Abstract: Efficient usage of available spectrum is increased by logically dividing government licensed frequency channels into sub-channels, each of which can individually transmit a signal between a base unit and terminal. The sub-channels are each offset from the center of the frequency channel by a unique offset amount to avoid interference. Power control, sub-channel interference cancellation, and frequency control are employed to minimize the effects of out-of-band sub-channel signals on adjacent sub-channels. Any given sub-channel can be dynamically configured to transmit voice or data signals. Further spectral efficiency is realized using time division multiplexing on some or all of the sub-channels.

Abstract: A Node-B/base station receiver comprises at least one antenna for receiving signals. Each finger of a pool of reconfigurable Rake fingers recovers a multipath component of a user and is assigned a code of the user, a code phase of the multipath component and an antenna of the at least one antenna. An antenna/Rake finger pool interface provides each finger of the Rake pool an output of the antenna assigned to that Rake finger. A combiner combines the recovered multipath components for a user to produce data of the user.

Abstract: A forward link power control mechanism measures the reverse link power control bits which are transmitted on the forward traffic channel. At the remote station, the reverse link power control bits from multiples base stations or multiple signal paths are measured, combined, and filtered to yield an improved measurement of the forward link signal quality. The reverse link power control bits which are deemed unreliable are omitted from use in the power control loop. The remote station generates a set of forward link power control bit in accordance with the measurements and transmits these bits to all base stations in communication with the remote station. Each base station adjusts its gain of the forward traffic channel in accordance to its measurement of the forward link power control bit.

Abstract: In the transmitter which carries out burst transmission using information data as a packet, if the status is divided into four modes, namely, burst stop mode, burst rising mode, burst continuous mode, and burst falling mode, a waveform shaping equipment designed to read out shaped waveform data for each mode from outputs of either of the two memory tables, the first memory table which holds waveform data for specific data patterns used in common in burst rising mode and burst falling mode and the second memory table which holds waveform data for all data patterns used in the burst continuous mode, or a waveform shaping equipment comprising the third memory table which holds waveform data corresponding to all the data patterns used in the burst rising mode and the fourth memory table which holds waveform data corresponding to all data patterns used in the burst falling mode and generating shaped waveform data by synthesizing the two outputs of the third and the fourth memory tables at the time of burst continu

Abstract: A system and method are disclosed for implementing support for increased communication speed between data communication devices, including one or more high speed analog modems, connected to a digital communication network. The high speed analog modems communicate with the digital communication network via analog signaling pathways that also support voice communication across the digital communication network. Following the initiation of communication between an originating communication device and a terminating communication device connected to the digital communication network, determination is made as to whether the communication devices include at least one high speed analog modem and another data communication device capable of communicating at the increased data communication speed.

Abstract: A digital positioning system using digital AM and FM radio stations for use in the environment of a plurality of digital AM and FM (AM/FM) radio stations which comprises a customer service center and a reference station which regularly and passively receives signals from all local digital AM/FM stations and measures variations in key parameters of frequency and wavelength thereof and provides AM/FM correctional data signals corresponding to each AM/FM station frequency and wavelength variation to the customer service center. The customer service center is adapted to provide the AM/FM correctional data signals to each of the digital AM/FM radio stations for insertion into ancillary digital data broadcast from each digital AM/FM radio station.

Abstract: Ultra high spectral efficient Feher Keying (FK) Modulation and Demodulation (Modem), Baseband Processing (BBP), Intermediate Frequency (IF) and Radio Frequency (RF) signal generation and processing methods and implementations, including Clock Modulated (CM) and Shaped Clocked (SC) Transmitters-Receivers (transceivers) are disclosed. Additional embodiments, including Feher Quadrature Shift Keying (FQPSK) and Feher Quadrature Modulation (FQAM), in conjunction with CM and SC are also described. In the FK modulator, specified clock converted and clock shaped signal parameters are generated. These are based on the input data signal patterns and are generated by means of control signals, which are designed in the data input signal interface data signal and/or clock signal encoder units.

