Abstract:
An apparatus is provided. A comparison circuit is configured to receive an analog signal. A reference circuit is coupled to the comparison circuit and is configured to provide a plurality of reference signals to the comparison circuit. A conversion circuit is coupled to the comparison circuit and is configured to detect a change in the output of the comparison circuit. A time-to-digital converter (TDC) is coupled to the comparison circuit. A timer is coupled to the comparison circuit. A rate control circuit is coupled to the conversion circuit. An output circuit is coupled to the rate control circuit and the TDC, where the output circuit is configured to output at least one of a synchronous digital representation of the analog signal and an asynchronous digital representation of the analog signal.
Abstract:
A method of performing wireless communications. The method comprises, at a transmitting station, encoding a plurality of symbols into a frame. The method further comprises, from the transmitting station, transmitting the frame via a wireless communication to a receiving station. The frame comprises a plurality of sub-frames, wherein a first sub-frame in the plurality of sub-frames consists of a first number of symbols and a second sub-frame in the plurality of sub-frames consists of a second number of symbols. Finally, the first number differs from the second number.
Abstract:
An integrated circuit 18 is provided that includes a memory 32 and a memory modification component 33. The memory 32 maintains a bits count, a gain, and a tone order for each of a plurality of discrete multi-tone sub-channels. The memory modification component 33 operable to control an in-service modification of at least some of the bits count, the gain, and the tone order using a single bits, gains and tone order table.
Abstract:
A digital signal processor (DSP) includes an instruction fetch unit, an instruction decode unit, a register set and a plurality of work units in communication with the instruction decode unit. A first embodiment calculates two divisions on packed numerators and packed denominators. The DSP work units calculate indexes into a 1/d look-up table and make a final sign correction. A second embodiment calculates an approximation of a vector magnitude of a complex number x+jy. The approximation is based upon √(x2+y2)≈α*max(|x|, |y|)+β*min(|x|, |y|). The DSP work units calculate the absolute values, find the maxima and minima, and form the packed results of two vector magnitude calculations.
Abstract translation:数字信号处理器(DSP)包括与指令解码单元通信的指令获取单元,指令解码单元,寄存器组和多个工作单元。 第一实施例计算包装分子和包装分母上的两个部分。 DSP工作单元将索引计算到1 / d查找表中,并进行最终符号校正。 第二实施例计算复数x + jy的矢量幅度的近似。 近似值基于√(x2 + y2)≈α* max(| x |,| y |)+&bgr; * min(| x |,| y |)。 DSP工作单元计算绝对值,找到最大值和最小值,并形成两个矢量幅度计算的压缩结果。
Abstract:
A method is provided. An analog signal is received. The analog input signal is compared to first and second reference signals to generate a first comparison result, and the first comparison result and a first time stamp corresponding to the first comparison result are registered. A first portion of a digital signal is generated from the first comparison result. At least one of the first and second reference signals is adjusted. A second comparison result is generated if the analog signal reaches an adjusted one of the first and second reference signals within a predetermined interval, and a second portion of the digital signal is generated from the second comparison result.
Abstract:
An apparatus is provided. A comparison circuit is configured to receive an analog signal. A reference circuit is coupled to the comparison circuit and is configured to provide a plurality of reference signals to the comparison circuit. A conversion circuit is coupled to the comparison circuit and is configured to detect a change in the output of the comparison circuit. A time-to-digital converter (TDC) is coupled to the comparison circuit. A timer is coupled to the comparison circuit. A rate control circuit is coupled to the conversion circuit. An output circuit is coupled to the rate control circuit and the TDC, where the output circuit is configured to output at least one of a synchronous digital representation of the analog signal and an asynchronous digital representation of the analog signal.
Abstract:
A method is provided. An analog signal is received. The analog input signal is compared to first and second reference signals to generate a first comparison result, and the first comparison result and a first time stamp corresponding to the first comparison result are registered. A first portion of a digital signal is generated from the first comparison result. If the comparison result remains substantially the same for a predetermined interval, an ADC is enabled to generate a second comparison result at a sampling instant. A second time stamp that corresponds to the sampling instant is generated. The second comparison result and a second time stamp corresponding to the first comparison result are registered, and a second portion of the digital signal is generated from the second comparison result.
Abstract:
In accordance with at least some embodiments, a digital signal processor (DSP) includes an instruction fetch unit and an instruction decode unit in communication with the instruction fetch unit. The DSP also includes a register set and a plurality of work units in communication with the instruction decode unit. A vector math instruction decoded by the instruction decode unit causes input vectors and output vectors to be aligned with a maximum boundary of the register set and causes parallel operations by the work units.
Abstract:
Systems and methods are disclosed for providing automatic gain control of a multi-stage system. A method can include defining at least one parameter that is adapted to at least one of maximize hardware capacity of each of a plurality of gain stages and mitigate part-to-part variations of the multi-stage system. An order is selected for training the plurality of stages based on relative noise dominance for the plurality of stage. For a given stage of the plurality of stages, which is selected according to the selected order, output signals of the multi-stage system are measured over a plurality of gain settings for the given stage. A gain setting of the given stage of the multi-stage system also is configured based on the measured output signals relative to the at least one parameter defined for the given stage. The plurality of gain stages can include an analog equalizer as well programmable gain amplifiers connected in series.
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.