Abstract: The apparatus and method describes herein shows a system of digitizing analog or digital electronic or optical signals with very high single bit serial digital data streams which digitizing is suitable to automatically adapt the transmission of multiple types of analog and digital signals. The system is especially well suited for allowing the coupling and transmission of signals.

Abstract: A broadcasting method for simultaneously broadcasting analog and digital signals in a standard AM broadcasting channel is provided by: broadcasting an amplitude modulated radio frequency signal having a first frequency spectrum, wherein the amplitude modulated radio frequency signal includes a first carrier modulated by an analog program signal; and simultaneously broadcasting a plurality of digitally modulated carrier signals within a bandwidth which encompasses the first frequency spectrum, each of the digitally modulated carrier signals being modulated by a portion of a digital program signal, wherein a first group of the digitally modulated carrier signals lying within the first frequency spectrum are modulated in-quadrature with the first carrier signal, and wherein second and third groups of the digitally modulated carrier signals lie outside of the first frequency spectrum and are modulated both in-phase and in-quadrature with the first carrier signal.

Abstract: The present invention provides for an analog and/or digital radio broadcast transmission system and radio receiver therefor, which includes a control signal having an item of control information concerning another, different type of transmission/receive system. The receiver is a hybrid receiver able to receive both types of signals. When the same program material is available on both of the different systems, the control signal is used for switching the different systems so that the receiver receives the program on the system which provides the best reception.

Abstract: A radio information broadcasting and receiving system consisting of three major parts: an FM transmitter station with subcarrier multiplexing capability, an FM receiver apparatus with subcarrier demodulation capability, and a computer connected in combination with the receiver apparatus. The FM transmitter station includes sources of main programming signals first digital data signals and second digital data signals. The first and second digital data signals are modulated by subcarrier 1 and subcarrier 2 frequencies respectively and are mixed with the main program signal and then transmitted. The transmitted signals are received by a receiver apparatus including an FM receiver circuit and an FM demodulator circuit for receiving the broadcast signal and demodulating it. The demodulated main program audio frequency signal is applied through a filter/deemphasis circuit and amplifier to speaker to provide an audio output.

Abstract: A radio communication apparatus of this invention includes a mode designation switch for selectively designating and inputting a desired mode from an analog mode and a digital mode, and a mode storage circuit for storing the desired mode designated and input by the mode designation switch and has a mode setting control function, a mode comparison function, and a mode change control function. In order to establish a radio link, control is performed to set a mode for transmitting a communication signal in accordance with the desired mode stored in the mode storage circuit. After the start of transmission of the communication signal, the mode comparison function compares the mode set by the mode setting control function with the desired mode stored in the mode storage circuit.

Abstract: A data demodulation logic unit (200) and method used therein, adaptable to multiple data protocols, including an arithmetic logic unit (205) that is architecturally optimized to demodulate multiple data protocols under the control of a hardware based state machine (209) that operates in a selectable mode that corresponds to one of multiple data protocols.

Abstract: A dual-mode telephone has transmit and receive channels suitable for cellular telephony, and is operative in analog and digital modes of communication. Each of the channels has parallel branches of circuitry wherein the circuitry of one branch accommodates voice signals in accordance with an analog protocol and the second branch accommodates voice signals processed by digital compression and expansion circuitry. The digital compression circuitry, which is employed for outgoing voice signals, and the digital expansion circuitry, which is employed for incoming voice signals, constitute a vocoder operative under control of a microcontroller unit. Operation of the vocoder during a digital transmission mode introduces a digitally processed quality to received voice signals, this characteristic being distinguishable from the voice quality of pulse-code modulation employed in the analog communication mode.

Abstract: The recovery of each signal in a transmitted signal including a pair of superimposed signals is improved by the use of linear prediction. The pair of signals includes various combinations of analog and digital signals, e.g., an analog signal sample superimposed upon a digital signal sample, or a digital signal sample superimposed upon another digital signal sample. In a first embodiment, prediction coefficients for the analog signal are generated from the received signal. These coefficients are then used to recover the analog and digital signals from the received signal. In a second embodiment, the analog signal recovered, pursuant to the first embodiment, is considered a tentative estimate of the analog signal, and prediction coefficients for this tentative analog signal estimate are formed and used to generate final estimates of the analog and digital signal.

