摘要:
A memory control unit of a turbo code decoder includes a buffer having a plurality of storage slots, a buffer control operatively coupled to the buffer, a router operatively coupled to the buffer control and to a plurality of data sources, and a conflict detection unit operatively coupled to the router, to the buffer control, and to the plurality of data sources. The buffer temporarily stores information intended for storage in a memory bank. The buffer control determines a number of available storage slots in the buffer. The router routes data from the data sources to the buffer control. The conflict detection unit initiates a temporary halt of some of the data sources when the number of available storage slots is insufficient to store all of the data from data sources attempting to access the memory bank.
摘要:
A memory control unit of a turbo code decoder includes a buffer having a plurality of storage slots, a buffer control operatively coupled to the buffer, a router operatively coupled to the buffer control and to a plurality of data sources, and a conflict detection unit operatively coupled to the router, to the buffer control, and to the plurality of data sources. The buffer temporarily stores information intended for storage in a memory bank. The buffer control determines a number of available storage slots in the buffer. The router routes data from the data sources to the buffer control. The conflict detection unit initiates a temporary halt of some of the data sources when the number of available storage slots is insufficient to store all of the data from data sources attempting to access the memory bank.
摘要:
A wireless receiver is constructed to equalize a time-domain received signal, detect a plurality of symbols of the equalized time-domain received signal, and perform interference cancellation on the time-domain received signal. The interference cancellation can be performed using a partial result produced by an IDFT, and may use only neighboring symbols in a detected plurality of symbols. The resulting wireless receiver can be constructed to operate efficiently under a plurality of wireless standards.
摘要:
Disclosed is a LMMSE receiver that restores orthogonality of spreading codes in the downlink channel for a spread spectrum signal received over N receive antennas. The FFT-based chip equalizer tap solver reduces the direct matrix inverse of the prior art to the inverse of some submatrices of size N×N with the dimension of the receive antennas, and most efficiently reduces matrix inverses to no larger than 2×2. Complexity is further reduced over a conventional Fast Fourier Transform approach by Hermitian optimization to the inverse of submatrices and tree pruning. For a receiver with N=4 or N=2 with double oversampling, the resulting 4×4 matrices are partitioned into 2×2 block sub-matrices, inverted, and rebuilt into a 4×4 matrix. Common computations are found and repeated computations are eliminated to improve efficiency. Generic design architecture is derived from the special design blocks to eliminate redundancies in complex operations. Optimally, the architecture is parallel and pipelined.
摘要:
A system, apparatus and method for a multi-stage Parallel Residue Compensation (PRC) receiver for enhanced suppression of the Multiple Access Interference (MAI) in Code Division Multiple Access (CDMA) systems. The accuracy of the interference estimation is improved with a set of weights computed from an adaptive Normalized Least Mean Square (NLMS) algorithm. In order to reduce complexity, the commonality of the multi-code processing is extracted and used to derive a structure of PRC to avoid direct interference cancellation. The derived PRC structure reduces the interference cancellation architecture from a complexity that is proportional to the square of the number of users to a complexity that is linear with respect to the number of users. The complexity is further reduced by replacing dedicated multiplier circuits with simple combinational logic.
摘要:
A wireless receiver is constructed to equalize a time-domain received signal, detect a plurality of symbols of the equalized time-domain received signal, and perform interference cancellation on the time-domain received signal. The interference cancellation can be performed using a partial result produced by an IDFT, and may use only neighboring symbols in a detected plurality of symbols. The resulting wireless receiver can be constructed to operate efficiently under a plurality of wireless standards.
摘要:
An apparatus for trellis-based detection in a communication system including a processor and memory having computer program code configured to construct a trellis representing a transmitted signal formed from a plurality of symbols, each having a constellation size, transmitted by a number of transmit antennas, and form a log likelihood ratio at nodes of the trellis as a log-sum of a number of exponential terms corresponding to a hypothesized transmitted bit value of the plurality of symbols. The number of exponential terms is limited by a number of most likely paths of the trellis extending from each node of the trellis and the constellation size. The processor and memory including computer program code are further configured to form a list at each node of the trellis of a size limited to the number of the most likely paths of the trellis extending from each node of the trellis.
摘要:
An apparatus for trellis-based detection in a communication system including a processor and memory having computer program code configured to construct a trellis representing a transmitted signal formed from a plurality of symbols, each having a constellation size, transmitted by a number of transmit antennas, and form a log likelihood ratio at nodes of the trellis as a log-sum of a number of exponential terms including a priori information corresponding to a hypothesized transmitted bit value of the plurality of symbols. The number of exponential terms is limited by a number of most likely paths of the trellis extending from each node of the trellis and the constellation size. The processor and memory including computer program code are configured to form a list at each node of the trellis of a size limited to the number of the most likely paths of the trellis extending from each node.
摘要:
An apparatus for trellis-based detection in a communication system including a processor and memory having computer program code configured to construct a trellis representing a transmitted signal formed from a plurality of symbols, each having a constellation size, transmitted by a number of transmit antennas, and form a log likelihood ratio at nodes of the trellis as a log-sum of a number of exponential terms including a priori information corresponding to a hypothesized transmitted bit value of the plurality of symbols. The number of exponential terms is limited by a number of most likely paths of the trellis extending from each node of the trellis and the constellation size. The processor and memory including computer program code are configured to form a list at each node of the trellis of a size limited to the number of the most likely paths of the trellis extending from each node.
摘要:
Methods and apparatuses are provided for MIMO detection. A method may include considering a symbol vector received over MIMO system. The method may further include generating a list comprising a predefined number of candidate transmit symbol vectors based at least in part upon the received symbol vector using a trellis comprising a plurality of nodes that apply distributed list decoding to generate the list, wherein the list of the predefined number of candidate transmit symbol vectors comprises the predefined number of candidate transmit symbol vectors derived from the set of all possible trellis paths as determined based at least in part upon the respective cumulative trellis path weights. Corresponding apparatuses are also provided.