Abstract: When a UE (12) is configured with MF-HSDPA and HARQ-ACK information associated with cells (14, 16) (characterized by potentially different downlink timing) is jointly encoded, only part of the existing Rel-9 HARQ-ACK codebook is reused. In one embodiment, only the codebook conflict arising from reuse of encodings is resolved. This is achieved by introducing a new codeword for at least one of the HARQ-ACK code words that are used multiple times in the existing Rel-9 codebook. In another embodiment, all codewords in the Rel-9 HARQ-ACK codebook having a Hamming distance smaller than a predetermined value (but not all codewords) are replaced. In yet another embodiment, all codewords in the Rel-9 HARQ-ACK codebook having a Hamming distance smaller than a predetermined value (but not all codewords) that would cause ambiguity at the NodeB receiver (i.e. where the interpretation of the HARQ-ACK information for one cell (14) depends on the number of streams transmitted at the other cell (16)) are replaced.

Abstract: Techniques are provided for detecting a coded signal in the presence of non-Gaussian interference. In an embodiment, a primary transmitter corresponds to a desired transmitter, and one or more secondary transmitters correspond to interfering transmitters. In an embodiment, received symbols, which include non-Gaussian interference and additive noise, are decoded to determine a set of message bits. In an embodiment, an estimate of the set of message bits may be determined using a minimum-distance detector or an optimal-ML detector, for example, depending on the signal-to-noise and/or signal-to-interference ratios at a receiver.

Abstract: The present technique relates to a transmission device, a transmission method, a reception device, a reception method, a program, and a communication system which can realize a system capable of promptly addressing a newly-generated disturbance wave. A broadcasting device of the present disclosure includes: a reception unit which receives reception interference information notified from the reception device; a setting unit which sets a frequency of a notch to be provided in a transmission signal on the basis of the reception interference information that has been received; a modulation unit which provides the notch in accordance with the set frequency of the notch while at the same time generates a modulated signal by modulating information to be transmitted; and a send-out unit which sends out the modulated signal as the transmission signal.

Abstract: Communication devices coupled via a communication link may comprise physical layer devices that may be operable to determine presence of a received signal and to mitigate noise in the signal prior to processing and/or validating the signal. Analog and/or digital signal processing may be utilized to process the signal and/or mitigate noise in the signal. Noise mitigation may comprise near-end crosstalk cancelling and/or echo cancelling and/or may utilize local transmit signal information. Subsequent to noise mitigation, samples of the noise reduced signal may be accumulated and/or an average signal strength and/or average signal power level may be determined. The average signal strength and/or average signal power level may be compared to one or more thresholds which may be configurable and/or programmable.

Abstract: Indication of an amount of processing performed in detection and removal of ingress noise may be provided. A frequency domain representation of a narrowband region of a digital input signal may be received. The received frequency domain representation of the narrowband region may be compared with a predetermined threshold. Results from the comparison of the received frequency domain representation of the narrowband region with the predetermined threshold may be aggregated. Based on the aggregated results, an indication of an amount of processing performed by an ingress exciser in removing the ingress noise may be provided.

Abstract: A communication apparatus and method in a wireless communication system that support multiple Orthogonal Frequency Division Multiplexing (OFDM) parameter sets. A method includes determining a respective OFDM parameter set for each of multiple Radio Frequency (RF) chains; and processing an OFDM signal in each of the multiple RF chains based on a parameter value defined in the respective OFDM parameter set.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus receives an intended signal from a first wireless device operating in a full-duplex mode, receives an interfering signal from a second wireless device communicating with the first wireless device, and reduces an interference of the received intended signal caused by the interfering signal by projecting a matrix of the received intended signal onto a space associated with the interfering signal.

Abstract: A communications system includes a receiver unit connected with a transmission channel. The receiver unit determines a signal power of a first communications signal received over the transmission channel. A transmitter unit is connected with the transmission channel and transmits a second communications signal, wherein a gain of the communications signal being output by the transmitter unit is controllable. A control unit controls the gain of the transmitter unit in response to the determined signal power. At the receiver unit, detection of broadcast signal ingress during data communication is improved and methods for avoiding disturbances between coexisting communications systems may become more reliable. Different distances between successive training symbols suitable for channel estimation may be provided to enhance the noise measurement.

