摘要:
A circuit for use with an amplification circuit having a predistortion datapath portion, a power amplifier portion and a gain portion. The predistortion datapath portion can output a predistorted signal based on the input signal. The power amplifier portion can output an amplified signal based on the predistorted signal. The gain portion can output a gain output signal based on the amplified signal. The circuit comprises a digital predistortion adaptation portion and a combiner. The digital predistortion adaptation portion can output a predistortion adaptation portion output signal. The combiner can output an error signal. The predistortion adaptation portion output signal is based on the input signal, the gain output signal and the error signal. The error signal is based on the difference between the predistorted signal and the predistortion adaptation portion output signal.
摘要:
A circuit for use with an amplification circuit having a predistortion datapath portion, a power amplifier portion and a gain portion. The predistortion datapath portion can output a predistorted signal based on the input signal. The power amplifier portion can output an amplified signal based on the predistorted signal. The gain portion can output a gain output signal based on the amplified signal. The circuit comprises a digital predistortion adaptation portion and a combiner. The digital predistortion adaptation portion can output a predistortion adaptation portion output signal. The combiner can output an error signal. The predistortion adaptation portion output signal is based on the input signal, the gain output signal and the error signal. The error signal is based on the difference between the predistorted signal and the predistortion adaptation portion output signal.
摘要:
A method of determining indicators for matrix codewords in a matrix codeword codebook, where the matrix codewords are adapted for communicating information between a transmitter and a receiver. The method includes providing a lookup table that is associated with multiple codewords that are associated with a codebook. The lookup table has m rows, and each row in the lookup table has a one-to-one correspondence with a codeword in the multiple codewords. Each row has p entries and each of the p entries holds a codeword indicator that identifies a codeword in the multiple codewords. The (i,j)th entry in the lookup table holds the codeword indicator identifying the jth most similar codeword to the codeword associated with the ith row according to a similarity metric, where 1≦i≦m and 1≦j≦p, and the m rows include a row k. The method includes identifying a first indicator in the row k by testing each of the indicators in the first p entries of row k to determine which of the indicators in the first n entries identifies a reduced search codeword that best satisfies a selection criterion, wherein, n has a predetermined value and 1≦n≦p, and, in relation to the other remaining indicators in the first n entries of the first row, the first indicator identifies the reduced search codeword that best satisfies the selection criterion.
摘要:
An apparatus is provided to determine pre-distortion for a nonlinear system. The apparatus comprises a datapath and a power amplifier. The datapath employs predistortion data to generally linearized the power amplifier. To generate this predistortion data, an indirect learning circuit and a direct learning circuit can be employed. The indirect learning circuit is generally coupled to the amplifier circuit so that it can iteratively adjust predistortion data during an indirect learning mode until convergence is reached. The direct learning circuit is generally coupled to the amplifier circuit and the indirect learning circuit and that receives the input signal so that the predistortion data can be copied to the direct learning circuit from the indirect learning after convergence is reached and so that the direct learning circuit can adjust the predistortion data during a direct learning mode.
摘要:
An apparatus is provided to determine pre-distortion for a nonlinear system. The apparatus comprises a datapath and a power amplifier. The datapath employs predistortion data to generally linearized the power amplifier. To generate this predistortion data, an indirect learning circuit and a direct learning circuit can be employed. The indirect learning circuit is generally coupled to the amplifier circuit so that it can iteratively adjust predistortion data during an indirect learning mode until convergence is reached. The direct learning circuit is generally coupled to the amplifier circuit and the indirect learning circuit and that receives the input signal so that the predistortion data can be copied to the direct learning circuit from the indirect learning after convergence is reached and so that the direct learning circuit can adjust the predistortion data during a direct learning mode.
摘要:
A method of determining indices for matrix codewords in a matrix codeword codebook. The matrix codewords are adapted for communicating information between a transmitter and a receiver. The method includes retrieving from temporary storage, an eigenmode representation for a communications channel, where the eigenmode representation is based upon on a received signal precoded by a first matrix codeword. The method also includes performing a test on multiple vector codewords to identify a first vector codeword among the multiple vector codewords, where the test includes determining a relationship between the first vector codeword and the representation of an eigenmode. The first vector codeword is associated with a first vector codeword index that identifies the first vector codeword. The method also includes generating a matrix codeword index associated with a second matrix codeword in the matrix codeword codebook. The matrix codeword index is based upon the first vector codeword index, and the order of the first vector codeword is different from the order of the second matrix codeword.
摘要:
A method of determining indicators for matrix codewords in a matrix codeword codebook, where the matrix codewords are adapted for communicating information between a transmitter and a receiver. The method includes providing a lookup table that is associated with multiple codewords that are associated with a codebook. The lookup table has m rows, and each row in the lookup table has a one-to-one correspondence with a codeword in the multiple codewords. Each row has p entries and each of the p entries holds a codeword indicator that identifies a codeword in the multiple codewords. The (i,j)th entry in the lookup table holds the codeword indicator identifying the jth most similar codeword to the codeword associated with the ith row according to a similarity metric, where 1≦i≦m and 1≦j≦p, and the m rows include a row k. The method includes identifying a first indicator in the row k by testing each of the indicators in the first p entries of row k to determine which of the indicators in the first n entries identifies a reduced search codeword that best satisfies a selection criterion, wherein, n has a predetermined value and 1≦n≦p, and, in relation to the other remaining indicators in the first n entries of the first row, the first indicator identifies the reduced search codeword that best satisfies the selection criterion.
摘要:
The adaptive filtering techniques described herein allow a filter that is operating in a target domain to be trained in another domain, possibly with constraints, using the same adaptation framework used in a standard adaptive filter. As a result, the adaptation engine may be configured to run in a transform domain that is more desirable than the target domain. For example, the transform domain may be less susceptible to noise or may have more impact on the trained filter's desired results. The filter is trained in the transform domain and then the filter hardware is updated in the target domain.
摘要:
A method of determining indices for matrix codewords in a matrix codeword codebook. The matrix codewords are adapted for communicating information between a transmitter and a receiver. The method includes retrieving from temporary storage, an eigenmode representation for a communications channel, where the eigenmode representation is based upon on a received signal precoded by a first matrix codeword. The method also includes performing a test on multiple vector codewords to identify a first vector codeword among the multiple vector codewords, where the test includes determining a relationship between the first vector codeword and the representation of an eigenmode. The first vector codeword is associated with a first vector codeword index that identifies the first vector codeword. The method also includes generating a matrix codeword index associated with a second matrix codeword in the matrix codeword codebook. The matrix codeword index is based upon the first vector codeword index, and the order of the first vector codeword is different from the order of the second matrix codeword.
摘要:
An embodiment of the invention provides a method of detecting the position(s) where sensor(s) are activated on an interactive screen using sparse-activation compressive sensing. Sparse-activation compressive sensing makes use of the situation where the number of simultaneously activated sensors is substantially smaller than the number of sensors (nodes). Because the number of simultaneously activated sensors is substantially smaller than the number of sensors, the number of measurements required for determining which sensors are activated may also be reduced. Because fewer measurements are required when compared with full-scan techniques, less circuitry and power is required to detect the location(s) of activated sensors on an interactive screen.