Abstract: A system and method for stabilizing a coefficient set used by a digital predistortion (DPD) engine to apply pre-distortion to a transmit signal and cancel distortion generated by a distorting element or distorting system when transmitting the transmit signal, including obtaining an initial coefficient set; rotating the initial coefficient set to maintain a phase of fundamental components (w10(t), . . . , w1Q(t)) of the initial coefficient set as a constant value; averaging in the time domain the rotated coefficient set to obtain an averaged coefficient set; applying the averaged coefficient set to the DPD engine, the initial coefficient set expressed in a first equation [27]; computing the phase of the fundamental components of the initial coefficient set with a second equation [28]; and computing the rotated coefficient set with a third equation [29].

Abstract: A method and apparatus for receiving data in a communication system is disclosed. Receiving a first signal from a transmitter, a first canceller cancels from the received first signal a second signal desired to be received from the transmitter. A second canceller detects and cancels an interference signal from the second signal-canceled first signal. A calculator calculates a Log Likelihood Ratio (LLR) of the interference signal-canceled first signal.

Abstract: A method of performing receive antenna selection is presented. The method executes a determination operation for a set of receive antennas, determines a maximum result of the determination operation for two of the antennas, eliminates one of the two antennas from the set of antennas, and repeats the determination and elimination process until only a predetermined number of antennas remain in the set. The signals from these remaining antennas are then processed. The present invention reduces receiver complexity and cost.

Abstract: A wireless modem and noise cancellation method for the same for noise cancellation effectively cancels a noise signal induced from a device to which the wireless modem is connected. A primary antenna receives a radio signal that includes a first noise signal coming from a device to which the wireless modem is connected; a secondary antenna receives a second noise signal from the connected device; a noise signal adjuster for adjusting the second noise signal received by the secondary antenna using a correlation parameter between noise signals received by the primary antenna and the secondary antenna; and a noise remover subtracts the noise signal adjusted by the noise signal adjuster from the radio signal received by the primary antenna.

Abstract: A method of maintaining signal convergence of a transmitter and a receiver of an adaptive differential pulse code modulated (ADPCM) communication system during discontinuous transmission, by generating synchronized comfort noise frame in the transmitter and in the receiver during quiet periods and mutually updating the receiver's decoder and encoder on their states.

Abstract: A transmitter includes a polar modulator that creates phase and amplitude signals which in turn drive a power amplifier. To compensate for AM to PM conversion of the amplitude signal into the amplified signal, a compensation signal is generated from the amplitude signal and combined with the phase signal such that when amplified, the compensation signal cancels the AM to PM conversion. The compensation signal may have an offset term, a linear term, a quadratic term, and a cubic term. A second embodiment comprises a technique by which AM to AM conversion may concurrently be addressed using a second compensation signal.

Abstract: A method and computer program product for operating a linearizer for a circuit, including generating a set of coefficients via a characterizer; predistorting a signal input to the circuit responsive to the coefficients and generating a linearized output in response thereto; filtering the signal through a linear digital filter having linear digital filter taps, each tap other than a first tap being successively delayed by one delay unit; generating powers of the signal; inputting the generated powers of the signal through tapped delay lines, each line having nonlinear digital filter taps, each tap other than a first tap being successively delayed by one delay unit; applying the coefficients to the linear and nonlinear digital filter taps; summing each of the nonlinear digital filter taps corresponding to a certain number of delay units; and adding the sum of each of the delay units to a particular linear digital filter tap.

Abstract: This disclosure describes residual coding techniques that use vector quantization coding, which relies on template matching. However, rather than transmit vector quantization codebook indexes (or codewords) that may have no meaning to standard compliant CODECs, the techniques described herein map the residual templates to pre-computed compressed residual blocks that are compliant with a video standard. The standard compliant compressed residual blocks can then be transmitted to another device, which complies with the standard. The techniques can exploit the advantages associated with vector quantization coding, such as the ability to perform more parallel processing, while still maintaining compliance with a video coding standard.