Abstract: A sampling system arranged such that a modulated signal received by an antenna and input via a low noise amplifier and a band-pass filter is sampled at a sampling frequency higher than the signal band of the modulated signal by a first sample and hold circuit and is input to an analog decimation filter to remove a frequency component which may turn out to be aliasing noise. The output of the analog decimation filter is sampled with a sampling frequency lower than the sampling frequency of the first sample and hold circuit by a second sample and hold circuit and is digitized by an A/D converter to be demodulated by a demodulator. The sampling system which can convert the modulated signal into a low frequency without using the highly precision mixer circuit or a filter having sharp characteristics may be provided by constructing as described above.

Abstract: Orthogonal transmit diversity is implemented by employing a data splitter (803) to subdivide channel information (801) into at least a first portion of bits (802) and a second portion of bits (804). Each portion is spread with its own Walsh code for eventual transmission to a mobile station via a predetermined carrier frequency. When the number of bits in the first and second portion (802, 804) are small, separate Walsh codes are used to maintain orthogonality. When the number of bits in the first and second portion (802, 804) are relatively large, a time-division multiplex transmission is used to maintain orthogonality. A controller (809) controls the subdivision of the channel information and also an interleaver (308) to further enhance the effects of the diversity transmission. Control information related to the subdivision is transmitted to the mobile station so the channel information can be accurately reconstructed prior to decoding.

Abstract: Auxiliary data is transported in subbands of a primary data signal by hiding the data in the form of colored noise. The colored noise has a spectrum that simulates the spectrum of the primary data signal in each subband. The data to be transported is first converted to a spread spectrum signal. The primary data signal is analyzed to determine its spectral shape. The same spectral shape is imparted to the spread spectrum signal in each subband, which is then combined with the primary data signal for transmission. The spectral shaping can be performed using time domain modeling and synthesis such as linear predictive coding. A plurality of different auxiliary information streams can be transported on the primary data signal. By adjusting the gain of individual spread spectrum signal carrier(s) and the power of the colored noise, the auxiliary information stream(s) can be rendered at any desired level below or above an interference threshold in the primary data signal.

Abstract: A signal processing apparatus having a register unit with the number of bits required for signal processing, which is not larger than predetermined number of bits, and comprising a ROM which inputs, as an address signal, an output signal from the register unit or an input signal to the signal processing apparatus, and uses an input signal to the register unit as a part of an output signal from the ROM. This makes it possible to greatly reduce the cost of a system which executes complex processing yet requires a reduced number of bits in the input signals and a reduced number of bits for the register that is essentially required by reducing the amount of signal processing and the number of electric components, to greatly improve the quality of the apparatus accompanying the reduction in the number of electric components, and to cheaply increase the signal processing functions without decreasing the processing speed.

Abstract: A method for transmitting data between a terminal and a portable data carrier over a wire-free electromagnetic transmission link using a carrier signal which is 100% ASK-modulated in accordance with the data. The carrier signal serving as a clock signal for the portable the data carrier. The significance of an item of data is determined by a position of a shift keying point in the carrier signal within a time slot. The information content of the shift keying point corresponds to a number of N bits, N being greater than or equal to 2. The significance of the N bits is defined by a position of the shift keying point within 2.sup.N possible positions within the time slot. At the start or at the end of a time slot there is a zero time period in which no shift keying point which is assigned to the data to be transmitted occurs, in order to avoid an unacceptably long loss of the carrier signal.

Abstract: A circuit (12) for symbol decision directed feedback synchronization includes a current synchonization clock (45) that provides an initial sampling point and selects a detector corresponding to a current symbol decision. The circuit further includes a plurality of detectors (31, 32, 33, and 34) including the detector corresponding to the current symbol decision, a buffer (736) for storing the output of the detector corresponding to the current symbol decision and a processor (300) for seeking within a predetermined window about the initial sampling point for an optimum phase value to provide an adjustment signal which is used by the processor to adjust a subsequent symbol's sychronization clock to provide an optimal sampling point.

