Abstract: A data demodulating technique for binary data defined by a pulse code modulated signal. The technique involves digitizing the data signal read by a magnetic head from the stripe of a magnetic card. The time interval between peaks in the digitized signal is determined to provide peak interval values. The peak interval values form the basis for determining the end of a character and also by a pattern matching technique against idealized data form the basis for determining the character itself.

Abstract: A system and method of amplitude modulation is described in which first and second 180 degrees out-of-phase signals are produced and are each amplified by one of two (different amplification factor) non-linear amplifiers. One of the signals is amplified using constant amplification by a first non-linear amplifier to generate a relatively small amplified signal. The other of the signals is modulated using variable amplification by a second non-linear amplifier to generate a relatively larger amplitude modulated signal. The two resulting 180 degree out-of-phase signals are combined, such that the smaller signal effectively cancels out lower level distortion exhibited by the larger amplitude modulated signal. Alternatively, a symmetrical structure can be used for generating AM signals which include phase reversals of the carrier.

Abstract: There is provided a channel estimating apparatus and method in a radio communication system.

Abstract: For reducing a peak value in single-carrier modulated or multi-carrier modulated digital transmitter signals, the peak value is first determined from a plurality of transmitter symbols contained in the digital signal. If a predetermined value is exceeded, a replacement symbol is generated which replaces a predetermined transmitter symbol. The replacement symbol is so chosen that it lowers the peak value and is convertible into the original transmitter symbol without error using a coding which was used to create the transmitter symbols.

Abstract: A base station transmits a first spread spectrum signal having a first code. It receives and analyzes an impulse response of multipath components of a second spread spectrum signal having a second code to determine a first received component. The second signal is time synchronized with the first spread spectrum signal. A distance determination is made based on in part a timing difference between the second code of the received second signal and the first code of the base station's transmitted first signal and the determined first received components for that base station's received second signal.

Abstract: A multiple access method for use in a point to multipoint communications network includes a step of allocating a respective unique variable (&rgr;1, . . . , &rgr;i, . . .

Abstract: Road transmission antennas (4a, 4b) are disposed along a road, each radiating a single cell (E) with electromagnetic waves at the same frequency and of the same content. A vehicle mounted device (3) receiving the waves from the road transmission antennas (4a, 4b) performs antenna pattern diversity reception. When entering a wave blocking area of a large vehicle, a small vehicle is provided with seamless communications with a stationary station (FIG. 1).

Abstract: A receiver for a digital broadcasting service have a compatibility between tuning to a desired channel at a short period of time and an improve ment of a bit error rate (BER) characteristics. In a case where a target wave is fluctuated, to prevent the receiver from having a significant declination of BER characteristics and to ensure the reproduction of high quality images, the receiver includes an automatic gain controller including a loop filter in which the frequency range of the loop filter can be switched according to an output of a synchronous state discriminator. The frequency band of the loop filter is selectively adjusted to one setting designed for minimizing the duration for tuning a desired channel before a synchronous state is established. After the synchronous state established, the frequency band of the loop filter is switched to another setting designed for enhancing BER characteristics.

Abstract: Spread spectrum technology is being used in more and more wireless applications. Generally applications of spread spectrum include a fixed spread spectrum code size. In addition in applications that employ time domain duplex, some may employ a fixed duty cycle, for example 50% broadcast and 50% receive, for broadcast and receive functions. Many applications, such as cordless phones, also feature a fixed sampling rate for an input signal. By building systems in which these variables are not fixed but variable manufacturers can make generic type spread spectrum controllers which can be used in a variety of applications. These same circuits can also be controlled to give current devices enhanced characteristics by adjusting data rate for changing conditions, thereby enhancing their performance. By allowing the spreading code to be reduced in length, the data rate of the transmitted signal can be increased without adjusting the bandwidth of the amplifiers used to amplify the transmitted signal.

Abstract: This proposal describes an optimized synchronization (SYNCH) symbol sequence to be used in transmission systems, which are currently under standardization. The synchronization symbol is constructed using specially designed OFDM (orthogonal frequency division multiplexing) symbols with an optimized sequence, which is mapped onto the modulated subcarriers. The resulting synchronization symbol consists of several repetitions in the time domain. Using the proposed sequence the resulting synchronization symbol achieves a high timing detection and frequency offset estimation accuracy. Furthermore the burst is optimized to achieve a very low envelope fluctuation (low Peak-to-Average Power Ratio) and a very low dynamic range to reduce complexity on the receiver and to save time and frequency acquisition time in the receiver. The proposed sequence is furthermore optimized with respect to all other synchronization symbols that are used to construct the synchronization and training preambles for the BCCH-DLCHs.

Abstract: A device and method for generating a binary quasi-orthogonal code in a CDMA communication system. The method comprises generating an m-sequence, and specific left and right sequences having a good full correlation property with the m-sequence; column permuting the specific left and right sequences in a column permutation method used when converting the m-sequence to a Walsh orthogonal code, and connecting the left sequences to the right sequences to generate mask candidates; operating the mask candidates and Walsh orthogonal codes having the same length as the mask candidates to generate quasi-orthogonal code candidate families; and selecting a quasi-orthogonal code out of the generated quasi-orthogonal code candidate families, the selected quasi-orthogonal code satisfying a partial correlation property with the Walsh orthogonal codes, and selecting a mask related to generation of the selected quasi-orthogonal code.