Abstract: A communication system in which a signal is transferred includes a transmitter that transmits a signal, a receiver that receives a signal transmitted thereto, and an adaptive equalizer that generates a compensated signal by compensating degradation of the signal to be received by the receiver. The adaptive equalizer includes a signal compensating section that generates the compensated signal by passing therethrough the signal to be received by the receiver, a jitter measuring section that measures jitter of the compensated signal output from the signal compensating section, and an adjusting section that adjusts a characteristic of the signal compensating section so as to reduce the jitter of the compensated signal which is measured by the jitter measuring section.

Abstract: A pulse pattern generator (11) has a pulse generating unit (12) and a lowpass filter (14), and the pulse generating unit (12) includes an amplitude-value setting unit (13, 13a). The pulse generating unit (12) generates a pulse signal formed in a step-like wave in which at least one of rise and fall of a signal is changed in a step-like manner. The lowpass filter (14) smoothes the pulse signal generated by the pulse generating unit (11), and outputs a smoothed pulse signal. The amplitude-value setting unit (13, 13a) adjusts an amplitude value of a step-like wave that forms the pulse signal in order to set a shape of an eye waveform based on a setting value when an eye pattern of the output from the lowpass filter (14) is formed. The pulse pattern generator (11) can output the pulse signal having a desired pulse pattern having the predetermined eye closure from the lowpass filter (14).

Abstract: A wireless transmitter is configured to map N first samples of a first discrete Fourier transform (DFT) of a group of coded symbols to M sub-carriers according to a first sub-carrier mapping rule. In this case, M is greater than N. The wireless transmitter is also configure to perform a first inverse DFT (IDFT) on the M sub-carriers to provide M second samples and clip the M second samples according to a clipping rule to provide M third samples. The wireless transmitter is further configured to perform a second DFT on the M third samples, de-map the M third samples to N fourth samples, and map the N fourth samples to O subcarriers according to a predetermined second subcarrier mapping rule. In this case, O is greater than or equal to M.

Abstract: Disclosed is a method and apparatus for transmitting data in a cellular communication system including at least one base station that communicates with a plurality of mobile stations through a given frequency band. The method and apparatus divides the frequency band into at least two subcarrier groups each including a plurality of subcarriers; allocates at least one subcarrier group to each mobile station, and changes the subcarrier group allocated to each mobile station according to a predetermined period; and codes data to be transmitted to each mobile station with a plurality of codes, and transmits modulation symbols obtained by performing inverse fast Fourier transform (IFFT) on a plurality of subcarriers of the allocated subcarrier group.

Abstract: Communication systems are described that use signal constellations, which have unequally spaced (i.e. ‘geometrically’ shaped) points. In many embodiments, the communication systems use specific geometric constellations that are capacity optimized at a specific SNR. In addition, ranges within which the constellation points of a capacity optimized constellation can be perturbed and are still likely to achieve a given percentage of the optimal capacity increase compared to a constellation that maximizes dmin, are also described. Capacity measures that are used in the selection of the location of constellation points include, but are not limited to, parallel decode (PD) capacity and joint capacity.

Abstract: Processing a coded signal formed so that multiple signal points, having individual signal values consonant with coded values, are arranged in accordance with a predetermined order. A signal restoration unit calculates an average value for signal values at signal points immediately preceding and following a predetermined signal point. The predetermined signal point comprises the coded signal. The signal restoration unit calculates, for selected preceding signal points, a signal value difference for the two selected signal points, and obtains first difference values. The signal restoration unit calculates, for selected following signal points, a signal value difference for the two selected signal points, and obtains second difference values. The signal restoration unit corrects the average value by employing either one or a plurality of either the first or the second, or both first and second difference values to obtain a restored value for a signal value at the predetermined signal point.