Abstract: A spread spectrum modulating apparatus includes an oscillator outputting a carrier. A frequency multiplier multiplies a frequency of the carrier by a predetermined integer N1. A frequency divider divides the frequency of the carrier by a predetermined integer N2. A spread code generator uses an output signal of the frequency divider as a clock signal, and generates a spread code in response to the clock signal. A power supply feeds a dc bias voltage. An operation device executes a predetermined logic operation between the spread code and the dc bias voltage of the power supply. A switch selectively feeds an input information signal to either the oscillator or the point of connection of the power supply to the operation device, selecting between PSK and FSK as primary modulation. An output signal of the operation device and an output signal of the frequency multiplier are multiplied to execute a spectrum spreading process.

Abstract: The present invention provides a novel Geometric Harmonic Modulation (GHM) system. The GHM system operates in two modes, a preamble mode and a traffic mode. During the preamble mode, n+1 frequencies are each offset by a predetermined phase offset in a transmit unit and passed through a channel to a receive unit. The set of phase offsets is used as the spreading code in the transmit unit, and also acts as an `address` of receive units to transmit to. The receive unit monitors preamble signals to determine the phase offsets. When it recognizes a set of phase offsets, or `address`, which pertains to itself, the receive unit stores the phase offsets and uses these phase offsets to despread and decode the appended message. After the preamble mode is finished, the transmit unit enters the traffic mode and requests the message to be transmitted from the message source. A traffic carrier waveform is created by multiplying tones, each having its specific phase offset.

Abstract: In a simultaneous voice and data communication system, a stream of signal points is partitioned into a plurality of symbol blocks, each symbol block including a data segment and a control segment. The data segment carries information from a user, i.e., user data, while the control segment provides control information. A voice signal is then added to at least a portion, or all, of the signal points of each symbol block to provide for simultaneous voice and data transmission to an opposite endpoint. The control information may represent information from a secondary data source, and/or may include information about the characteristics of the succeeding block, e.g., the user data rate, and information pertaining to characteristics of the communications channel.

Abstract: A mobile radio communication system is provided with a base station apparatus connected to a wire circuit, a mobile radio station apparatus which is connected to the base station apparatus by means of a radio circuit, a mode designation device for selecting either an analog mode or a digital mode when radio communication is to be performed between the base station apparatus and the mobile radio station apparatus, and a mode-informing device for informing the base station apparatus of the mode designated by the mode designation device.

Abstract: An apparatus and method for automatically controlling a reference frequency (120) in a receiver (104) that receives either analog (116) or digital (136) information signals. The receiver (18) includes a frequency translator (109) for translating a carrier frequency (137) to an intermediate frequency (118) and maintaining the intermediate frequency (118) at a desired value responsive to the reference frequency (120). A first measure of frequency error (211, 212) is detected between the reference frequency (120) and the intermediate frequency (118). A second measure of frequency error (125, 126) is detected between the reference frequency (120) and the intermediate frequency (118). A current signal (213) is produced responsive to the first measure of frequency error (211, 212) when the receiver receives the analog information signal (116) and responsive to the second measure of frequency error (125, 126) when receiver receives the digital information signal (136).

Abstract: The base station includes for monitoring the quality of a radio link between the base station and mobile stations, a generator (1, 2, 3) for generating a square wave signal (CK) having a monitoring signal frequency; and a filter (4) for generating a monitoring signal (CS) from the square wave signal (CK). The frequency of the monitoring signal is set by a control (12) having two modes of operation; in the first mode of operation, the control controls the generator to transmit an analog monitoring signal by maintaining the frequency of the square wave signal (CK) at a constant value throughout the duration of the monitored radio link, and in the second mode of operation, the control controls the generator (1, 2, 3) to transmit a digital monitoring signal by varying the frequency during the monitored radio link in response to changes in the logical state of the monitoring signal between a first frequency corresponding to the first logical state and a second frequency corresponding to the second logical state.

Abstract: A channel selecting apparatus simultaneously selects both the modulation signals, which are simultaneously received at different channels where modulation signals having a continuous phase and digital modulation signals having a discontinuous phase are located. As both the modulation signals are propagated on the same transmission path or approximately the same inclination of transmission path, modulation signals existing on different channel frequencies suffer approximately similar frequency shift from the transmission path before being inputted to the channel selecting apparatus.

