Abstract: The present invention relates to an echo canceler for training an echo path estimation without providing a hindrance to a speech. The echo canceler of the present invention includes a pseudo noise generator for generating a certain pseudo noise. This pseudo noise is forcibly supplied to a transmission line for transmitting a far-end talker's voice. Here, in the case where the far-end talker's transmitting speech level is faint or the far-end talker is in a speechless condition, a certain correlation is established between the pseudo noise and a signal of the transmission line for transmitting the near-end talker's voice. Based on such a correlation as just mentioned, a coefficient for generating an echo replica is calculated. Therefore, a training for estimating an echo path is performed based on the pseudo noise and without depending on the far-end talker's voice, thereby generating an appropriate echo replica.

Abstract: For the transmission of variable length coded data blocks, a threshold arithmetic calculation circuit (9) obtains a threshold from an average of the bit lengths of the variable length coded data blocks for each group of such block, and the judgment circuit (10) makes a judgment as to whether or not those variable length coded data blocks have bit lengths exceeding the threshold of the block group to which such data blocks belong. Then, a block divider circuit 11 divides the variable length coded data blocks having bit lengths exceeding the threshold into blocks having small bit lengths. Each block thus obtained is fixedly equalized in bit length to an average length level and transmitted in that condition.

Abstract: The present invention relates to an echo canceler for training an echo path estimation without providing a hindrance to a speech. The echo canceler of the present invention includes a pseudo noise generator for generating a certain pseudo noise. This pseudo noise is forcibly supplied to a transmission line for transmitting a far-end talker's voice. Here, in the case where the far-end talker's transmitting speech level is faint or the far-end talker is in a speechless condition, a certain correlation is established between the pseudo noise and a signal of the transmission line for transmitting the near-end talker's voice. Based on such a correlation as just mentioned, a coefficient for generating an echo replica is calculated. Therefore, a training for estimating an echo path is performed based on the pseudo noise and without depending on the far-end talker's voice, thereby enabling to generate an appropriate echo replica.

Abstract: Datapath elements 1.sub.1 to 1.sub.N can exchange data respectively with local memories 2.sub.1 to 2.sub.N through data buses 6.sub.1 to 6.sub.N, so that parallel operations can be performed. The data bus 6.sub.1, which is connected with one datapath element 1.sub.1, can be connected with the other data buses 6.sub.2 to 6.sub.N through an interconnection network 5, so that by activating one datapath element 1.sub.1 only, data exchange can be made with all of the local memories 2.sub.1 to 2.sub.N through the data buses 6.sub.1 to 6.sub.N and the interconnection network 5. Thus, the multiple datapath elements can perform the parallel operations with being related with the multiple local memories: and a simple configuration is employed such that one datapath element can access to any one of the local memories.

Abstract: A speech freeze-out method in a communication system for transmitting speech information, which is sent from public telephone terminals (1) to a control center (5) through voice channels, from the control center (5) to a base station (8) through time division multiplexing radio frequency channels (6), and from the base station (8) to mobile stations (17) through transponders (13). The freeze-out processing is carried out when the control center (5) feeds the speech information to the time division multiplexing radio frequency channels (6) so that the number of transmission channels from the base station (8) to the transponders (13) is limited within an upper limit value.

Abstract: A minimum/maximum data detector for rapidly detecting the minimum or the maximum data from a plurality of numeric data. In FIG. 1 , one of consecutive numeric data stored in memory 1 is read out by an address designated by a register 2, and is transferred to registers 5 and 6. A counter 9 counts up the number of numeric data which have been stored in register 6. The contents of the registers 5 and 11 are compared by a circuit 4. When detecting minimum data, if the contents of the register 5 are judged to be smaller, the contents of the register 6 and the counted results of the counter 9 are linked in an index linking circuit 10. The linked result is then stored in the specific register 11. The content of the register 2 is incremented by "1" whenever the comparison is executed. Once the read out of one series of consecutive numeric data have been completed, then the numeric data remaining in the specific register 11 is the minimum data.

Abstract: A method of communicating a speech signal over a communication medium which utilizes VOX (Voice Operated Transmitter) control, and a speech signal transmitting unit and a speech signal receiving unit used in said method. The speech signal includes at least one speech-active duration in which actual speech exists and one silent duration in which no actual speech exists. At a transmitting side, the speech signal is analyzed for each of successive frames thereof to determine whether each frame is in the speech-active duration, and is coded for each of successive frames thereof to produce a series of successive coded data of the speech signal. Then, in response to the detection of a speech starting frame of the speech-active duration, the coded data of the speech starting frame is switched to a preamble, and the preamble and the successive coded data subsequent to the speech starting frame are transmitted in the form of a series of successive frames.