Multilevel code mates A and B expanded in accordance with the expression a)I (b.sup.K) and B=(a.sup.K)I (b) are compressed to a lobeless basic mate pair by repeatedly compressing corresponding code mate pairs in successive stages to provide diminishing codes of half the number of code bits by amplifying the code mates by a predetermined amplification factor and then adding and subtracting the code mates in accordance with expressions A.sub.i-1 =A.sub.i +B.sub.i.sup.K.sbsp.i and B.sub.i-1 =A.sub....

A digital message transmission system has a transmit side wherein two pulse sequences are sampled at the rate of two plesiochronic data clocks and the sampled sequences are expanded by the insertion of additional information in the manner of "positive stuffing." The two pulse sequences including the additional information are transmitted to the receive side in a pulse frame, the procedure being reversed at the proceed side to decode the message. The momentary phase relationship between the two p...

A method and device for phase synchronization for use particularly where a fixed internal clock signal generator is used for both receive and transmit functions. The phase difference between the incoming pulse train and a fixed internal framing clock is detected by a counting circuit which provides an output signal indicating the interval time of the phase difference. A delaying means coupled to the incoming pulse train delays the same in response to the output signal for the time indicated ther...

A multiplexed data stream monitoring circuit comprises a random access memory for receiving and storing a multiplexed data stream which is transmitted together with a synchronization signal and a data clock. A counter circuit is reset by the synchronization signal and counts the data clock signals to accumulate counts uniquely identified with signals within the data stream which counts are used to address the random access memory. For each accumulated count within the counter circuit, the corres...

A system for the digital conversion of a time division multiplex signal into a frequency division multiplex signal wherein the signals of the individual time multiplex channels are filtered by means of bandpass filters, their sampling rates are increased by the factor N to fA and the output signals of these bandpass filters are combined, by means of a summing member, into the frequency multiplex signal, and/or a system for the digital conversion of a frequency multiplex signal into a time divisi...

TASI apparatus suitable for use with telephone networks employing interregister multifrequency signalling comprising transmission apparatus at a first end of a transmission trunk link having a first plurality of communication channels, the transmission apparatus including means for detecting signals on a second plurality of telephone communication lines on which signals are present to an available one of the first plurality of communication channels and means for applying a delay to the detected...

Expanded multiplexed noise codes including code mate pairs having autocoration functions which upon detectionprovides an impulse autocorrelation function are generated by delaying the inverse of one of the code mate pairs (code b) by a value .tau. and adding it to the other code mate pair (code a) to form a first expanded code mate (code A) while a second expanded code mate (code B) is generated by delaying the inverse of said other code (code a) also by a value .tau., forming the complement the...

A statistical multiplexer is disclosed that includes interfaces for asynchronous and synchronous data equipment, and a CPU/control logic. The CPU/control logic cooperates with the interface for the synchronous data equipment for allocating bandwidth to synchronous data equipment when bandwidth is requested and for deallocating bandwidth when bandwidth is no longer required. The allocation and deallocation of bandwidth is controlled by predetermined control frames generated by the CPU/control log...

A switching system for performing line to line or group to group switching of communication signals modulated by multiplexed noise codes. The noise codes comprise a subclass or set of multiplexed noise codes consisting of code mate pairs which provide an impulse autocorrelation function when detected and furthermore crosscorrelate to zero at a time when the code mate pairs compress to an impulse providing thereby orthogonal operation, meaning that there is no mutual interference between any of t...

This circuit provides for extending a multiplexed address and data bus to remotely located computer peripheral devices. The present circuit eliminates skew of transmitted signals between microcomputers and their associated peripheral devices for lengths of up to one hundred feet. This circuit regenerates the bus timing for the peripheral device to accommodate the skew introduced by the length of cable and its associated drivers and receivers.