Abstract:
An improved digital video signal processing circuit, for common use in the recording and playback modes of a video tape recorder, has a chrominance processing circuit for processing the chrominance signal of the input digital composite video signal through a first baseband mixer, a chrominance processor, and a second baseband mixer, and a luminance processing circuit for frequency modulating/demodulating the luminance signal, so that the processed chrominance and luminance signals can be added together to form an output digital composite video signal. The improved digital circuit automatically regulates the frequencies of the mixing signals for both mixers using line stepping signals obtained from a horizontal line sweep generator in the luminance processing circuit. The possibility of phase errors is eliminated, and quadrature errors in the chrominance signal are prevented.
Abstract:
To realize the transfer function in a digital filter circuit:H(z)=b(1-z.sup.-kn)(1-z.sup.-n).sup.m-1 /(1-z.sup.-).sup.m,the following sections are cascaded: a multiplier for multiplying by 2.sup.-q ; m-1 integrators, each including a delay element which provides a delay equal to the period of the input sampling frequency; and mth integrator including a delay element which is reset by the output sampling clock; a sampling device which is switched at the output sampling clock rate; m-2 differentiators, each including a delay element which provides a delay equal to the period of the output sampling clock; and an (m-1)st differentiator including k delay elements which each provide a delay equal to the period of the output sampling clock.
Abstract:
Method and apparatus for active noise suppression in stereo multiplex signals particularly in an automotive radio receiver includes an insertion circuit where the disturbed signal section is replaced with an insertion signal formed by sampled signal values/signal sections which are located before and/or after the disturbed signal section. Basic-delay stages ensure that only those sample values are used for the insertion signal which are separated from the respective instant of insertion by a time interval having an integral relationship nT to the period T of a carrier contained in the stereo multiplex signal (where n is a positive integer).
Abstract:
Carrier generation facility for a switchable digital demodulator (D) of digital MPX signals (mpx1) with associated pilot signal (p1) which are locked to an arbitrary clock signal (t1). A pilot signal PLL (10) generates a first carrier signal (x1.1, x2.1) and a second carrier signal (x1.2) by means of a first value allocator (15) and a second value allocator (20), respectively. According to the MPX signal (mpx1) to be demodulated, a control device (60) delivers a start value (i0) and at least one phase correction value (k1, k2). The start value (i0) sets the capture range of the pilot signal PLL (10) for the pilot signal (p1) according to the respective standard. In a first correcting device (16) and/or a second correcting device (23), the phase correction values (k1, k2) correct the system-inherent phase deviations of the first carrier signal (x1.1, x2.1) and/or the second carrier signal (x1.2).
Abstract:
An integrated circuit for decoding an analog audio signal includes a tuner that receives the analog audio signal and provides a sound intercarrier frequency signal. A digital demodulator receives and digitizes the sound intercarrier frequency signal to provide a digitized sound intercarrier frequency signal, and digitally demodulates the digitized sound intercarrier frequency signal to provide a digitized multichannel television sound (MTS) demodulated signal. A digital broadcast television system committee (BTSC) compatible decoder receives and decodes the digitized multichannel television sound (MTS) demodulated signal, and provides a summed (L+R) audio output signal and a difference (L−R) audio output signal.
Abstract:
Audio source selection circuit (QW) for an audio signal processor with inputs for source signals (F1, F2, NA, NB) provided by at least one source (Q1, Q2), with a processing device (V) which forms pairs of signals from the source signals, with a settable source selection logic (Qs) to which the channels of the processing device (V) are applied, and with outputs coupled to signal outputs of the settable source selection logic (Qs) and each forming an output channel (Co1, Co2, Co3), the processing device (V) including an automatic audio mode setting device which generates suitable intermediate channels (Cz1, Cz2, Cz3, Cz4) from the source signals (F1, F2, NA, NB) according to a source- and application-related mode.
Abstract:
A digital sound processor for processing multiple standard sound signals and including an audio source which is connected to a digital control input of the sound processor and generates, via externally or internally applied control signals, an audible signal or an audible signal sequence which is fed via the output devices of the sound processor to reproducers.
Abstract:
A circuit is disclosed for modifying a first signal and a second signal from a signal source providing at least two signals. The circuit including devices for forming signal components from the first and second signals. The signal components are then combined into a modified first signal and a modified second signal by means of a first combining device and a second combining device, respectively.
Abstract:
An improved method for digital interpolation of signals for a second interpolation filter is disclosed which permits a high signal/noise ratio with a minimum amount of circuitry for an overall system comprising first and second interpolation filters. The method for digital interpolation of signals requires multiplying delayed input values locked to a first signal by corresponding weighting factors which are dependent on a time-difference value determined by the interpolating instant and the time grid of the first clock signal. The weighting factors are determined by an impulse response in the time domain. The associated transfer function has an attenuation characteristic in the frequency domain which, with respect to the stop bands, is limited essentially to the alias regions located at the frequency multiples of the first clock signal. Each of these alias regions is assigned at least two adjacent zeros, or in the presence of double-order zeros, at least one of the alias regions and the associated periodic alias regions are assigned at least one further zero of the transfer function.
Abstract:
A central processor for digital signal processing operates at a high clock rate. In the central processor, data is transferred and processed largely in parallel and simultaneously. A buffer is inserted in the data link between a data memory and an ALU by means of at least three data buses so that within one clock period, all necessary data transfers for a two-address operation of the ALU are performed by using the buffer. In particular, a unidirectional data bus and a bidirectional data bus transfer data from the buffer to the ALU, and the bidirectional data bus transfers the result of an ALU operation back to the buffer. Simultaneously with the transfers between the buffer and the ALU, a data transfer is performed between the data memory and the buffer. The data transfers and the data processing are controlled by a control unit in which a fixed program is stored segment by segment. The use of pipelining in the control unit permits a high processing speed. The use of delayed branching is supplemented by the skip technique. The central processor does not utilize interrupt control. Rather, a scheduler selectively changes the sequence in which a program operates in response to an external or internal task request only at the end of the segment currently being executed so that the current program segment is concluded without interruption.