Abstract: Power level calculating circuit 10 and 11 calculate power levels at the input and output terminals, respectively, of a channel filter 6, and an adder 13 computes the difference between the two calculated power levels. An adder 13 corrects (i.e., subtracts) the difference obtained in the adder 12 from an AGC control signal output of an integrating circuit 9, and reports the correction output as antenna terminal reception power level to a base-band circuit 7. The correction output of the adder 13 is obtained by taking the extent of attenuation outside a desired wave band in the channel filter 6, and thus corresponds to accurate antenna terminal reception power level.

Abstract: A method and apparatus reduces the complexity of initial synchronization in mobile terminals operating in TDMA communications systems. A TDMA transmission comprises multiple repeating time slots marked by synchronization words. Initial synchronization requires locating at least one time slot in the received signal. Information in a slot is received as a sequence of symbols at a defined symbol rate. The mobile terminal receives the TDMA transmission for a period longer than one time slot and samples a baseband version of the received signal at M times the symbol rate. This oversampling produces M symbol-rate sample sets, with each sample set corresponding to one of M sampling phases. The mobile terminal performs a FFT on each one of the plurality of the M sample sets after raising it to the nth power, where n is based on the number of modulation phases used to transmit the symbols.

Abstract: A Digital Impairment detection scheme which is designed for providing reliable estimate of digital impairments such as PAD, and CODEC type in the presence of digital impairments such as Robbed Bit Signalling and non G.711 complaint network CODECs and analog impairments such as IMD, noise and changing line conditions. This estimate is used to derive optimum transmit symbol constellations for a modem connected digitally to a trunk so as to maximize its data transmission rate.

Abstract: A transmission method for implementing variable rate transmission. Part of the baseband processing of a transmitter based on a CDMA transmission scheme is described. A transmitted information sequence in the form of a digital signal is phase modulated by a phase modulator 105. An orthogonal code generator 101 selects, in response to rate information of the transmitted signal, the orthogonal code to be generated. The bit rate of the orthogonal code the orthogonal code generator 101 generates is double the maximum transmission rate. The modulated transmitted signal is multiplied by the orthogonal code corresponding to the rate information with a multiplier 103. The transmitted signal, which is multiplied by the orthogonal code corresponding to the rate information, is further multiplied by a spreading code sequence with a multiplier 104 to be spread into a CDMA signal, and is transmitted under power transmission control based on the rate information.

Abstract: A communication circuit is designed with a detector circuit (720) coupled to receive a first signal. The detector circuit is arranged to produce a multipath signal corresponding to a number of paths of the first signal. A comparator circuit (726) is coupled to receive the multipath signal and a threshold signal. The comparator circuit is arranged to produce a diversity signal in response to a comparison of the multipath signal and the threshold signal. The diversity signal has a first logic state for enabling diversity and has a second logic state for disabling diversity.

Abstract: A correlator and matched filter for use with coded transmission, such as CDMA, form new codes from the sums and differences of the original codes, where only one of the new codes is non-zero for each element position and effect hardware savings using the new codes.

Abstract: A method for improving network compatibility, said method including but not limited to the following: receiving a first-protocol data-link layer packet having a first-protocol address, the first-protocol data-link layer packet encapsulating a network-layer packet bound for a network layer entity native to a second-protocol data link layer environment; directly translating the first-protocol data-link layer packet to at least one second-protocol data-link layer packet encapsulating at least a part of the network layer packet, where the at least one second-protocol data-link layer packet has addressing comprising a pre-defined second protocol companion address of the first-protocol address; and transmitting the at least one second-protocol data-link layer packet into the second-protocol data-link layer environment. In other embodiments, hardware and/or software effect the foregoing referenced method.

Abstract: The invention relates to a reception method and a receiver for a TDMA radio system, in which received signals include a desired signal and one or more interference signals, which desired signal and interference signal include a predetermined sequence, by which the signals can be separated from each other. The receiver searches for the most interfering interference signal and forms a signal estimate of the desired signal using the predetermined sequence of the desired signal. The receiver then forms the first residual signal, which describes the difference between the signal estimates of the received signal and the desired signal; the receiver then forms the second residual signal, which describes the difference between the received signal and the co-channel signal estimate. The receiver compares the first residual signal with the second residual signal and based on the comparison, selects either single detection or joint detection to detect the received signal.

Abstract: A spectrum analysis engine (SAGE) that comprises a spectrum analyzer component, a signal detector component, a universal signal synchronizer component and a snapshot buffer component. The spectrum analyzer component generates data representing a real-time spectrogram of a bandwidth of radio frequency (RF) spectrum. The signal detector detects signal pulses in the frequency band and outputs pulse event information entries output, which include the start time, duration, power, center frequency and bandwidth of each detected pulse. The signal detector also provides pulse trigger outputs which may be used to enable/disable the collection of information by the spectrum analyzer and the snapshot buffer components. The snapshot buffer collects a set of raw digital signal samples useful for signal classification and other purposes. The universal signal synchronizer synchronizes to periodic signal sources, useful for instituting schemes to avoid interference with those signals.