Abstract: A mobile phone includes a modem, hereinafter referred to as a cellular radio modem. This cellular radio modem supports two modes of operation--an analog mode, where the cellular radio modem provides an analog signal for transmission; and a digital mode, where the cellular radio modem provides a digital bit stream for transmission. During operation, i.e., the existence of a data connection to a far-end modem, the cellular radio modem is alerted by the cellular network to switch to the appropriate mode--analog or digital. The cellular radio modem then switches and continues transmission in the new mode. In this embodiment, the far-end modem is part of a modem-pool located within the Mobile Telecommunications Switching Office of the cellular network. The far-end modem automatically detects this switch by the cellular radio modem and itself switches to the appropriate mode.

Abstract: A simultaneous voice and data modem performs "voice-activated" data rate changes to improve the transmission quality of the voice signal. In particular, when the simultaneous voice and data modem detects that a local telephone set has gone "off-hook," the simultaneous voice and data modem selects a signal space with a lower symbol density, which, although resulting in fewer bits per symbol, provides for a higher quality voice transmission.

Abstract: A device is provided for rapid data exchange between a telecommunications transmitter (T) and a data processor (PC), and includes a driver (TSV) and an intermediate line (FAST-LINK). The driver (TSV) is arranged between a terminal adapter (ADAPT) of the telecommunications transmitter (T) and an interface of the data processor (PC). The intermediate line (FAST-LINK) is arranged between the driver (TSV) and the data processor (PC). The telecommunications transmitter (T) is connected to a telecommunications network (ISDN) having a signalling channel and a user channel.

Abstract: A dual-mode radiotelephone terminal includes a .pi./4-shift DQPSK modulator (11). A dual-mode modulation is achieved by mixing an output of a transmitter oscillator (16) with an output of an offset oscillator (18) to form an injection signal (LO) at a final transmitter frequency, the injection signal being further modulated with a quadrature modulator in a digital mode of operation. In an analog mode of operation the transmitter oscillator or the offset oscillator is frequency modulated and the quadrature modulator is disabled with a bias signal, thereby passing the frequency modulated injection signal without substantial attenuation. The LO signal is regenerated and also phase shifted with a circuit (35) having a frequency multiplier (30) and a frequency divider (34). The circuit outputs two local oscillator (LO) signals (LOA and LOB), each of which directly drives an associated quadrature mixer (36, 38) of the modulator.

Abstract: A dual-mode RF signal power amplifier combining network is comprised of two branches, each having a power amplifier (200 and 201). The first branch contains a non-linear mode power amplifier (200) while the second branch contains a linear mode power amplifier (201). The non-linear mode branch also has an RF switch (210). Both branches are coupled to a common output node (220). The common node (220) is coupled to a filter (107) before going to an antenna (106). The non-linear mode power amplifier (200) operates when an FM signal is to be amplified, while the linear amplifier (201) is biased in an off state. The linear mode power amplifier (201) operates when a digital signal is to be amplified, while the non-linear amplifier (200) is biased in an off state. The RF switch (210) removes the non-linear amplifier (200) from the circuit to prevent loading the on state linear amplifier (201).

Abstract: A compatible analog channel unit for a digital cellular telephone system services both analog and digital mode subscribers on the same system hardware. The analog channel unit which may be configured by the service provider to permit easy upgrading of service during the life of the equipment without additional capital expense to the service provider. All analog system functions required of an analog cellular base station are provided in firmware and executed on commercial digital signal processors (DSPs). The same DSPs, when down-loaded with different firmware, perform TDM/TDMA related functions as required of a digital cellular base station. A system operator can configure channel units from a remote location by simply downloading the appropriate firmware. The channel unit firmware, whether analog or digital, is downloaded into the system hardware according to the assigned mode. This permits dynamic channel allocation according to system requirements.

Abstract: Data transfer for a time division multiplex (TDM) bus in a communication system that includes a plurality of communication nodes wherein each communication node is allocated at least one time slot of the TDM bus can utilize the following protocol to improve flexibility. When a communication node has an information packet to transmit, it must determine whether it is changing from a first information packet type to a second information packet type message. If a change from transmitting a first information packet type to transmitting a second information packet type is determined, an information type transition message is transmitted via the allocated time slot during a first frame cycle. Upon receiving the information type transition message, at least one other communication node stores the information type transition message.