Abstract: A predistortion linearized amplifier system that uses analog polynomial based predistortion is disclosed. An analog polynomial function generator receives polynomial parameter updates from a polynomial parameter generator. The polynomial parameter generator uses a combination of analog and digital signal processing to create the parameter updates. This processing is performed on input signal amplitude, detected using analog circuits, and RF coupled samples of the input signal, and the output signal. By using a combination of analog and digital signal processing means, digital processing can be performed at sub-Nyquist rates, significantly reducing the cost of digital circuits. Also, since the predistortion modulation signal is created with an analog function generator, time correlating delay is minimized reducing circuit costs.

Abstract: A prediction signal calculator with a limit function is provided with a multiplier calculating a partial prediction signal composed of the product of a polar prediction coefficient for generating a regenerative signal and a quantized regenerative signal, a display conversion section for converting the partial prediction signal from floating point representation to an absolute value display, and a limiter executing processing for substituting limit values in the partial prediction signal satisfying overflow conditions during conversion of the partial prediction signal from floating point representation to an absolute value display in the event that the error detector determines that there are code errors in the audio data for a predetermined number of frames of the audio data.

Abstract: A power amplifier pre-distorter is formed by a FIR filter structure that includes an individual look-up table for each filter tap, where each look-up table represents a sampled polynomial in a variable representing signal amplitude. An absolute value block selects, from each filter tap look-up table, a filter coefficient that depends on the amplitude of a corresponding complex signal value to be multiplied by the filter tap. This structure can pre-distort both for amplitude distortion and memory effects in the power amplifier.

Abstract: A receiver suppresses noise simultaneously using a noise suppressor and an automatic gain controller (AGC). The receiver divides a received signal into an audio period and a non-audio period, analyzes whether the noise characteristic of the non-audio period corresponds to a non-static noise or a static noise, and if the noise characteristic corresponds to the static noise, analyzes whether the static noise is caused by a network or a transmitter side terminal. In accordance with the analyzed noise characteristic, the noise suppressor firstly suppresses the noise by determining the noise suppressing intensity, and sends a signal, from which the noise has been firstly suppressed, to the AGC. The AGC secondly suppresses the noise included in the signal. In this case, the threshold value of the AGC is controlled in real time in accordance with the noise characteristic.

Abstract: A digital adaptive predistorter look up table (DAPD-LUT) technique dynamically adapts a look up table (LUT) an LUT spacing for linearizing a power amplifier (PA). It optimizes the LUT spacing for the PA without prior knowledge of system state information. A size-N LUT divides a whole unsaturated PA input amplitude range into N bins, each predistorted by an entry of the LUT. The LUT is indexed by an input amplitude of a modulated signal via an index mapper to implement an unconditionally non-uniform LUT spacing. A spacing adaptor online interactively adapts the LUT spacing. The adapted LUT spacing balances the inter-modulation distortion (IMD) power at the PA output corresponding to each bin, so that the total IMD power at the PA output is minimized. This dynamically-optimum technique is practical, robust, and with low complexity.

Abstract: A noise filter, used for a digital signal, configuring an [N?1]-stage filter by connecting the N-number of flip flops in series comprises a selection unit for outputting a filter output signal by selecting one of signals filtered by one to (N?1) stages based on a selection signals; and a wave form check unit for making the selection unit change a selection thereby by changing a value of the selection signal based on a pulse width on the filter output signal which is output from the selection unit.

Abstract: A multi-mode multi-parallelism data exchange method and the device thereof are proposed to apply to a check node operator or a bit node operator. The proposed method comprises the steps of: duplicating part or all of an original shift data as a duplicated shift data; combining the original shift data and the duplicated shift data to form a data block; and using a data block as the unit to shift this data block so as to conveniently retrieve shift data from the shifted data block. With a maximum z factor circuit and duplication of part of data, specifications of different shift sizes can be supported. The functions of shifters of several sizes can therefore be accomplished with the minimum complexity.

