Abstract: The present invention relates to a filter bank approach to adaptive filtering method using independent component analysis. More particularly, the invention relates to a method of improving the performance of adaptive filtering method by applying independent component analysis that is capable of reflecting the secondary or even higher order statistical characteristics to adaptive filtering algorithm using the filter bank approach. In order to implement the conventional adaptive filter algorithm using independent component analysis to the real world problem, a large number of filter training coefficients are required and also a large amount of calculation is required when a training is undertaken. This results in a very slow learning speed and the deterioration in the quality of result signals.

Abstract: A vector-domain engine configured to perform conditional operations on an operand vector in a programmable logic device is disclosed. The vector-domain engine may receive an instruction from and transmit an output vector to a programmable-logic-device domain. The output vector may be a first or second output vector depending on whether a comparison unit in the engine determines that a bit-field of the operand vector matches a designated pattern. The first output vector may be the operand vector modified by a function unit, and the second output vector may be the operand vector unmodified. A shifter may be employed to shift the bit-field to a desired position in the operand vector. The operand vector may comprise a pattern-defining portion and a data portion. The engine may also be configured to test a predetermined number of sequential operand vectors for the presence of the pattern.

Abstract: A method and system are provided for performing soft error detection for integer addition and subtraction operations without the use of redundant logic. For integer addition and subtraction, compensate logic produces a compensate value utilizing arithmetic logic unit (ALU) result and operands. The compensate value is validated by the validate logic against a predetermined value to determine whether a soft error has occurred. Such compensate logic and validate logic operate on the integer operands and on the result produced by the ALU without redundant carry-propagate hardware.

Abstract: Improved transposition of a matrix in a computer system may be accomplished while utilizing at most a single permutation vector. This greatly improves the speed and parallelability of the transpose operation. For a standard rectangular matrix having M rows and N columns and a size M×N, first n and q are determined, wherein N=n*q, and wherein M×q represents a block size and wherein N is evenly divisible by p. Then, the matrix is partitioned into n columns of size M×q. Then for each column n, elements are sequentially read within the column row-wise and sequentially written into a cache, then sequentially read from the cache and sequentially written row-wise back into the matrix in a memory in a column of size q×M. A permutation vector may then be applied to the matrix to arrive at the transpose. This method may be modified for special cases, such as square matrices, to further improve efficiency.

Abstract: An FIR filter and setting method of filter coefficients thereof enabling the prevention of breakdown of equi-ripple of weighted approximation error and preservation of gain of the pass band into approximately constant. The setting method includes five steps. The initial setting step is that setting of the FIR filter, setting of the band, setting of coefficients of a pre-filter, and setting of initial extreme value point. The first step is that interpolation polynomial equation is generated for interpolating amplitude characteristic from the present extreme value point of the amplitude characteristic of the frequency. The second step is that a new extreme value point is determined from the amplitude characteristic obtained from the interpolation polynomial equation that is obtained in the first step. The third step is that judgement is performed whether or not position of the extreme value is approximated within required range while repeating the first step and the second step.

Abstract: An apparatus and method for DFT processing using prime factor algorithm (PFA) on a selected number P of midamble chip values received by a CDMA receiver, where P has a plurality M of relatively prime factors F, and the DFT process is divided into M successive F-point DFT processes. The P data values are retrieved from a single input port memory and selectively permuted by a controller into parallel caches to optimize factoring with associated twiddle factors stored in parallel registers. The permuted inputs are factored in two or more parallel PFA circuits that comprise adders and multipliers arranged to accommodate any size F-point DFT. The outputs of the PFA circuits are processed by consolidation circuitry in preparation for output permutation of the values which are sent to memory for subsequent DFT cycles.

Abstract: A method and system for generating numerical test cases for testing binary floating-point arithmetic units for addition and subtraction operations, in order to verify the proper operation of the units according to a specified standard. The space for eligible test-cases is compatible with masks which stipulate the allowable forms of the operands and the result, including constant as well as variable digits in both the exponent and significand fields. The test-cases, which are generated randomly, cover the entire solution space without excluding any eligible solutions. All standard rounding modes are supported, and if a valid solution does not exist for a given set of masks, this fact is reported. The method is general and can be applied to any standard, such as the IEEE floating-point standard, in any precision.

