摘要:
A method for collision avoidance in multiple protocol networks using a shared communication medium begins by determining a first protocol probable active time period. The method continues by determining a first protocol probable inactive time period. The method continues by generating a transmit blocking indication based on the first protocol probable active time period and the first protocol probable inactive time period.
摘要:
A Finite Impulse Response (FIR) filter is implemented in software on a general purpose processor in a manner which reduces the number of memory accesses as compared to conventional methods. In particular, an efficient implementation for a general purpose processor having a substantial number of registers includes inner and outer loop code which together make K [ ( L 1 + L 2 L 1 L 2 ) N + L 2 L 1 + 1 ] memory accesses and KN multiply-accumulates, where L1 is the number of output vector elements computed during each pass through the outer loop and where L2 is the number of taps per output vector element computed during each pass through the inner loop. The efficient implementation exploits L1+2L2 general purpose registers. For an embodiment in which L1=L2=8, inner and outer loop code make K ( N 4 + 2 ) memory accesses, which for filter implementations with large numbers of taps, approaches a 4× reduction in the number of memory accesses as compared to conventional methods.
摘要:
Aspects of a method and system for compensating for estimated distortion in a transmitter by utilizing a digital predistortion scheme with a quadrature feedback mixer configuration are presented. Aspects of the system may include an RF transmitter that enables generation of an RF output signal in response to one or more generated input signals. A one or more feedback signals may be generated by performing frequency downconversion on the RF output signal within a corresponding one or more feedback mixer circuits. The generated one or more feedback signals may be inserted at a corresponding one or more insertion points in an RF receiver. Each insertion point may be between a receiver mixer circuit and corresponding circuits that generate a baseband signal based on the corresponding one of the feedback signals.
摘要:
A filter is implemented in software on a general purpose processor in a manner which reduces the number of memory accesses as compared to conventional methods. In some realizations, both application code and filter code are executed on a same general purpose processor. The filter code incrementally loads respective portions of input and coefficient vector data from addressable storage into respective registers of the processor and performs successive operations thereupon to accumulate output vector data into other respective registers of the processor. The filter code typically exhibits an execution ratio of less than two input and coefficient data loads per operation to accumulate. In some realizations, the filter code is callable from the application code and provides the application code with a signal processing facility without use of a digital signal processor (DSP).
摘要:
A reduced state maximum likelihood sequence estimator allows the use of improved equalization techniques that provides greatly improved performance for channels with severe attenuation and spectral nulls. The reduced state maximum likelihood sequence estimator retains kn states of a total number of K states, kn
摘要:
A phase-splitting T/3 equalizer and echo canceller structure is computationally efficient because only one point per baud is calculated. However, there are two drawbacks to the structure: (1) since the equalizer performs both the phase-splitting function and channel response equalization, its convergence is slow, and (2) when training the echo canceller during half-duplex training, an answering modem needs an assumed equalizer in its receive path to train its echo canceller, because the adaptive equalizer has not yet been trained; however, after equalizer training the echo canceller needs to be retrained because equalizer coefficients have changed. In contrast, a fixed phase splitting filter can be used during training. The echo canceller and equalizer are each trained with the fixed phase splitting filter thereby improving convergence performance, and after training, the equalizer is convolved with the fixed phase splitting filter to provide the combined phase splitting equalizer and the equalizer is convolved with the echo canceller to provide the combined echo canceller. In this way, computational load is small in steady state and convergence is fast during training. Even though the convergence rate is slower in data mode, it suitable for tracking line variations. An advantage of the transformation from the training structure to the steady-state structure is that a modem or system exploiting the technique provides improved convergence during training while reducing computational load during full-duplex operations. Half-duplex applications, i.e., modem or system operations without echo cancellation, similarly benefit from improved convergence during training and reduced computational load during steady-state operations.
摘要:
A technique to provide a WLAN-based positioning system to determine a location of a mobile wireless receiving device. A single access point is used to generate a plurality of beacons, in which each beacon of the plurality of beacons has a unique identifier. Each beacon is then transmitted in a different direction from other beacons. When the receiving device receives at least one of the transmitted beacons, signal strength or some other signal parameter is obtained from the at least one received beacon. The received signal parameter is used to determine the location of the mobile receiving device.
摘要:
A wireless access point (AP) radio may be integrated in a cable. The cable may comprise one or more other integrated wireless AP radios. The cable may be communicatively coupled to a wireless controller and the wireless AP radio may receive power from the wireless controller via the cable. Feature information and/or configuration parameter settings may be received by the wireless AP radio from the wireless controller via the cable. The wireless AP radio may provide wireless communication services such as wireless access to a wired network for one or more client devices, based on the feature information and/or the configuration parameter settings. When one or more adjacent wireless AP radios in the cable become non-operational, the wireless AP radio may increase its transmission power to increase its coverage for covering at least a portion of coverage area associated with the one or more non-operational adjacent wireless AP radios.
摘要:
A wireless device includes at least one antenna, an RF interface, and processing circuitry coupled to the RF interface and indirectly to the at least one antenna. The wireless device identifies other wireless devices that service based upon transmission characteristics of wireless signals received from other wireless devices and/or relative positions of the other wireless devices with respect to itself. In a first operational period, the wireless device determines transmission characteristics of the other wireless devices. Then, during a second operational period, without further interaction with the other wireless devices, the wireless device determines communication link characteristics based simply upon transmission characteristics of the other wireless devices.
摘要:
A method for processing signals in a receiver includes receiving a plurality of wireless signals via a plurality of M receive antennas coupled to M corresponding signal amplifiers. The method may also include measuring corresponding signal strengths of M signals generated when each of M phase-shifters is coupled to each of the M receive antennas, while one or more of the M signal amplifiers are disabled. One of the M generated signals may be selected for processing without the use of an antenna switch, where the selecting may be based on the measured signal strength. Each of the plurality of received wireless signals may be amplified prior to the measuring. One or both of an in-phase (I) component and/or a quadrature (Q) component may be generated for each of the M generated signals.