摘要:
Devices, methods, and other embodiments associated with phase based preamble detection are described. In one embodiment, an apparatus includes a wireless transceiver, an evaluation logic, and a configuration logic. The wireless transceiver receives a wireless signal from a wireless device. The wireless signal includes a preamble sequence. The evaluation logic evaluates the preamble sequence by comparing phases of the preamble sequence to phases of predefined preamble sequences to identify a matching preamble sequence. The comparison is done without using amplitude information. The configuration logic configures the wireless transceiver to synchronize wireless communications with the wireless device based, at least in part, on the matching preamble sequence.
摘要:
In accordance with the teachings described herein, systems and methods are provided for calibrating DC offset in a receiver. A DC calibration circuit may be used that is configured to remove DC offset from a digital multi-carrier modulated (MCM) signal that includes a sequence of MCM symbols. The DC calibration circuit may include an accumulator and a compensator. The accumulator may be used to determine an estimated DC offset of a current MCM symbol in the sequence of MCM symbols. The compensator may be used to remove the estimated DC offset from a next MCM symbol in the sequence of MCM symbols. The accumulator may also be used to receive a plurality of digital samples that comprise the current MCM symbol and to determine the estimated DC offset by calculating an average of the plurality of digital samples.
摘要:
In a method for synchronizing a receiver to a synchronous signal, in a signal having been processed based on an automatic gain control (AGC) with a varying gain, a symbol is detected. An estimated beginning of a subsequent frame is determined based on the detected symbol. A gain of the AGC is fixed for a period during which the estimated start of the subsequent frame is processed by the AGC. A transform of the signal is analyzed to determine if the estimated start of the subsequent frame corresponds to an actual start of the subsequent frame. If the estimated start of the subsequent frame does not corresponds to the actual start of the subsequent frame, the gain of the AGC is allowed to resume varying and, a further symbol in the signal is detected, the signal having been processed based on the varying gain of the AGC.
摘要:
In accordance with the teachings described herein, systems and methods are provided for calibrating DC offset in a receiver. A DC calibration circuit may be used that is configured to receive a digital multi-carrier modulated (MCM) signal that includes a sequence of MCM symbols. The DC calibration circuit may include an accumulator and a compensator. The accumulator may be used to determine an estimated DC offset of a current MCM symbol in the sequence of MCM symbols. The compensator may be used to remove the estimated DC offset from a next MCM symbol in the sequence of MCM symbols. The accumulator may also be used to receive a plurality of digital samples that comprise the current MCM symbol and to determine the estimated DC offset by calculating an average of the plurality of digital samples.
摘要:
In a method for synchronizing a receiver to a synchronous signal, in a signal having been processed based on an automatic gain control (AGC) with a varying gain, a symbol is detected. An estimated beginning of a subsequent frame is determined based on the detected symbol. A gain of the AGC is fixed for a period during which the estimated start of the subsequent frame is processed by the AGC. A transform of the signal is analyzed to determine if the estimated start of the subsequent frame corresponds to an actual start of the subsequent frame. If the estimated start of the subsequent frame does not corresponds to the actual start of the subsequent frame, the gain of the AGC is allowed to resume varying and, a further symbol in the signal is detected, the signal having been processed based on the varying gain of the AGC.
摘要:
In a method for synchronizing a receiver to a synchronous signal, a plurality of potential symbols are detected in a signal, the signal having been processed based on automatic gain control (AGC) with a varying gain. Next frame potential symbols corresponding to potential symbols in the plurality of potential symbols are determined, the next frame potential symbols being in frames subsequent to the frames in which the corresponding potential symbols are located. A gain of the AGC is fixed for each corresponding symbol interval during which a next frame potential symbol is operated on by the AGC. In between next frame potential symbols, the AGC is allowed to vary. Next frame potential symbols are analyzed after a transform is calculated to determine if any correspond to a start of a frame.
摘要:
Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where a receiver has received one or more signal vectors from the same transmitted vector. The receiver processes these received signal vectors one by one, and uses information from signal vectors that have already been processed to process the next signal vector. To process a current signal vector, the receiver concatenates the current signal vector with a previously processed signal vector. This concatenated signal vector is decoded using, for example, a maximum-likelihood (ML). To decode the concatenated signal vector, the ML decoder can use a concatenated channel matrix that includes a channel response matrix associated with the current signal vector and a processed version of previous channel response matrices.
摘要:
Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where the receiver has received one or more signal vectors from the same transmitted vector. The symbols of the received signal vectors are combined, forming a combined received signal vector that may be treated as a single received signal vector. The combined signal vector is then decoded using a maximum-likelihood decoder. In some embodiments, the combined received signal vector may be processed prior to decoding. Systems and methods are also provided for computing soft information from a combined signal vector based on a decoding metric. Computationally intensive calculations can be extracted from the critical path and implemented in preprocessors and/or postprocessors.
摘要:
Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where the receiver has received one or more signal vectors from the same transmitted vector. The symbols of the received signal vectors are combined, forming a combined received signal vector that may be treated as a single received signal vector. The combined signal vector is then decoded using a maximum-likelihood decoder. In some embodiments, the combined received signal vector may be processed prior to decoding. Systems and methods are also provided for computing soft information from a combined signal vector based on a decoding metric. Computationally intensive calculations can be extracted from the critical path and implemented in preprocessors and/or postprocessors.
摘要:
Systems and methods for detecting data in a multiple input/multiple output signal. The method includes receiving a first signal associated with a first data value and a second signal associated with a second data value. A distance value between the received second signal and each possible second data value is calculated. Coordinates for a hypothetical first signal in light of a first possible second data value are calculated, and the first coordinate value is quantized to a nearest constellation point. A distance value between the received second signal and each possible second data value is calculated using the calculated constellation points. A determination is made of a log-likelihood ratio based on the determined distance values.