Abstract: Apparatus is provided for reliably generating a random number sequence. The apparatus comprises a digital pseudo-random number sequence generator having a first output and an analog random number sequence generator having a second output. The pseudo-random number sequence on the first output and the random number sequence on the second output are combined using logic such as an exclusive-OR operation to generate an output number sequence.

Abstract: In particular, the present invention relates to a method and system for improving the efficiency of computational processes and specifically multiply and accumulate (“MAC”) processes such as the DCT (“Discrete Cosine Transform”) and/or IDCT (“Inverse Discrete Cosine Transform”) using a performance optimized method and associated hardware apparatus.

Abstract: A method and system of efficiently processing a discrete time input signal having a plurality of input signal samples that occur at a first clock rate into a discrete time output signal having a second clock rate that is R times the first clock rate is presented. The method includes receiving the input signal and filtering the input signal with an N-taps finite impulse response (FIR) filter having N filter coefficients. The method reduces the number of required operations and reduces computational errors in the filtering and interpolation of discrete input signals.

Abstract: For calculating the result of an exponentiation Bd, B being a base and d being an exponent which can be described by a binary number from a plurality of bits, a first auxiliary quantity X is at first initialized to a value of 1. Then a second auxiliary quantity Y is initialized to the base B. Then, the bits of the exponent are sequentially processed by updating the first auxiliary quantity X by X2 or by a value derived from X2 and by updating the second auxiliary quantity Y by X*Y or by a value derived from X*Y, if a bit of the exponent equals 0. If a bit of the exponent equals 1, the first auxiliary quantity X is updated by X*Y or by a value derived from X*Y and the second auxiliary quantity Y is updated by Y2 or by a value derived from Y2. After sequentially processing all the bits of the exponent, the value of the first auxiliary quantity X is used as the result of the exponentiation. Thus a higher degree of security is obtained by homogenizing the time and current profiles.

Abstract: In a method for modular multiplication of a multiplicand by a multiplier using a modulus, l multiplication shift values are initially determined by means of a multiplication-lookahead method while taking into account l blocks of consecutive digits of the multiplier. Subsequently, l reduction shift values are determined by means of a reduction-lookahead method for the l blocks of digits of the multiplier. The l multiplication shift values and the l reduction shift values are applied to an intermediate result from a previous iteration step, to the modulus or to a value derived from the modulus, and to the multiplicand, so as to obtain the 2l+1 operands. By means of a multi-operands adder, the 2l+1 operands are combined to obtain an updated intermediate result for an iteration step following the previous iteration step, the iteration being continued for such time until all digits of the multiplier have been processed.

Abstract: A method for implementing a low power and high-speed digital filter having reduced number of adders is disclosed. The method comprises the steps of determining vertical common CSD (Canonical Signed Digit) code words between corresponding CSD code words of adjacent filter coefficients, wherein a vertical common CSD code word in a highest level bit is set as a vertical common subexpression, expressing the vertical common CSD code words out of the CSD code words of each filter coefficient with the vertical common subexpression by shifting and delaying the vertical common subexpression, and synthesizing the expressed vertical common CSD code words of the filter coefficients.

Abstract: A floating point operand testing circuit includes an analysis circuit and a result generator circuit coupled to the analysis circuit. The analysis circuit determines the status of a floating point operand based upon data within the operand. An operand buffer may supply the operand to the analysis circuit. The result generator circuit is responsive to at least one control signal and asserts a result signal if the floating point analysis circuit matches the floating point status to a predetermined format specified by the control signal. The result signal can condition the outcome of a floating point instruction. The result generator may also respond to multiple control signals asserted when testing a single operand for different formats, such as not-a-number (NaN), infinity, normalized, denormalized, invalid operation, overflow, underflow, division by zero, exact, and inexact.

