Abstract: Decoder design adaptable to decode coded signals using min* or max* processing. A very efficient means of min* processing or max* processing may be performed within a communication device to assist in the very complex and cumbersome calculations that are employed when decoding coded signals. The types of coded signals that may be decoded using min* processing or max* processing are varied, and they include LDPC (Low Density Parity Check) coded signals, turbo coded signals, and TTCM (Turbo Trellis Coded Modulation) coded signals, among other coded signal types. Many of the calculations and/or determinations performed within min* processing or max* processing are performed simultaneously and in parallel of one another thereby ensuring very fast operation. In a finite precision digital implementation, when certain calculated bits of min* or max* processing are available, they govern selection of resultants from among multiple calculations and determinations made simultaneously and in parallel.

Abstract: A multi-rate encoder and decoder system is disclosed. The multi-rate encoder and decoder system is capable of operating with a mother code or a subset code of the mother code and includes a trellis encoder having a set of inputs and a set of outputs corresponding to the mother code and a select unit capable of removing the set of inputs into the trellis encoder that correspond to the mother code but not the subset code prior to encoding. The multi-rate encoder and decoder system further includes a decoder having a set of decoder inputs and a set of decoder outputs corresponding to the mother code and a decoder select unit capable of ignoring transitions in the trellis code produced by the encoder that belong to the mother code but not to the subset code.

Abstract: A spread spectrum radar performs a target detection process in a first mode. The target detection process includes performing a slide unit detection a plurality of times while sliding transmission code by predetermined number of chips. The slide unit detection includes transmitting the transmission code and performing a sliding-correlation calculation between the transmission code and a reception code. A method for evaluating the spread spectrum radar includes when the spread spectrum radar is changed to a second mode, which is different from the first mode, stopping the slide unit detection to be performed subsequently to the slide unit detection being performed at a time of changing to the second mode; and transferring a data group that indicates sliding correlation values obtained in the slide unit detection being performed at the time of changing to the second mode.

Abstract: A method of transmit power adjustment in multitone communication systems is performed by changing a power spectral density for each subchannel k the power spectral density to the minimum of the power spectral density and a miximum of the power spectral density REFPSD(k)=min(NOMPSD(k), NOMPSD?PCB) where REFPSD(k) is the transmitted PSD at tone k, NOMPSD(k) is the maximum transmit PSD allowed at each tone k, NOMPSD is the maximum value of NOMPSD(k) over all k and PCB is a power cutback level.

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 system and method for signal transmission and reception by narrow band chaotic bi-phase 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 bi-phase 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 repeater having first and second communication terminals that receives signals at either of the terminals and transmits signals responsive to the received signals at the other of the terminals, comprising: a first signal processor that receives V.90 analogue data signals from the first terminal and generates bit streams responsive thereto that accurately reproduce the data in the analogue signals; a second signal processor; and a communication channel linking the first and second signal processors wherein the second signal processor receives the bit streams generated by the first signal processor via the communication channel and transmits V.90 PCM octets responsive thereto via the second terminal.

Abstract: A method of determining a phase between a first signal and a second signal is provided. The first signal and the second signal correspond to signal transmissions between a first device and a second device. The second device periodically moves along a translational axis with respect to the first device in a first direction or a second direction. The method includes assigning a positive or negative value to each of a plurality of positive and negative zero crossings of the first signal. The method also includes counting a numerator and a denominator counter for a predetermined interval. The method also includes calculating a raw phase between the first signal and the second signal by dividing a value of the numerator by a corresponding value of the denominator after the predetermined interval.

Abstract: Disclosed is a sampling circuit for a receiver in a wireless communication device that eliminates the need for separate discrete filtering components that can be expensive and bulky. The system utilizes techniques for ensuring that system components do not become saturated by blocker signals as a result of the removal of the discrete filter. Further, active filters are used in place of the discrete filter only when a blocker signal is present to minimize power consumption. In addition, the dynamic range of a sampling circuit can be altered in the presence of a blocker signal to ensure that the baseband signal is adequately detected.

Abstract: An apparatus generates quasi-complementary turbo codes in a communication system. The apparatus includes a turbo encoder, an interleaver for interleaving symbols output from the turbo encoder according to a given rule, and a code generator for generating the quasi-complementary turbo codes by puncturing and repeating the interleaved symbols from the interleaver. Further, an apparatus decodes quasi-complementary turbo codes in the communication system. The decoding apparatus includes a code decoder for generating code symbols according to a code rate transmitted through depuncturing sub-codes of quasi-complementary turbo codes transmitted from a transmitter and soft combining the sub-codes, a deinterleaver for deinterleaving the symbols output from the code decoder, and a turbo decoder for decoding an output of the deinterleaver.

Abstract: An average tracking mechanism for a data communication receiver is provided. The average tracking mechanism of the receiver is connected to receive an input stream of data samples and is adapted to keep track of an average over a predefined number of most recently received data samples. The average tracking mechanism comprises a calculation unit that is adapted to calculate an approximate value of the average and a storage unit for storing calculated approximate values. The calculation unit is adapted to calculate the approximate value by retrieving a previously calculated approximate value from the storage unit and calculating a weighted sum of the retrieved approximate value and a current data sample. The average approximation technique may be used in a comb filter of a preamble detector in a WLAN receiver.

