Interdigital Technology Corporation

Interdigital Technology Corpoartion

Parthapratim De

Ariela Zeira

Jung-Lin Pan

Raj Mani Misra

Kyle Jung-Lin Pan

A code division multiple access base station receives K data signals over a shared spectrum. The base station receives and samples a combined signal having the K transmitted data signals. A combined channel response matrix is produced. A block column of a cross correlation matrix is determined using the combined channel response matrix. Each block entry of the block column is a K by K matrix. A fourier transform of a complex conjugate transpose of the combined channel response matrix multiplied to the combined signal samples is taken. An inverse of a fourier transform of each block entry is multiplied to a result of the fourier transform to produce a fourier transform of the data vector. An inverse fourier transform of the data vector fourier transform is taken to produce data of the K signals.

Fast joint detection base station

A transmitter site transmits a plurality of different data signals at a chip rate over a shared spectrum in a code division multiple access communication system. Each transmitted data signal experiences a similar channel response. A combined signal of the transmitted data signals is received. The combined signal is sampled at a multiple of the chip rate. The channel response for the combined signal is determined. A spread data vector is determined using the combined signal samples and the estimated channel response. The data of the different data signals is determined using the spread data vector.

Method and apparatus for receiving plurality of data signals

A method of recovering data for use in a receiver that simultaneously receives a plurality of code division multiple access data signals, each data signal experiencing a similar channel response. A combined signal over the shared spectrum in a time slot is received and sampled. The combined signal comprises the plurality of data signals. The sampled signal is used to estimate the similar channel response, and a channel response matrix is constructed. A channel correlation matrix is constructed based in part on the estimated channel response matrix. A fast Fourier transform (FFT) decomposition of a circulant matrix approximation of the channel correlation matrix, and the sampled data signals, are used to determine a spread data vector. The spread data vector is despread to recover data from the matrix.

Data detection method and receiver

A code division multiple access user equipment receives K data signals over a shared spectrum. The user equipment receives and samples a combined signal having the K transmitted data signals. A combined channel response matrix is produced. A block column of a cross correlation matrix is determined using the combined channel response matrix. Each block entry of the block column is a K by K matrix. Each block entry of the block column is a K by K matrix. A fourier transform of a complex conjugate transpose of the combined channel response matrix multiplied to the combined signal samples is taken. An inverse of a fourier transform of each block entry is multiplied to a result of the fourier transform to produce a fourier transform of the data vector. An inverse fourier transform of the data vector fourier transform is taken to produce data of the K signals.

Fast joint detection user equipment

A transmitter site transmits a plurality of data signals over a shared spectrum in a code division multiple access communication system. Each transmitted data signal experiences a similar channel response. A combined signal of the transmitted data signals is received. The combined signal is sampled at a multiple of the chip rate. The channel response for the combined signal is determined. A first element of a spread data vector is determined using the combined signal samples and the estimated channel response. Using a factor from the first element determination, remaining elements of the spread data vector are determined. The data of the data signals is determined using the determined elements of the spread data vector.

A code division multiple access base station is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated. A cross correlation matrix is determined using the estimated channel response. The spread data vector is determined using order recursions by determining a first spread data estimate using an element from the cross correlation matrix and recursively determining further estimates using additional elements of the cross correlation matrix. Data of the data signals is estimated using the spread data vector.

Single user detection base station

A code division multiple access user equipment is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated. A cross correlation matrix is determined using the estimated channel response. A subblock of the cross correlation matrix is selected. A Cholesky factor for the subblock is determined. The Cholesky factor is extended. The spread data vector is determined using the extended Cholesky factor, a version of the channel response and the samples. Data of the data signals is estimated using the spread data vector.

Single user detection user equipment

A code division multiple access base station is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated. A cross correlation matrix is determined using the estimated channel response. A subblock of the cross correlation matrix is selected. A Cholesky factor for the subblock is determined. The Cholesky factor is extended. The spread data vector is determined using the extended Cholesky factor, a version of the channel response and the samples. Data of the data signals is estimated using the spread data vector.

A code division multiple access base station is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated at the multiple of the chip rate. The multiple chip rate estimated channel response is combined as an effective chip rate channel response. A spread data vector is determined using the effective samples, the effective channel response and a fourier transform. Data of the data signals is estimated using the spread data vector.

A code division multiple access user equipment is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated as a channel response matrix at the multiple of the chip rate. A padded version of a spread data vector of a size corresponding to the multiple chip rate using a column of the channel response matrix, the estimated channel response matrix, the samples and a fourier transform. The spread data vector is estimated by eliminating elements of the padded version so that the estimated spread data vector is of a size corresponding to the chip rate.

A code division multiple access user equipment is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated. A cross correlation matrix is determined using the estimated channel response. The spread data vector is determined using order recursions by determining a first spread data estimate using an element from the cross correlation matrix and recursively determining further estimates using additional elements of the cross correlation matrix. Data of the data signals is estimated using the spread data vector.

A code division multiple access user equipment is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated at the multiple of the chip rate. The multiple chip rate estimated channel response is combined as an effective chip rate channel response. A spread data vector is determined using the effective samples, the effective channel response and a fourier transform. Data of the data signals is estimated using the spread data vector.

Single user detection

A code division multiple access base station is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over a shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated. A first element of a spread data vector is determined using the combined signal samples and the estimated channel response. A factor from the first element determination is used to determine remaining elements of the spread data vector. Data of the data signals is estimated using the determined elements of the spread data vector.

A code division multiple access base station is used in receiving a plurality of data signals over a shared spectrum. Each received data signal experiences a similar channel response. A combined signal of the received data signals is received over the shared spectrum. The combined signal is sampled at a multiple of the chip rate. A channel response is estimated as a channel response matrix at the multiple of the chip rate. A padded version of a spread data vector of a size corresponding to the multiple chip rate using a column of the channel response matrix, the estimated channel response matrix, the samples and a fourier transform. The spread data vector is estimated by eliminating elements of the padded version so that the estimated spread data vector is of a size corresponding to the chip rate.

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Parthapratim De