Abstract: An exciter (10) is located along an information stream path of a transmission system (12). The exciter (10) supplies an information signal as a drive to an amplifying arrangement (14). A coder (28), programmable to be operative in any of several I/O formats, outputs the information signal that conveys data in a desired code arrangement. A filter (30), programmable to be operative in any of several I/O formats, confines the information signal energy to a predetermined channel bandwidth. A modulator (32), programmable to be operative in any of several I/O formats, modulating the information signal. A corrector/equalizer (34), programmable to be operative in any of several I/O formats, pre-corrects the modulated signal for errors induced in the transmission system. A controller (38) provides program control of the coder (28), the filter (30), the modulator (32), and the corrector/equalizer (34). Thus, the exciter (10) is configurable to handle several formats, such as MPEG2, DVIDEO, and AES3.

Abstract: A transmission system (14) broadcasts a signal. Within the system (14), a power amplifier (20) causes non-linear distortion. A pre-amp component, such as a band-pass filter (32), causes linear distortion. A high power filter (38) is located downstream of the power amplifier (20) and causes linear distortion. A linear equalizer (42) compensates for the distortion caused by the high power filter (38). A non-linear corrector (44) compensates for the distortion caused by the power amplifier (20), and is located downstream of the linear equalizer (42). A linear equalizer (46) compensates for the distortion caused by the pre-amp components (e.g., 32). The compensating components (42-46) are located upstream of the distorting, pre-amp component (e.g., 32). Signal sampling points (70-74) are located downstream of each distorting component (20, 32, and 38). Sampling selectively occurs at one of the sample points (70-74) for use to update compensation.

Abstract: In a digital broadcast transmission system (60), a power amplifier (66) amplifies an information signal to a power level suitable to excite an antenna to emit a broadcast signal. Prior to, an subsequent to, the amplification processing circuitry (68, 70) processes the signal. In particular, the information signal is bandpass filtered. The power amplifier (66) causes non-linear distortion to the information signal. The processing circuitry (68, 70) causes linear distortions to the information signal. A single, memoryful filter (76) pre-distorts the information signal to compensate for all of the linear and non-linear distortions. Preferably, the memoryful filter (76) is a volterra filter. In another embodiment, a memoryful filter (112) pre-distorts an information signal to compensate for linear distortion from a power amplifier (102) and non-linear distortion from pre-amplification processing circuitry (104).

Abstract: A transmission system (14) broadcasts a signal. Within the system (14), a power amplifier (20) causes non-linear distortion. A pre-amp component, such as a band-pass filter (32), causes linear distortion. A high power filter (38) is located downstream of the power amplifier (20) and causes linear distortion. A linear equalizer (42) compensates for the distortion caused by the high power filter (38). A non-linear corrector (44) compensates for the distortion caused by the power amplifier (20), and is located downstream of the linear equalizer (42). A linear equalizer (46) compensates for the distortion caused by the pre-amp components (e.g., 32). The compensating components (42-46) are located upstream of the distorting, pre-amp component (e.g., 32). A interpolation component (22) is located between the three compensating components (42-46) and the distortion causing components (20, 32, and 38) to increase a rate of the signal, such that the compensation occurs at a lower rate of the signal.

Abstract: A transmission system (14) broadcasts an information signal. Within the system (14), several components (e.g., 20-24) cause distortion to the information signal as the signal is processed and proceeds toward a broadcast antenna. Specifically, the group of distortion causing components (20-24) is identified as a first group, and is arranged in a sequence along a signal path (12) toward the antenna. The first group of components (20-24) performs various functions, including amplification, but each subjects the information signal to distortion shifts away from intended values. A second group of components (e.g., 28-32) modifies the information signal to compensate for the distortion shifts imposed by the first group of components (20-24). The second group of components (28-32) is located upstream of the first group of components (20-24).

Abstract: A transmission system (14) broadcasts a signal. Within the system (14), a power amplifier (20) causes non-linear distortion. A pre-amp component, such as a band-pass filter (32), causes linear distortion. A high power filter (38) is located downstream of the power amplifier (20) and causes linear distortion. A linear equalizer (42) compensates for the distortion caused by the high power filter (38). A non-linear corrector (44) compensates for the distortion caused by the power amplifier (20), and is located downstream of the linear equalizer (42). A linear equalizer (46) compensates for the distortion caused by the pre-amp components (e.g., 32). The compensating components (42-46) are located upstream of the distorting, pre-amp component (e.g., 32). Signal sampling points (70-74) are located downstream of each distorting component (20, 32, and 38). Sampling selectively occurs at one of the sample points (70-74) for use to update compensation.

