Abstract: The invention relates to a digital transmission system having a receiver which includes an equalizer for estimating transmitted binary symbols, from a sequence of sample values (6) of a received signal distorted by a transmission channel, by a reduced-state sequence estimation method or a reduced-state single symbol estimation method (11). To provide a receiver featuring high reliability combined with a clear state reduction of the estimation method, a minimum-phase substitute system (14) distorts the sample values received after received after a known training sequence (27) in the sequence of sample values (6)in the received order, and a maximum-phase substitute system (14) distorts the sample values (6) received before a known training sequence (27) and to be processed in reverse order for forming an estimate (11) for a received signal. The number coefficients of the impulse response which are reduced by the state reduction and used for the estimation, render the estimation inaccurate.

Abstract: A digital transmission system comprising a receiver, the receiver including a receiver input stage and a digital memory for storing a sequence of binary symbols of sample values, formed in the receiver input stage, of a signal distorted by a transmission channel, and an equalizer for forming a sequence of binary estimates from the sample values by an impulse response of a substitute system describing the transmission channel, the impulse response being determined by first correlations of coefficients of a known training sequence with the sample values of a part of the known training sequence extended by at least one binary symbol.

Abstract: A process for distributing an aggregate rate and total transmitting power of a data stream over a plurality of channels in which the sub-rate (R.sub.i), capable of being transmitted over one channel, is calculated for each selected channel in accordance with the equation ##EQU1## R.sub.i being the sub-rate in the i-th channel, N.sub.i the average noise power first determined in the i-th channel, and D' being the number of actually used channels out of the channel group.

Abstract: A method of digital telecommunication via an electrical cable is provided, whereby the symbols of a data stream to be transmitted are supplied as a transmission signal to a transmission path, after undergoing a digital-to-analog conversion. The transmission signal is received and sampled at the end of the transmission path on a receiving side. To further process the received signal on the receiving side, a Viterbi decoder operating on the basis of a trellis diagram is used. The Viterbi decoder uses a number of feedback filters to determine branch or path metrics in the trellis diagram, where this number is a function of the number of states in the trellis diagram. To determine the branch metrics in the trellis diagram, separate first feedback filters (8) are only used up to a specifiable number of symbol intervals in the trellis diagram, or up to a specifiable length of feedback filters for all states in the trellis diagram.

Abstract: A method for digital transmission of messages is indicated, in which each digital transmission symbol in a data stream to be transmitted is represented by one of several different possible signal values. The signal values of the transmission symbols are routed to a predistortion system, which counteracts their distortion in the transmission path, and whose output signal is transmitted through a linked transmission path. The transmitted signal is scanned at the end of the transmission path, it is then processed further and routed to a decoder. The maximum amplitude of the signal in the receiving-end decoder is limited by limiting the number of different possible signal values corresponding to each transmission symbol.

Abstract: Methods and apparatus for demodulating a received communication signal employing coherent demodulation and decision-directed channel estimation are disclosed that have a significant gain compared to a receiver employing noncoherent demodulation. This is particularly so for spread spectrum communication systems such as the uplink specified by the TIA/EIA/IS-95 mobile communication standard, in which an orthogonal modulation scheme combined with convolutional coding and interleaving is used. The coherent demodulation methods and apparatus do not require a pilot signal, and thus can be used in communication systems that are originally designed for use of noncoherent demodulation.