According to a high efficiency coding signal processing apparatus of the present invention, in order to suppress error propagation, effectively correct errors, and reduce a signal deterioration upon repetitive coding processing, a bit rate reduction circuit quantizes a video signal and outputs the resultant signal to low-and high-frequency encoders. A first transmission sequence packet circuit outputs low-frequency components at a predetermined period. A second transmission sequence packet circuit sequences and outputs high-frequency components. Since the low-frequency components and the high-frequency components are separately sequenced and transmitted, the low-frequency components are free from the influence of errors caused in the high-frequency components.

High efficiency coding signal processing apparatus with error propagation influence reduction

A power line communication (PLC) apparatus wherein transmission mode information is encoded into each data packet while maintaining immunity from single bit errors. In the present invention, a power line communication system includes a transmitter/receiver (i.e. transceiver) which is coupled to a power distribution network. Data is transmitted through the power line by the transceiver in packets. The transceiver includes a preamble generator which creates a preamble for each of the data packets and a preamble decoder that decodes the preamble of a data packet and determines word sync for the packet. The preamble generated by the preamble generator consists of a carrier detect interval, a carrier sync interval, a bit sync interval, and a word sync pattern. The transceiver may select either BPSK or QPSK transmission modes on a data packet by data packet basis by encoding information into the packet preamble. Transmission mode information is encoded into the preamble using one of two seven-bit cross compatible word sync patterns for each data packet. Thus, one word sync pattern is used to define a BPSK transmission while the other word sync pattern is used to define a QPSK transmission. The transmitter may send data packets using either BPSK or QPSK on a packet by packet basis by generating the appropriate word sync pattern for each packet. The receiver uses the word sync pattern to determine the receive mode for each packet.

Transmission mode detection in a modulated communication system

Data is stored in and read from a semiconductor memory system including multiple memory integrated circuits in data units commonly exchanged with a rotating memory device. One or more data units to be stored are clustered with a multiplicity of other data units stored in the semi conductor memory to form a cluster of data units. The cluster of data units is compressed, and the compressed cluster of data units is then error correction coded. The compressed cluster of data units is then stored in the semiconductor memory with a multiplicity of contiguous data bits being stored in a single memory integrated circuit. Data compression reduces the number of memory integrated circuits required, thereby reducing both cost and power consumption. Data is stored in and read out of the memory integrated circuits serially such that only a single memory integrated circuit is active at a time, further reducing power consumption.

Power efficient RAM disk and a method of emulating a rotating memory disk

A method, and the apparatus for its implementation, for encoding an input signal includes the steps of transforming an input signal into frequency components, as for example by spectrum transform processing, separating the frequency components into a first signal consisting of tone characteristic components and a second signal consisting of other components, encoding the first signal, and encoding a signal based on the second signal.

Method, apparatus and recording medium for coding of separated tone and noise characteristics spectral components of an acoustic signal

A method for storing and retrieving information on a magnetic storage medium, such as magnetic tape, organizes files into data blocks of variable encoded block sizes. The encoded block sizes indicate file boundaries of files, intrablock data organization and/or interblock data organization to facilitate data retrieval. For example, if encoded block sizes indicate file boundaries, then filemarks are not needed to separate files from each other. During an encoding process, data blocks are assigned corresponding data formats and block sizes are preferably quantized to equal distinctive integer multiples of an encoding constant. Decoding is accomplished by performing a modulo function on the quantized block size to identify corresponding data formats assigned to the data blocks. One practical application of the method of storage and retrieval is recovery of a corrupt or a missing file directory, which references files stored on the magnetic storage medium.

Method for storing and retrieving information on a magnetic storage medium via data blocks of variable sizes

A data transmission and reception apparatus and method capable of selecting either of two modes having the same sampling frequency in which the bit number of one data unit are either m or n (which are integral numbers and m>n), while using the same error correction encoder and decoder for the two modes, by inserting m-n bits of dummy data bits into the n-bit data so as to handle it as m-bit data during the processes of error correction encoding and decoding and eliminating from the error correction encoded data the dummy data and a redundant code of the error correction code formed by the dummy data so that the data transmission rate can be lowered.

Sako Yoichiro Patents Division

Papers

Pcm data transmitting apparatus and method

Methods of and apparatus for data transmission.