Abstract: An automatic gain control, AGC, circuit comprising with a preferred transition region. A gain correction unit is responsive to an attenuate command and amplify command coming from a feedback system monitoring the AGC's output. The feedback system can individually adjust the delays of both attenuate and amplify commands sent to the gain correction unit. Additionally, the present AGC also includes a transition region detector that monitors the input signal applied to the AGC to from a feedforward system. The transition region detector producing a control output to selectively permit the gain correction unit to respond to an attenuate or amplify command. If the magnitude of the input signal is greater than a predetermined value, then it will place a disable signal on its control output to prevent the gain correction unit from altering its gain.

Abstract: For transmitting voice between subscriber stations of a radio system, particularly a mobile radio telephone system, whereby an analog voice signal is digitally coded by voice frames (S), the voice frames (S) are first converted into voice-coded voice frames (S1). Subsequently, a plurality of these voice frames (S1) is combined to form a multi-voice frame (MSF1). These multi-voice frames (MSF1) are transmitted with error-protection. At the reception side, the multi-voice frames (MSF4) are in turn divided into voice-coded voice frames (S4) and, subsequently, the digital voice information contained in the transmitted voice frames is in turn converted into an analog voice signal.

Abstract: A method is disclosed for encoding and modulating bits of an information stream and transmitting them over a designated channel in a high speed communication system. The method includes the steps of dividing a set of the entire constellation of available points into a finite plurality of zero parity vectors defined by two criteria, namely that (1) the column vectors have odd parity and (2) a group of a predefined integer number of column vectors have a 0 modulus (i.e. be divisible by a given number). Column vectors forming only a partially dimensioned portion of the code (e.g. 4D) corresponding to one discrete baud interval are preferably transmitted in a systematic form and with sufficient coding gain for adaptive DFE equalization and whereby a group of column vectors corresponding to an integer number of successive baud intervals that form the fully dimensioned code (e.g.

Abstract: A demodulation apparatus includes selectors (15r, 15i) for selecting designated data from data of N points outputted from a Fast Fourier-transform circuit (13) and previously-prepared 0 data and outputting the selected data as data of a plurality of series, output order data generators (16, 17) for designating data selected by the selectors and a decoder (20) for decoding data based on data of a plurality of series outputted from the selectors. An interleaved and punctured OFDM-modulated signal can be demodulated by a simple arrangement and in a short period of time.

Abstract: Trellis-enhanced precoding for trellis-coded transmission over channels with intersymbol interference allows coding and shaping gains to be achieved with minimal transmit power penalty for arbitrary signal constellations, provided the intersymbol interference channels are linearly invertible. This technique can be employed for trellis-coded transmission over a variety of communication channels. However, if the channel response exhibits spectral nulls, trellis-enhanced precoding cannot be applied because the corresponding inverse precoding operation at the receiver requires inverse channel filtering. For channels with a spectral null, this inverse operation can result in unlimited error propagation. The present invention allows trellis-coded transmission over channels exhibiting spectral nulls without incurring unlimited error propagation in the receiver. Coding gains are achieved with minimal transmit power penalty, like in the case of trellis-enhanced preceding.

Abstract: A digital communication system modulated signal generation apparatus incorporates a fading simulator for adding fading to a signal to be transmitted to a device to be tested. A baseband signal generation unit generates a digital baseband signal at a predetermined clock rate, and sequentially outputs time information corresponding to the predetermined clock rate. A fading parameter generation unit receives the time information sequentially output from the baseband signal generation unit together with the digital baseband signal, and output a desired fading parameter set in advance in correspondence with the time information. A fading addition operation unit executes a fading addition operation for the digital baseband signal output from the baseband signal generation unit by using the desired fading parameter output from the fading parameter generation unit, and outputs a signal indicating the result. A digital/analog conversion unit D/A-converts the signal output from the fading addition operation unit.

Abstract: In an automobile on-board and/or portable telephone system capable of increasing the capacity of subscribers easily on the basis of changing of the information transmission bit rate, spread codes obtained by multiplying orthogonal spread codes (m in number) by a pseudo-random noise series are assigned to individual channels in the same cell in such a manner that the orthogonal spread codes are multiplied by some types of pseudo-random noise series having different phases, thereby making it possible to maintain the number of channels in the same cell at a value which is a multiple of the number of the orthogonal spread codes.