Abstract: At a base station apparatus, known pilot signals for use in channel estimation are transmitted, and in addition thereto MCS pilot signals that are used to perform adaptive modulations respectively corresponding to a plurality of modulation schemes are multiplexed and output. A mobile station apparatus dispreads the respective MCS signals out of the multiplex signal, compares these to known symbols patterns, and sends the MCS pilot signals that show a matching relationship to the base station apparatus as a mobile station reception result. Upon receiving the mobile station reception result from the mobile station apparatus, the base station apparatus selects the modulation scheme of the optimum modulation level for the downlink signals. This configuration makes it possible to switch the modulation schemes in an accurate and simple way.

Abstract: The method is based on the capability for coordination of the radio activities of two mobile radio transmitting and/or receiving devices (3, 4). In the case of the method, a value of at least one characteristic variable (PRSSI,BT, N; 15, 16, 17) is first of all determined, which is characteristic of the requirement for coordination of the radio activity of one or both transmitting and/or receiving devices. The coordination of the radio activity of one or both transmitting and/or receiving devices is then activated or deactivated as a function of the value.

Abstract: A wireless communication system includes: an access point used the first channel or second channel to transmit the data, wherein the center frequency of the first channel is an initial frequency and the center frequency of the second channel is an target frequency; and a client terminal. When the client terminal receives the data from the first channel, the access point and the client terminal are operated by a first working frequency and second working frequency respectively. Initially, both working frequencies are located at the initial frequency. When the first channel is desired to switch to the second channel, the first working frequency is added an offset frequency. The second working frequency is adjusted and followed so as to keep up with first working frequency. By adding the offset frequency to the working frequency repeatedly, the first and second working frequencies are shifted until both of them arrive at the target frequency.

Abstract: In accordance with the present invention, a method and apparatus for estimating the noise and interference over the transmission band for OFDM systems are provided. Noise variance and signal-to-noise ratio (SNR) are important parameters for adaptive orthogonal frequency division multiplexing (OFDM) systems since they serve as a standard measure of signal quality. Conventional algorithms assume that the noise statistics remain constant over the OFDM frequency band, and thereby average the instantaneous noise samples to get a single estimate. In reality, noise is often made up of white Gaussian noise along with correlated colored noise that affects the OFDM spectrum unevenly. Provided is an adaptive windowing technique to estimate the noise power that takes into account the variation of the noise statistics across the OFDM sub-carrier index as well as across OFDM symbols. The proposed method provides many local estimates, allowing tracking of the variation of the noise statistics in frequency and time.

Abstract: The invention provides a method of selecting a modem carrier type for data transmission over a wireless communication system. An incoming call is received from a mobile vehicle and then an initial carrier tone is sent to a mobile vehicle in response to the incoming call. A modem response signal is received from a vehicle modem in response to the initial carrier tone. The modem response signal is determined to be either an analog modem response signal or a digital modem response signal, and then the call is connected to either the analog modem or digital modem based on the modem response signal determination.

Abstract: A communication system that transfers digital data on a fixed frequency channel of a radio frequency band in the presence of interference from at least one FHSS interference source includes a time diversity generation circuit. The time diversity circuit compacts a duration of data frames then replicate the time compressed data frames. The duplicated time compressed frames of data are transmitted to a communication receiver that has a time diversity data recovery circuit. The time diversity data recovery circuit buffers the received compressed and replicated data frames, evaluates whether each of the duplicated time compressed data frames are received correctly. If any one of the duplicated time compressed data frames is destroyed, the copy of the destroyed duplicated time compressed data frame is used to recover the data frame.

Abstract: Generating a notch in an Orthogonal Frequency Division Multiplexing (OFDM) frequency spectrum includes determining a first active interference cancellation (AIC) tone, comparing the first AIC tone with an amplitude limit, in the event that the first AIC tone exceeds the amplitude limit, constraining the first AIC tone, and determining a second AIC tone based at least in part on the first AIC tone. An Active Interference Cancellation (AIC) tone generator includes an interface configured to receive a plurality of tones, a processing component coupled to the interface, configured to determine a first AIC tone, compare the first AIC tone with an amplitude limit, and in the event that the first AIC tone exceeds the amplitude limit, constrain the first AIC tone, and determine a second AIC tone based at least in part on the first AIC tone.

