摘要:
Automatic gain control in a receiver. A method for controlling operating range of an analog-to-digital converter (ADC) by an automatic gain control circuit includes estimating a peak-to-average ratio corresponding to an analog signal from digital samples of the analog signal. The method includes determining a peak value corresponding to the analog signal based on the peak-to-average ratio. Further, the method includes maintaining magnitude of the analog signal at an input of the ADC and gain of the receiver based on the peak value.
摘要:
Automatic gain control in a receiver. A method for controlling operating range of an analog-to-digital converter (ADC) by an automatic gain control circuit includes estimating a peak-to-average ratio corresponding to an analog signal from digital samples of the analog signal. The method includes determining a peak value corresponding to the analog signal based on the peak-to-average ratio. Further, the method includes maintaining magnitude of the analog signal at an input of the ADC and gain of the receiver based on the peak value.
摘要:
A wireless device receives an input signal representing a signal of interest (e.g., one or more portions of a packet) on a wireless medium. The input signal may, in addition, contain narrowband interference signals. The wireless device removes the signal of interest from the input signal to produce a residue signal, and analyzes the residue signal to determine the presence of any interference bands in which narrowband interference signals may be present. The wireless device then removes the detected interference bands from the input signal. The residue signal may reveal the presence of interference signals, which might otherwise be hard to distinguish in the input signal. Thus, interference signals with power levels much lower than the power of the signal of interest may be detected and removed.
摘要:
A wireless receiver operating in a wireless communication environment in which a beginning of a packet contains a repetitive sequence. The wireless receiver may compute a variance (example of a measure of variations in the cross correlation values) of cross-correlation values obtained by cross correlating a received signal and a copy of the preamble sequence starting at different time instances. When a valid packet is received, the variance of the values resulting from the cross correlation is high, otherwise the variance is low. As a result packet detection is made robust, and false packet detection due to interference signals is reduced. In an embodiment, the wireless receiver is implemented in the context of WLAN 802.11 a/g network.
摘要:
An aspect of the present invention provides signal quality information representing the angular deviations (i.e., based on the phase angle difference between the received symbol and the corresponding decoded symbol (i.e., selected symbol point in a signal constellation)). As a result, a relatively more accurate signal quality information is provided to external component at least in systems in which the signal constellation do not have multiple symbols in the same angle. The computational complexity may also be reduced as a result.
摘要:
Apparatus and methods disclosed herein perform gain, clipping, and phase compensation in the presence of I/Q mismatch in quadrature RF receivers. Gain and phase mismatch are exacerbated by differences in clipping between I & Q signals in low resolution ADCs. Signals in the stronger channel arm are clipped differentially more than weaker signals in the other channel arm. Embodiments herein perform clipping operations during iterations of gain mismatch calculations in order to balance clipping between the I and Q channel arms. Gain compensation coefficients are iteratively converged, clipping levels are established, and data flowing through the network is gain and clipping compensated. A compensation phase angle and phase compensation coefficients are then determined from gain and clipping compensated sample data. The resulting phase compensation coefficients are applied to the gain and clipping corrected receiver data to yield a gain, clipping, and phase compensated data stream.
摘要:
Dual band wireless local area network (WLAN) transceiver. A wireless communication device includes at least two different transceivers (or radios) therein to effectuate communications with other wireless communication devices using at least two respective frequency bands. Each of these two transceivers may have different respective circuitry (e.g., each may have a different respective power amplifier (PA) and/or other circuitry components). Coordination is made regarding when certain components of one transceiver turn on and operate when another transceiver may be transmitting or receiving communications. For example, the turn on of a PA and/or other circuitry components (e.g., such as components using or requiring high current) within one transceiver can be coordinated as to minimize deleterious effects regarding the operation of another transceiver. Moreover, latency existent within each of the respective transceiver chains within the wireless communication device (e.g., including baseband and radio portions) is accounted for regarding their respective concurrent operation.
摘要:
A wireless receiver for multiple frequency bands reception includes a single receive radio frequency (RF) circuit (160, 170) having an RF bandpass substantially confined to encompass at least two non-overlapped such frequency bands at RF, a single in-phase and quadrature (approximately I, Q) pair of intermediate frequency (IF) sections (120I, 120Q) having an IF passband, and a mixer circuit (110) including an in-phase and quadrature (I,Q) pair of mixers (110I, 110Q) fed by said RF circuit (160, 170) and having a local oscillator (100) with in-phase and quadrature outputs coupled to said mixers (110I, 110Q) respectively, said mixer circuit (110) operable to inject and substantially overlap the at least two non-overlapped frequency bands with each other into the IQ IF sections (120I, 120Q) in the IF passband, the IF passband substantially confined to a bandwidth encompassing the thereby-overlapped frequency bands. Other receivers, circuits.
摘要:
Apparatus and methods disclosed herein perform gain, clipping, and phase compensation in the presence of I/Q mismatch in quadrature RF receivers. Gain and phase mismatch are exacerbated by differences in clipping between I & Q signals in low resolution ADCs. Signals in the stronger channel arm are clipped differentially more than weaker signals in the other channel arm. Embodiments herein perform clipping operations during iterations of gain mismatch calculations in order to balance clipping between the I and Q channel arms. Gain compensation coefficients are iteratively converged, clipping levels are established, and data flowing through the network is gain and clipping compensated. A compensation phase angle and phase compensation coefficients are then determined from gain and clipping compensated sample data. The resulting phase compensation coefficients are applied to the gain and clipping corrected receiver data to yield a gain, clipping, and phase compensated data stream.
摘要:
Method and system for false lock free autonomous scan in a receiver is disclosed. The method includes identifying a presence of a desired signal to avoid false frequency lock in a Frequency Modulation receiver. The method includes receiving a signal. The method further includes identifying the desired signal, if a first energy is above a first threshold. The method also includes identifying the desired signal, if an Intermediate Frequency count is below a second threshold. The method includes identifying the desired signal, if a second energy of the signal is above a third threshold. The method includes identifying the desired signal, if an absolute difference between a first Received Signal Strength Indication (RSSI) value and a second RSSI value of the signal is below a fourth threshold. The method includes determining a third energy. The method includes identifying the desired signal, if the third energy is below a fifth threshold.