Abstract: An adaptive apparatus (10) for compensating a linear distorting action to an information signal within a non-ideal transmission system (12). Within the system (12), an information signal proceeds to a transmitter (34) that has an amplifier (62). A sample signal is coupled-off from the transmitter (34). The linear distorting action of the system (12) includes shifting of at least one aspect of the signal away from its intended value. A linear pre-equalizer (54), located along a signal stream of the information signal to the transmitter (34), pre-equalizes the information signal. An adaptive equalization determination (70), connected to receive the sample signal and the information signal outside of the signal stream to the transmitter (34), determines an amount of pre-equalization required from the linear pre-equalizer (54) to compensate the linear distorting action of the system (12).

Abstract: A transmission system (14) broadcasts a signal. Within the system (14), a power amplifier (20) causes non-linear distortion. A pre-amp component, such as a band-pass filter (32), causes linear distortion. A high power filter (38) is located downstream of the power amplifier (20) and causes linear distortion. A linear equalizer (42) compensates for the distortion caused by the high power filter (38). A non-linear corrector (44) compensates for the distortion caused by the power amplifier (20), and is located downstream of the linear equalizer (42). A linear equalizer (46) compensates for the distortion caused by the pre-amp components (e.g., 32). The compensating components (42-46) are located upstream of the distorting, pre-amp component (e.g., 32). Signal sampling points (70-74) are located downstream of each distorting component (20, 32, and 38). Sampling selectively occurs at one of the sample points (70-74) for use to update compensation.

Abstract: The present invention provides an apparatus for providing error correction data in a digital data transfer system. The apparatus receives a clock signal and provides a first signal using the clock signal. Information data is received and a second signal is provided using the information data. The information data is received in groups which each have a first predetermined number of elements. A plurality of &agr;ROMs provide Galois Field multiples in look-up tables. The &agr;ROMs are addressed using the first signal to provide a first address component and using the second signal to provide a second address component. Modula mathematics are performed utilizing the values from the &agr;ROMs to generate error correction data. The error correction data is in groups each having a second predetermined number of elements. A RAM is accessible by a Trellis encoder and has an array for holding the information data elements and error correction data elements.

Abstract: An adaptive apparatus for compensating the non-linear distorting action of an amplifier in a transmission system. I-channel and Q-channel memories store a plurality of digital pre-distortion correction values. The memories are addressed using a predetermined number of significant bits of an incoming, original information signal to retrieve I-channel and Q-channel pre-distortion correction values. The I-channel and Q-channel pre-distortion correction values are combined, digitally, with I-channel and Q-channel components of the original information signal to pre-distort the original information signal. The pre-distorted signal, in real format, is supplied to the amplifier, and a feed-back sample signal is coupled-off of the output of the amplifier. A comparison is made between the original information signal and the feed-back sample signal in digital format and in the complex domain (I/Q). In response to the comparison, the pre-distortion correction values (I/Q) in the memory means are modified.

Abstract: An apparatus for compensating signal distortion via use of a feedback path, with reduced analog to digital conversion capacity requirements. In one embodiment, the apparatus is part of a transmission system which has an analog amplifier that distorts an information signal. Prior to the amplification, the information signal is provided in a digital format, processed digitally, and converted to analog for input to the amplifier. A sample signal is coupled off of output of the amplifier and applied along the feedback path. An analog-to-digital converter is located along the feedback path. A pre-distortion corrector is at the end of the feedback path. The pre-distortion corrector operates upon the source information using feedback data indicative of the amplifier distortion. Specifically, the information signal is pre-distorted (prior to input to the amplifier) to compensate for the distortion of the amplifier.

Abstract: A test signal generator presents a test signal of pseudorandom data in a format which simulates the Grand Alliance Transmission Layer Signal for the 8- or 16- vestigial sideband (8/16-VSB) signal for Advanced Television (ATV) systems. An actual (non-test) Transmission Layer 8/16-VSB signal for ATV is in a particular format with properly formatted sync information and includes data which have been randomized, Reed-Solomon coded, interleaved, and trellis coded. The test signal generator provides data in the particular 8/16-VSB format which simulates the Grand Alliance transmission signal.