Abstract: Digital filters are provided that include a converter and a data processor. The converter converts successive strings of M successive data elements that occur at a system rate Fs in an input data stream Din to M parallel data elements that respectively occur at a substream rate Fs/M in M data substreams Dsbstrm. At a reduced substream rate Fs/M, the processor generates M convolutions of the filter's quantized impulse response with the M data substreams wherein each of the convolutions is arranged to generate a different one of M successive filtered output signals. Because the convolutions are conducted at the reduced substream rate Fs/M, the filters can operate at increased system rates. Preferably, the digital filter also includes a multiplexer that selects, at the system rate Fs, the M filtered output signals in successive order to thereby form a filtered output data stream Dout.

Abstract: A fast correlator transform (FCT) algorithm and methods and systems for implementing same, correlate an encoded data word (X0-XM-1) with encoding coefficients (C0-CM-1), wherein each of (X0-XM-1) is represented by one or more bits and each said coefficient is represented by one or more bits, wherein each coefficient has k possible states, and wherein M is greater than 1. In accordance with the invention, X0 is multiplied by each state (C0(0) through C0(k-1)) of the coefficient C0, thereby generating results X0C0(0) through X0C0(k-1). This is repeating for data bits (X1-XM-1) and corresponding coefficients (C1-CM-1), respectively. The results are grouped into N groups. Members of each of the N groups are added to one another, thereby generating a first layer of correlation results. The first layer of results is grouped and the members of each group are summed with one another to generate a second layer of results. This process is repeated as necessary until a final layer of results is generated.

Abstract: The ratio of useful-signal power to the power of interference signals at an antenna (ANT) having plural sensors, and at least one sensor is obtained by filtering the antenna output signal with a filter having a transfer function (W(t), W(t, f)) equal to the ratio of two linear functions of the power ({circumflex over (p)}y(t), {circumflex over (p)}y(t, f)) at the output of the antenna to the power {circumflex over (p)}x(t), {circumflex over (p)}x(t, f)) at the input of the antenna (ANT).

Abstract: An apparatus and method for performing enhanced algorithmic processing, including reduced cycle-count fast Fourier transform (FFT) calculations. In one aspect, the invention comprises a user-configurable processor having an extension instruction adapted for reduced cycle-count algorithmic operations. In one exemplary embodiment, the processor is an extensible core, and the extension instruction comprises a 32-bit instruction word linked with existing circuitry in the processor core used for multiply-accumulate (mac) instructions. 16-bit, 24-bit, and dual 16-bit multiply options are available for the multiply/accumulate unit of the processor. The extension instruction is pipelined to the same number of stages as the mac instructions, thereby avoiding unnecessary stalls and increasing performance. A modified accumulator data path used in support of the foregoing instruction is also described.

Abstract: Improved methods of operating a digital data processor to perform binary division include estimating reciprocals of at least selected divisors based on value accessed from a look-up table. For divisors in a first numerical range, the estimation can be based on a value stored in a first look-up table at an index defined by the divisor. For divisors in a second numerical range, the estimation can be based on an index that is a bitwise-shifted function of the divisor. The methods can be applied to scalar and vector binary division.

Abstract: A zero-knowledge proving system includes a proving mechanism for proving equality or inequality of two discrete logarithms and a verifying mechanism for verifying said equality or inequality. The proving mechanism stores public information including a designated operation scheme, two input numbers ? and ?, and two predetermined bases g and h, private information x which is a discrete logarithm of ? to the base g. After converting ?, ? and h to produce ??, ?? and ?? as follows: ??=?r; ??=?r; and ??=hxr, the equality of a log??? and log??? and the equality of logg?? and logh?? are proved. The verifying mechanism verifies the equality of a log??? and log??? and the equality of logg?? and logh??. Then, the received ?? and ?? are checked to determine the equality or inequality thereof, and it is determined whether the proof is acceptable, depending on the verification and the check results.