Abstract: A transmitter and receiver pair of units for communicating data therebetween. The inter unit transmission in one embodiment is accomplished by using a serial memory associated with the transmitter and a serial memory associated with the receiver. The serial memories are designed to allow data to enter at one speed and to leave at a different speed. The serial memories are reset at precise times. In this manner, the data throughput is increased between the units.

Abstract: A data communication system (100) employs a method and apparatus for adaptively companding (compressing and expanding) data packets therein. A first communication device (e.g., 107) generates a plurality of data packets (201-207) and selects one or more, but not all, of the data packets. The first device then performs a compression of each data packet in a first group of data packets that includes the selected data packets (202-205). The first device transmits the compressed data packets to a second communication device (e.g., 108). Upon receiving the compressed data packets, the second device determines whether the received compressed data packets include one or more of the data packets selected by the first device. When the received data packets include one or more of the selected data packets, the second device transmits a response packet (301) to the first device indicating which, if any, of the selected data packets were received.

Abstract: Digitally-compressed audio and image data of a plurality of programs (logical channels) are distributed and superimposed for every horizontal synchronizing signal period together with identification information of each of the programs in place of a luminance signal of an analog video signal of each of physical channels. Each of the physical channels is superimposed in its frequency and distributed from a signal transmission facility of a broadcasting station. At the receiving side, a desired physical analog channel is tuned and the compressed digital audio and image data superimposed on the tuned video signal are selected and taken as desired logical channel data in reference to program identification information, and the compressed digital audio and image data are decoded to obtain their original audio and moving images.

Abstract: A transcoding and transdecoding unit in a digital mobile radio system, and methods for adjusting their output signals. The unit includes an expander for converting companded digital data into a linear signal; a speech encoder for coding a linearized signal into encoded form; and an amplifier for amplifying the expanded signal. In order that the outbound audio signal not suffer interference due to the raised level, the transcoding unit further includes a level monitor for monitoring the amplitude of the linearized signal and for controlling amplifier such that the signal produced by the amplifier is of a desired level.

Abstract: The present invention provides an optical time compression multiplexing transmission system which suppresses the influence of optical reflection by a simple configuration without degrading transmission efficiency. The present invention is a 1:n (n being a natural number) time division multiplexing point-to-multi-point optical time compression multiplexing transmission system which comprises a decision element for determining whether or not the receiving signal which is outputted from a receiving element is a regular signal, an initialization element for initializing the operation condition of the receiving element when a receiving signal is determined to not be a regular signal by the decision element.

Abstract: In radio communication system in which single frequency simultaneous transmission and reception is performed, a speech audio signal is divided by a predetermined time interval. A transmission time and a reception time are allotted in the predetermined time. A time-compressed signal is transmitted during the transmission time, and a time-compressed signal transmitted from other transceiver is received during the reception time and it is decompressed to the original length. The transmission time and the reception time are alternately repeated to transmit and receive the audio signals substantially simultaneously by a single frequency, and the audio signal is reproduced from the received signal. When communication with a telephone set is to be established, a DTMF signal is used as a dialing signal to call the telephone set from the transceiver. The DTMF signal is time-compressed and then transmitted along with the speech signal.

Abstract: In an information transmission system, in particular a telephone system, the subscribers can be connected to a dial exchange over a line. At the dial exchange end and at the subscriber end of the line are connected bidirectional multiplexers or demultiplexers over a bidirectional modem circuit which modulates and demodulates the data according to the intended transmission. If required, bidirectional compressor and decompressor circuit are connected to the multiplexers and demultiplexers, to which the subscribers are connected through a forward and a backward channel and a SLAC (bidirectional analog-digital converter (CODEC) with subscriber interface circuits (SLIC)), or to which a relaying device of the dial exchange is connected through drive circuits.

Abstract: For quantization of subframe feature vectors representative of subframes identified by subframe indexes in each frame of a time sequential signal, such as an audio or a video signal, a first feature vector of a first subframe of a current frame is extracted with additional extraction of a second feature vector of a second subframe of the current frame and is quantized by a frame vector quantizer unit into a quantized frame vector for the current frame. Using a quantized frame vector for a previous frame and referring to interpolation coefficient vectors, an interpolator interpolates an interpolated feature vector for the current frame. An error vector is calculated between the interpolated and the second feature vectors and is quantized by an error vector quantizer unit into a quantized error vector. The subframe feature vectors are quantized by using the subframe indexes, the quantized frame vectors, the interpolated feature vector, and the quantized error vector.