Abstract: A predistorter includes: a divider that divides an input signal and supplies the divided input signal to a linear transmission path and a distortion generating path; a (2k?1)th-order distortion generator that raises the signal supplied to the distortion generating path to the (2k?1)th power to generate a distortion component; a vector adjuster that adjusts the amplitude and phase of the output of the (2k?1)th-order distortion generator; and an adder that sums up the output of the vector adjuster and the output of the linear transmission path to generate a predistorted signal r(t), in which the (2k?1)th-order distortion generator comprises: a (2k?1)th-order multiplier (27B4) that raises the divided signal to the (2k?1)th power; a lower-than-(2k?1)th-order multiplier (27B3, 27B2, 27B1) that raises the divided signal to the 5th, 3rd and 1st power, respectively; a vector adjuster (27C3, 27C2, 27C1) that adjusts the amplitude and phase of the output of the lower-than-(2k?1)th-order multiplier; and an adder (27D) t

Abstract: Methods and systems for processing a single sub-channel that includes two or more combined channels. Using intermediate frequency sub-sampling, two or more channels from a broad band signal are combined into a single sub-channel for further analog and digital processing. Each of the two or more channels is down converted to an intermediate frequency, filtered to remove certain undesired channels, and combined such that the two or more channels are adjacent to each other. A digital representation of the sub-channel is produced from the combined intermediate frequency channels. Each channel within the digital representation is down converted to baseband, and the in-phase and quadrature components are separated from each other. Compared to one direct down conversion technique, intermediate frequency sub-sampling as described in the application may reduce the number of analog to digital converters and control amplifiers used in analog processing by a factor of four.

Abstract: A method and device are provided for suppressing periodic interference signals, including a unit which is used to provide a period length for the periodic interference signal, an interference detection unit for detecting a signal corresponding to the interference signal, and a subtraction unit for subtracting the signal corresponding to the interference signal. The interference detection unit carries out multiple superpositioning of the input signal and scales the multiple superpositioned input signal depending on the period length of the interference signal in order to detect the signal corresponding to the interference signal.

Abstract: A method of and system for detecting an interfering multi-path condition is provided. A parameter is determined from a pulse of a correlation function derived from a received signal. The parameter is examined to determine if it is inconsistent with a non-interfering multi-path hypothesis. If so, an interfering multi-path condition is detected.

Abstract: A waveform acquisition system that captures and digitizes a wideband electrical signal through a bank of front end filters, frequency down converters, and conventional digitizers (A/D converters). A software algorithm reconstructs the composite input signal and applies the necessary corrections to remove the effects of hardware impairments. This approach is possible because it uses a class of filters that exhibit the quality of perfect waveform reconstruction, allowing signals whose spectral components overlap multiple filter bands, to be faithfully reconstructed. A calibration generator switched into the input port serves as a reference for quantifying and removing hardware errors. The channelized analog-to-digital converter (ADC) effectively multiplies the bandwidth and sampling rate of the conventional digitizer performance in a single channel by the number of channels in the system.

Abstract: Bit-Edge Zero Forcing Equalizer. A novel solution is presented by which a BE-ZFE (Bit-Edge Zero Forcing Equalizer) is employed to drive an error term within a data signal to an essentially zero value. This new BE-ZFE looks at values of data that occur at the bit edges of a data signal and drives the associated error term to zero. The new BE-ZFE is appropriately implemented within communication systems that are phase (or jitter) noise limited. Some examples of such communication systems include high-speed serial links one type of which serviced using a SERDES (Serializer/De-serializer) where data that is originally in a parallel format is serialized into a serial data stream and then subsequently de-serialized back into a parallel data stream.