Abstract: An inquiry message is transmitted successively on each of a first plurality of transmit frequencies (44–48) and thereafter successively on each of a second plurality of transmit frequencies (51), in order to ensure that a first wireless communication apparatus that listens on one of the transmit frequencies will receive the inquiry message. The first plurality of transmit frequencies can also be ensured (25–28) to include a frequency on which a second wireless communication apparatus is listening for the inquiry message. With respect to reception of an inquiry message that is transmitted successively on each of first and thereafter second pluralities of transmit frequencies, after receipt (61) of the initial inquiry message and subsequent expiration of a corresponding backoff period (62), the inquiry message is first listened for on a first frequency of the first plurality of transmit frequencies for a predetermined time (63).

Abstract: In one embodiment, an MLD scheme for a wireless data communication system including steps (a)–(f). Step (a) includes calculating a first vector length for each of a plurality of complex vectors corresponding to a constellation having a plurality of combinations of possible data values. Step (b) includes selecting a subset of the combinations based on the first vector lengths calculated in step (a). Step (c) includes calculating, for a first transmitter, a second vector length for each complex vector corresponding to a combination in the subset. If there are one or more other transmitters, then, for each other transmitter, the method includes implementing steps (d) and (e). Step (d) includes reducing the subset based on the second vector lengths calculated in step (c). Step (e) includes calculating, for a current transmitter, a second vector length for each complex vector corresponding to a combination in the reduced subset.

Abstract: An error correction technique for data communication receivers such as WLAN (Wireless Local Area Network) receivers is provided. The error correction technique is for correcting a frequency and/or phase error in an incoming digitally modulated signal. A constellation manipulator is provided that is adapted to manipulate the phase constellation system of the incoming digitally modulated system by mapping each constellation point of the phase constellation system to a predefined range of phase angles. The predefined range has a width of less than 2?. Further, an error detector is provided that is connected to receive data from the constellation manipulator. The data pertains to the manipulated phase constellation system. The error detector is adapted to evaluate the data to detect the frequency and/or phase error.

Abstract: The amount of interference to communications in Time Division Duplexing (TDD) mode between a TDD mobile and a TDD base station from a mobile operating in Frequency Division Duplexing (FDD) mode that is located near to the TDD base station can be reduced by passing information regarding the interfering FDD signal to the TDD base station, where it is processed and subtracted from the received TDD signal, which includes the interference, so as to obtain the pure TDD signal, as required. Either the FDD data (22), or an FDD signal (23) regenerated from the FDD data or simply the received FDD signal (21) can be passed (24) to the TDD base station. The TDD base station can regenerate an FDD signal, if required, which is then filtered (25) using TDD filters and normalized by correlating (26) and scaling (27) the filtered FDD signal to a received TDD signal. The normalized FDD signal is then subtracted (28) from the received TDD signal to reduce the interference.

Abstract: In some embodiments, a receiver includes a first conductor to carry a magnitude encoded controlled frequency signal (CFS) and a second conductor to carry a complementary magnitude encoded controlled frequency signal (CCFS). The receiver further includes circuitry to receive the CFS and CCFS from the first and second conductors and to decode them to produce an output signal. Other embodiments are described and claimed.

Abstract: A filter and processing sequence is described that efficiently combines and performs two or more tasks required to demodulate a composite 3G (third generation) wireless signal formed by a combination of wideband 3.84 MHz (Universal Mobile Telecommunications System, identiied a acronym “UMTS”, or Universal Mobile Telecommunications System Terrestrial Radio Access, identified as acronym “UTRA”) carriers and narrowband 1.2288 MHz CDMA-2000 carriers. The three tasks, applied to each spectral component of the 3G wireless signal and described in the order of a traditional filtering structure are: Spectral translation, Bandwidth Reduction, and Sample Rate Selection. These tasks are traditionally implemented in three distinct pieces of hardware or software modules.

Abstract: The present invention is related to a system and method for wideband multiple access telecommunication. In the method, a block is transmitted from a basestation to a terminal. The block comprises a plurality of chip symbols scrambled with a base station specific scrambling code, the plurality of chip symbols comprising a plurality of spread user specific data symbols which are user specific data symbols spread by using user specific spreading codes and at least one pilot symbol. In the terminal, at least two independent signals that comprise at least a channel distorted version of the transmitted block are generated. The two independent signals are combined with a combiner filter with filter coefficients which are determined by using the pilot symbol, thus a combined filtered signal is obtained. The combined filtered signal is despread and descrambled with a composite code of the basestation specific scrambling code and one of the user specific codes.

Abstract: A method is proposed for asynchronously transmitting a serial data comprises steps of: providing a first signal and a second signal, the first signal and the second signal having a state in a first interval; and keeping the state of the first signal and changing the state of the second signal into another state in a second interval for transmitting the serial data.

Abstract: Channel estimation and spatial processing for a TDD MIMO system. Calibration may be performed to account for differences in the responses of transmit/receive chains at the access point and user terminal. During normal operation, a MIMO pilot is transmitted on a first link and used to derive an estimate of the first link channel response, which is decomposed to obtain a diagonal matrix of singular values and a first unitary matrix containing both left eigenvectors of the first link and right eigenvectors of a second link. A steered reference is transmitted on the second link using the eigenvectors in the first unitary matrix, and is processed to obtain the diagonal matrix and a second unitary matrix containing both left eigenvectors of the second link and right eigenvectors of the first link. Each unitary matrix may be used to perform spatial processing for data transmission/reception via both links.