Abstract: A control of an amplifier in an automatic gain control (AGC) loop, e.g. in the RF front end circuitry of an OFDM receiver, provides phase adjustment control data to an associated automatic frequency control (AFC), to compensate for a phase jump that would otherwise be caused by switching of the AGC gain between discrete gain states. In the disclosed example, for each gain state, comparators detect a signal energy estimate crossing either a high threshold or a low threshold. Upon threshold crossing, multiplexers select compensation data corresponding to the necessary transition from the prior state to the new state determined by the comparators, based on identification of the prior state and on the particular threshold that has been crossed (high or low). The phase compensation data supplied to the AFC, for one interval corresponding to the timing of the gain switching, adjusts phase rotation implemented in the AFC.

Abstract: Systems and methods are provided for enhancing signal quality at receivers in a wireless network. In one embodiment, an antenna is selected from a subset of antennas based on a signal quality parameter such as received signal power or signal-to-noise ratio (SNR). In another embodiment, multiple antennas are applied to independent signal processing paths for the respective antennas where output from the paths is then combined to enhance overall signal quality at the receiver.

Abstract: Systems and methods are provided for enhancing signal quality at receivers in a wireless network. In one embodiment, an antenna is selected from a subset of antennas based on a signal quality parameter such as received signal power or signal-to-noise ratio (SNR). In another embodiment, multiple antennas are applied to independent signal processing paths for the respective antennas where output from the paths is then combined to enhance overall signal quality at the receiver.

Abstract: Systems and methodologies are described that facilitate monitoring RF channels in a wireless communication environment to determine whether one or more channels comprise a forward-link-only (FLO) signal. A receiver can receive a first RF channel with a FLO signal and can monitor other RF channels for FLO signals. Upon a determination that a monitored RF channel comprises a FLO signal, the receiver can switch between the first RF channel and the monitored RF channel to facilitate providing seamless reception of the FLO signal, which can be superframe synchronized between RF channels. FLO signal detection can be performed using one or more of a wide-area identification channel energy detection protocol and a wide-area overhead information symbol decoding error detection protocol.

Abstract: Time filtering channel estimates in a wireless communication system, such as an Orthogonal Frequency Division Multiplex (OFDM) system, can be used to improve the quality of channel estimates. The characteristics of an optimal channel estimate time filter can depend on the manner in which the channel estimate is determined as well as the time correlation of channel estimates. A receiver can implement an adaptive time filter for channel estimates in which the time filter response can vary based on channel estimate parameters. The channel estimate parameters can include the manner of determining channel estimates, a time correlation of channel estimates, and an estimated Doppler frequency. The time filter response can be varied continuously over a range of responses or can be varied discretely over a predetermined number of time filter responses.

Abstract: Techniques for performing automatic gain control (AGC) at a wireless receiver are described. The total gain for the wireless receiver is achieved with discrete gain steps for analog circuitry and continuous gain for a digital variable gain amplifier (DVGA). An AGC loop is updated based on power measurements for an output signal from the DVGA. A first gain for the analog circuitry is selected from among multiple discrete gain values based on the AGC loop to maintain the average power of a baseband signal within a predetermined range at an analog-to-digital converter (ADC) input. A second gain for the DVGA is selected based on the AGC loop to maintain the average power of the output signal at a reference power level. The first gain is switched in a manner to avoid saturation of the ADC caused by the baseband signal and to provide switching hysteresis. The AGC may be performed in log domain and with multiple modes.

Abstract: Systems and methods are provided for tracking and compensating for analog gain mismatches or changes in a receiver. In an embodiment, a method is provided to track analog gain step magnitudes during operation of a device. The method includes employing an error signal between an automatic gain control (AGC) output and a reference level as input to a gain step magnitude tracking component. This also includes determining at least one compensation value from the AGC output to update a nominal gain step magnitude that tracks an actual gain step magnitude.