pass filter (R,C).

Abstract: There is disclosed a transmitter for transmitting a stream of known symbols and unknown symbols through a transmission channel to a first receiver that receives the transmitted stream of known symbols and unknown symbols distorted by intersymbol interference (ISI) and reduces therein an ISI signal. The transmitter comprises a known symbol distribution controller capable of inserting a plurality of known symbol clusters into an outgoing stream of unknown symbols in an optimum distribution in order to improve the performance of the first receiver.

Abstract: A scheme for reducing jitter in high-speed digital communication by adaptively controlling the loop bandwidth of a receiver PLL to reduce the relative jitter between the recovered data and clock. The scheme uses phase pointer activity to represent the relative jitter. The phase pointer activity is measured and used to control the receiver PLL loop bandwidth. The receiver PLL loop bandwidth is repeatedly incremented or decremented by a step size based on the comparison between a newly measured activity value and the old activity value, until the phase pointer activity reaches a minimum. Because the PLL performance requirement of the transmitter can be relaxed, compatibility with legacy transmitters and multi-vendor transmitters is enhanced. Because tight control of fabrication process parameters of PLLs may be relaxed, the fabrication yield may also be improved.