Abstract: A digital amplifier and method are provided to convert digital base-band signals to a pair of digital switching waveforms switching at a carrier frequency to create a modulated RF signal. The digital amplifier contains variable frequency suppressed carrier PWM generators that produce in-phase and quadrature-phase differential signals, a mixer that combines the differential signals, a decoder that decodes the combined signals, and a power stage that receives signals from the decoder and provides an amplified signal at the carrier frequency using switches. The mixer combines the differential signals such that only one of the differential signals is output in a period. The carrier generators have integral noise shaping and use a random period signal to re-distribute quantization noise to a band outside an RF band of interest and reduce EMI of the RF signal.

Abstract: A method and apparatus for jointly estimating channels used to propagate desired and interfering signals received by a wireless receiver. A blind parameter estimator in the wireless receiver includes a forward parameter estimator and a backward parameter estimator that each include an equalizer and a channel estimator for generating forward and backward channel estimates, respectively, for the desired and interfering signal channels. In one embodiment, the blind parameter estimator includes independent forward and backward parameter estimators that generate independent forward and backward channel estimates, respectively, where a final channel selector selects the final channel estimates based on a comparison between error metrics associated with the forward and backward channel estimates.

Abstract: A codec circuit having a programmable digital bandpass filter is disclosed. According to one aspect, a bandpass filter matches the filter characteristics of the codec circuit to a transmitted pulse code modulation (PCM) signal. The codec circuit includes at least one programmable digital high-pass filter connected in series to at least one programmable digital low-pass filter. The setting filter characteristics for the programmable digital high-pass and low pass filters are each set by means of a signal identification device for identifying a PCM signal transmitted through the codec circuit. The filters are set as a function of the transmitted PCM signal in order to vary a bandpass filter characteristic for the programmable digital bandpass filter.

Abstract: The present invention relates to a method for transmitting data by means of at least one pulse sequence carried by a radio signal, in the course of which a power value representative of an amount of power carried by said pulse sequence is computed. The method according to the invention provides estimated values of noise affecting the radio transmission and of an amount of power which would be carried by each pulse sequence in the absence of noise, respectively, prior to the determination of a threshold value to which the power value is to be compared. The knowledge of such estimated values enables to compute a threshold value adapted to the communication conditions affecting any given pulse sequence, and hence to perform an optimal demodulation of any power-modulated UWB signal.

Abstract: A system, method and computer program product for stabilizing a coefficient set used by a digital predistortion (DPD) engine to apply pre-distortion to a transmit signal and cancel distortion generated by a distorting element or distorting system when transmitting the transmit signal, including obtaining an initial coefficient set; rotating the initial coefficient set to maintain a phase of fundamental components (w10(t), . . . , w1Q(t)) of the initial coefficient set a constant value; averaging the rotated coefficient set to obtain an averaged coefficient set; and applying the averaged coefficient set to the DPD engine.

Abstract: Described herein is a method of enhancing signals received by a receiver in a mobile telecommunications network. The method comprises correlating the received signals to produce a correlation and making a selection from the correlation to create a replica for enhancing the received signals.

Abstract: A linearizer and method. In a most general embodiment, the inventive linearizer includes a characterizer coupled to an input to and an output from said circuit for generating a set of coefficients and a predistortion engine responsive to said coefficients for predistorting a signal input to said circuit such that said circuit generates a linearized output in response thereto. In a specific application, the circuit is a power amplifier into which a series of pulses are sent during an linearizer initialization mode of operation. In a specific implementation, the characterizer analyzes finite impulse responses of the amplifier in response to the initialization pulses and calculates the coefficients for the feedback compensation filter in response thereto. In the preferred embodiment, the impulse responses are averaged with respect to a threshold to provide combined responses. In the illustrative embodiment, the combined responses are Fast Fourier Transformed, reciprocated and then inverse transformed.

Abstract: In an exemplary embodiment, an orthogonal frequency division multiplexing (OFDM) system includes an OFDM transmitter and an OFDM receiver that is configured to receive OFDM signals from the OFDM transmitter over a communication channel. The OFDM signals comprise a plurality of tones including data bearing tones that carry data and reserved tones for generating peak-to-average-power (PAPR) reduction signals. The OFDM system also includes a channel estimation component that is configured to estimate communication channel information for the data bearing tones and also for the reserved tones. The OFDM system also includes a tone selection component that is configured to determine tone selection information based on the estimated communication channel information.

