Abstract: Conventional transceivers do provide some compensation for in-phase/quadrature (I/Q) imbalance. However, these techniques do not separately compensate for I/Q imbalance for the transmitter and receiver sides of the transceiver. Here, a transceiver is provided that allows for compensation of I/Q imbalance in the transmitter and receiver irrespective of the other to allow for a more accurate transceiver.

Abstract: An apparatus is provided. In the apparatus, an input to index (I2I) module maps a complex input into a real signal. A real data tap delay line is coupled to the I2I module and includes N delay-elements. A complex data tap delay line is configured to receive the complex input and includes M delay elements. A set of K of non-linear function modules is also provided. Each non-linear function module from the set has at least one real input, at least one complex input, and at least one complex output. A configurable connectivity crossbar multiplexer couples K of the N real tap delay line elements to real inputs of the set non-linear functions and couples K of the M complex tap delay line elements to complex inputs of the set non-linear function modules.

Abstract: A method of wireless handover in a broadcast network (FIGS. 5 and 8) is disclosed. A wireless receiver (FIG. 4) receives a first signal (N) from a first transmitter (f1). The receiver measures a signal strength (RSSI) of the first signal. The strength of the first signal is compared to a first threshold (T0). The receiver receives a second signal (N+3) from a second transmitter (f3) in response to the step of comparing. The first and the second signals are sent to an application processor (120). The wireless receiver continues to receive the first and second signals until the application processor terminates receiving one of the first and second signals.

Abstract: In conventional radio frequency (RF) systems, transmitters will usually convert baseband signals to RF so as to be transmitted. As part of the conversion process, the transmitters will perform digital preditortion (DPD), which uses feedback from a power amplifier. However, there are usually mismatches between the in-phase (I) and quadrature (Q) paths within with feedback loop. Traditional IQ correction filters were ineffective at providing adequate compensation for these mismatches, but here a filter is provided that provides adequate out-of-band compensation by use of frequency selectivity.

Abstract: Crest factor reduction algorithms described herein may be used to improve power amplifier efficiency during low signal power conditions compared to traditional static threshold techniques. Techniques described herein insure that the signal power level at the output of the crest fact reduction block is held constant relative to the input power level under all signal power level conditions. Two different solutions may be implemented together or separately to achieve the desired conditions. The first technique provides constant ratio between input power and output power. Constant ratio of peak and average output levels keeps the amount of crest factor reduction applied to the signal constant, irrespective of the signal power level. A second technique is to hold signal power level constant in respect to the amount of crest factor reduction applied.

Abstract: Traditionally, for multi-band communication systems, independent signal chains for each of the different bands are employed. By using such an architecture, there are a large number of components, and there is substantial power consumption. Here, transmit processor is provided that enables transmission across multiple bands using few components (namely, fewer signal chains), while also provided for digital predistortion.

Abstract: Conventional transceivers do provide some compensation for in-phase/quadrature (I/Q) imbalance. However, these techniques do not separately compensate for I/Q imbalance for the transmitter and receiver sides of the transceiver. Here, a transceiver is provided that allows for compensation of I/Q imbalance in the transmitter and receiver irrespective of the other to allow for a more accurate transceiver.

Abstract: Previously, when designing receivers for radio frequency (RF) or wireless communications, designers chose between time-interleaved (TI) analog-to-digital converters (ADCs) for intermediate frequency architectures and dual channel ADCs for direct conversion architectures. Here, similarities between TI ADCs and dual channel ADC were recognized, and an ADC that has the capability of operating as a TI ADCs and dual channel ADC is provided. This allows designer to have greatly increased flexibility during the design process which can greatly reduce design costs, while also allowing the manufacturer of the ADC to realize a reduction in its operating costs.

Abstract: Systems and methods for power amplifier pre-distortion are provided. The systems and methods of power amplifier digital pre-distortion disclosed herein may include a generic pre-distorter architecture which can implement a variety of Volterra cross terms involving single dimension convolutions (first order dynamics). For hardware implementations, this generic pre-distorter is further fine-tuned to provide a choice between different sets of cross terms that can be selected for a given PA for optimal performance. The novel pre-distorter architecture provides flexibility to trade off memory depth for additional Volterra terms and vice versa. A further novelty is the ability to trade off both memory depth and cross terms for a higher sample rate operation, which may enable higher order non-linear pre-distortion, or support for higher signal bandwidths. A poly-phase non-linear filtering mode allows for this flexibility.

Abstract: Previously, when designing receivers for radio frequency (RF) or wireless communications, designers chose between time-interleaved (TI) analog-to-digital converters (ADCs) for intermediate frequency architectures and dual channel ADCs for direct conversion architectures. Here, similarities between TI ADCs and dual channel ADC were recognized, and an ADC that has the capability of operating as a TI ADCs and dual channel ADC is provided. This allows designer to have greatly increased flexibility during the design process which can greatly reduce design costs, while also allowing the manufacturer of the ADC to realize a reduction in its operating costs.

Abstract: An apparatus and system are provided for crest factor reduction (CFR). Preferably, a peak from the wideband signal is detected. A gain from the magnitude of the peak and a threshold can then be calculated. Based on this information, each carrier's contribution to the peak can be approximated, and a cancellation pulse coefficient for each carrier from its contribution to the peak can be calculated. A base cancellation pulse can be calculated from the cancellation pulse coefficients for each carrier, and a cancellation pulse can be calculated from the base cancellation pulse and the gain, which can then be applied to the wideband signal.

Abstract: A method of wireless handover in a broadcast network (FIGS. 5 and 8) is disclosed. A wireless receiver (FIG. 4) receives a first signal (N) from a first transmitter (f1). The receiver measures a signal strength (RSSI) of the first signal. The strength of the first signal is compared to a first threshold (T0). The receiver receives a second signal (N+3) from a second transmitter (f3) in response to the step of comparing. The first and the second signals are sent to an application processor (120). The wireless receiver continues to receive the first and second signals until the application processor terminates receiving one of the first and second signals.

Abstract: A system and method for reordering tones of a DMT signal within a communication system is described. Cross tone correlated noise in a received signal is identified and rearranged such that tones with correlated noise are spread out throughout the received signal before being processed by a decoder such as, Viterbi decoder. In an embodiment, two tones with the most correlated noise are placed at each end of the sequence of tones presented to the Viterbi decoder. In some embodiment, the tones with correlated noise can be spread such that two adjacent tones with correlated noise have a minimum distance of at least three tones between them at the input to the Viterbi decoder. In other embodiment, tones in the received signal can be processed in various kinds of interleavers for reordering according to the interleaver scheme.

Abstract: A system and method for reordering tones of a DMT signal within a communication system is described. Cross tone correlated noise in a received signal is identified and rearranged such that tones with correlated noise are spread out throughout the received signal before being processed by a decoder such as, Viterbi decoder. In an embodiment, two tones with the most correlated noise are placed at each end of the sequence of tones presented to the Viterbi decoder. In some embodiment, the tones with correlated noise can be spread such that two adjacent tones with correlated noise have a minimum distance of at least three tones between them at the input to the Viterbi decoder. In other embodiment, tones in the received signal can be processed in various kinds of interleavers for reordering according to the interleaver scheme.

Abstract: A noise determiner for use with a communications system, a method of determining noise in a communications system and a digital subscriber line (DSL) modem. In one embodiment, the noise determiner includes (1) a crosstalk identifier that detects directly a noise source in a frequency domain from observed noise associated with the communications system and (2) a crosstalk estimator coupled to the crosstalk identifier and that provides a corresponding level of the noise source.