Abstract: A power amplifier used in a portable, radio frequency transmitter is switched between different modes of operation when transmitting differently modulated carriers. The first mode of operation corresponds to amplitude modulation (AM), while a second mode corresponds to angle modulation techniques such as frequency modulation (FM). A switching network alters the impedance of the power amplifier to match network for matching the impedance of the transmitter antenna in order to achieve maximum efficiency in each mode of operation. Various switching methods and impedance matching circuits are disclosed.

Abstract: A digital exciter (30) for selectively modulating digital or analog input data. The digital exciter includes a digital signal modulator (32) and a digital quadrature modulator (DQM)(36) comprising two digital signal processors (DSPs). The signal modulator is controlled by a control (40). An operator can selectively determine whether the digital exciter is used for modulating either two level or four level NRZ digital data and whether the device is to provide linear modulation or frequency modulation (FM) of the input signal. An interpolator (38) interpolates a 662/3 kHz timer interrupt rate used in the signal modulator to a 400 kHz rate, thereby reducing the processing load on the DSP comprising the DQM by simplifying the sine and cosine values used in the quadrature modulation. An operator can select from among a plurality of operating parameters on a menu for controlling the signal modulator, either from a local or a remote video display terminal (VDT).

Abstract: A receiver for selectively receiving high frequency signals from analog modulated signals and digital modulated signals. The receiver has an intermediate frequency signal circuit for selecting a desired channel of the high frequency signals and for frequency-converting the high frequency signal of the selected channel into an intermediate frequency signal, a demodulator for demodulating the intermediate frequency signal, which is adapted to be capable of demodulating modulated signals in a variety of modulation systems, the demodulator including at least a digital section, and a controller for controlling the demodulator to be able to discriminate between the analog modulated signals and the digital modulated signals, based on a demodulated signal output from the digital section of the demodulator and to be switched into a demodulation mode suited for modulation system of the selected channel of the high frequency signals.

Abstract: A receiver circuit for receiving both digital and analog modulated signals has a high frequency amplifier for amplifying digital and analog modulated high frequency signals, a down conversion block for converting an output signal from the high frequency amplifier into an intermediate frequency signal, a root Nyquist bandpass filter for limiting the intermediate frequency signal from the down conversion block to a frequency band based on root Nyquist characteristics, an intermediate frequency signal linear amplifier for linearly amplifying the intermediate frequency signal from the root Nyquist bandpass filter, a limiter amplifier for limiting to a constant amplitude the intermediate frequency signal from the intermediate frequency signal linear amplifier, a received signal intensity detector for detecting received signal intensity information from the intermediate frequency signal from the intermediate frequency signal linear amplifier, a synchronizing clock signal generator for generating a synchronizing clo

Abstract: At a transmitting end, frequencies used to a construct a digital signal are substantially removed from an analog signal by a notch filter circuit to produce an interim signal which is then combined with the digital signal as by combining to produce a composite analog signal that is transmitted to a receiving end. At the receiving end the frequencies used to construct the digital signal are substantially removed from the composite analog signal by a notch filter circuit. In this way the digital signal can be transmitted simultaneously with the analog signal without errors that could be introduced by the analog signal, and with only a slight change to the frequency spectrum of the analog signal. This can be used in telephone communications for sending caller ID digital data over the same line carrying a voice signal. Caller ID data is sent FSK encoded and only those frequency used for the mark and the space are attenuated in the received voice signal before it reaches the telephone's speech circuit.

Abstract: When remote control data has been input during calling in analog mode, a mobile radio communication apparatus according to the invention outputs a predetermined first voice frequency signal indicative of the remote control data and transmitting the signal to a radio link, and outputs the first voice frequency signal. Further, when remote control data has been input during calling in digital mode, the mobile radio communication apparatus outputs message data indicative of the remote control data and transmitting the message data to a radio link, generates a second voice frequency signal corresponding to the input remote control data and also the first voice frequency signal, and outputs the second voice frequency signal before the message data is transmitted.