Abstract: Systems and methods for monitoring impulse noise are described. At least one embodiment is a method, which comprises detecting whether impulse noise is present and in response to detecting the presence of impulse noise, performing time domain analysis to determine whether one or more impulse noise sources are present based on minimum interarrival time and maximum impulse length. The method further includes performing frequency domain analysis to estimate frequencies associated with the one or more impulse noise sources and based on the time domain analysis and frequency domain analysis, providing a total number of impulse noise sources and frequencies associated with the impulse noise sources. In this regard, the embodiments described herein provide dual-speed monitoring of impulse noise in the form of short-term and long-term monitoring.

Abstract: A wireless communication system includes an access point and first and second stations. The first station transmits a first message that includes an address of a second station as a destination address and an address of the first station as a source address. The access point forwards the message including the address of the second station address as the destination address and the address of the first station as the source address. The second station receives the message from the first station during a first time interval and receives the first message from the access point during a second time interval. The second station processes the duplicate received message to produce inbound data.

Abstract: Methods, systems, computer readable media and means for reducing errors in data caused by noise are provided. In some embodiments of the present invention, timing data is transferred from first circuitry to second circuitry. From the timing data, one or both of the first circuitry and the second circuitry detect whether noise is present as a result of the operations of the first circuitry. If it is detected that noise is present the second circuitry waits for the cessation of the noise before functioning again. If it is detected that no noise is present, the second circuitry functions.

Abstract: The present invention relates to digital-to-analog conversion. In particular, it has application to conversion of pulse code modulated signals, such as used in CDs and DVDs, to a pulse width modulated or analog signal.

Abstract: Methods and apparatus nullify an intrinsic jitter component in a digital clock recovery circuit induced by a time base frequency difference between an incoming data signal and a local synchronization clock for the digital clock recovery circuit. The techniques disclosed herein permit a recovered clock signal to be digitally filtered and applied to the digital clock recovery circuit clock synthesis unit (CSU) as a synchronization reference clock signal, which advantageously eliminates a time base frequency difference to reduce that jitter component and also reduces an intrinsic jitter component associated with jitter already present in the incoming data signal. In one embodiment, a state machine uses a filtered version of a recovered clock signal as a reference when the frequency of the filtered version of the recovered clock signal is relatively close to the frequency of the CSU reference clock signal.

Abstract: A receiver system that receives and recovers digital data on a fixed frequency channel of a radio frequency band in the presence of interference from at least one FHSS interference source. The digital data has a duration of data frames compacted then replicated to form duplicated time compressed data frames. The duplicated time compressed frames of data are transmitted to a communication receiver that has a time diversity data recovery circuit. The time diversity data recovery circuit buffers the received compressed and replicated data frames, evaluates whether each of the duplicated time compressed data frames are received correctly. If any one of the duplicated time compressed data frames is destroyed, the copy of the destroyed duplicated time compressed data frame is used to recover the data frame.

Abstract: An access terminal for processing a communication signal includes a receiver. The receiver is configured to determine a bias point for the communication signal based on a quality measurement of the communication signal, the quality measurement having a carrier-to-interference (C/I) estimate associated therewith. The receiver is further configured to determine a C/I cap for the communication signal using the C/I estimate, the C/I cap being configured to cap a signal to interference-plus-noise ratio (SINR) of the communication signal. In addition, the receiver is configured to process the communication signal using the determined bias point and the determined C/I cap. A method is also provided for processing a communication signal.

Abstract: A transmitter system that transfers digital data on a fixed frequency channel of a radio frequency band in the presence of interference from at least one FHSS interference source includes a time diversity generation circuit. The time diversity circuit compacts a duration of data frames then replicate the time compressed data frames. The duplicated time compressed frames of data are transmitted to a communication receiver that has a time diversity data recovery circuit.