Abstract: A receiver includes a first receiver chain configured to receive a first input signal and a second receiver chain configured to receive a second input signal. A first phase predistorter is provided in the first receiver chain and is configured to shift a phase of the first input signal by a first phase shift ??A(f). A combiner is coupled to the first receiver chain and the second receiver chain and combines the first and second input signals. The first phase shift is selected to cause undesired signal components received in the first and second input signals to combine destructively.

Abstract: One embodiment of the present subject matter includes a method of receiving an input signal. The method, in various embodiments, includes detecting a peak of the input signal and detecting an envelope of the input signal. In various embodiments, the peak and envelope are used to identify out-of-band blocking signals and to adjust gain control. The method also includes comparing the peak to a first threshold Tp and comparing the envelope to a second threshold Te. In the method, if the peak is above the first threshold and the envelope is below the second threshold, then ignoring the input signal. If the envelope is above the second threshold, the method includes applying automatic gain control to decode information encoded in the input signal.

Abstract: In mobile wireless communication systems the channel between the transmitter and receiver varies during a transmission. This is often referred to as fading, of which different kinds exist—each resulting in different impairments with specific properties. A low complexity scheme is described to reduce the noise created by inter-carrier interference or ICI. The method makes use of the guard interval and assumes slow variation of the channel. It is not restricted to wireless communication and can be used in any environment with varying channels.

Abstract: Systems and methods for computing a decoder noise power estimate are provided. A pilot signal transmitted through a fading channel from a wireless transmission source is received. Signal power of the received pilot signal, channel noise power, and channel estimation error are computed. The decoder noise power estimate is determined based on the computed signal power, channel noise power, and channel estimation error.

Abstract: A receiving station receives an orthogonal frequency division multiplexing (OFDM) symbol via a shared medium, the OFDM symbol comprising a first set of frequency components modulated with preamble information and a second set of frequency components modulated with information. The receiving station processes sampled values of the received OFDM symbol based on channel characteristics estimated from the first set of frequency components to decode information encoded on a first subset of the second set of frequency components. The receiving station processes sampled values from the first symbol based on channel characteristics estimated from the first set of frequency components and the first subset of the second set of frequency components to decode information encoded on a second subset of the second set of frequency components.

Abstract: A wireless communication device for a CDMA system is configured to generate power estimates with reduced estimation bias. The power estimates may be used for delay estimation, MMSE channel estimation, demodulation, or other purposes. The wireless communication device produces first set of power estimates for a first set of delays and generates a model of the signal powers at the first set of delays as a function of the power leakage from non-aligned signal images in the received signal into the first set of delays.

Abstract: An accurate channel frequency response is obtained by processing an extracted number of pilot tones provided at different locations within a received OFDM symbol. This includes filtering the extracted pilot tones with a first window function, converting the thus filtered pilot tones to a first channel impulse response signal that may include a main tap and a plurality of adjacent taps, removing taps whose absolute values or energy levels are below a predetermined level, processing the remaining taps having sufficient absolute values or energy levels into a second channel impulse response signal that is significantly free of noises, converting the second channel impulse response signal to a frequency-domain signal, and filtering the frequency-domain signal with a second window function having an inverse characteristic of that of the first window function to obtain an accurate channel frequency response.

Abstract: Generating updated coefficients for an adaptive equalizer involves generating phase tracking information using asynchronous detection strategy (ADS) based on resolved data, and equalized signals, and estimating a phase corrected error based on the equalized signals, the phase tracking information and the resolved data. An inhibit signal is generated to inhibit updating of the equalization coefficients, the inhibit signal representing a likelihood of the phase corrected error being accurate, determined according to the phase corrected error, and the equalized signals. The equalization coefficients for the equalizer are adapted based on the received signals, and on the phase corrected error, and the adapting is inhibited according to the inhibit signal. Compared to conventional ADS, the new combination with the inhibit signal can enable improved convergence of coefficient adaptation. This is particularly useful for coherent receivers for optical systems.

Abstract: Provided are a soft demapping apparatus and method that may cancel interference included in a rotated quadrature amplitude modulation (QAM) signal, using at least one interference cancellation unit, and may perform one-dimensional (1D) soft demapping of the interference-cancelled rotated QAM signal.

Abstract: Apparatus and methods mitigate a problem of equalizing communications signals that have been distorted by severe non-linearities such as clipping or harsh compression. For example, severe non-linearity occurs when signal compression or signal clipping occurs at rates above 20% of the data transmission interval. Severe non-linearities may significantly reduce system performance. Disclosed techniques selectively apply DSP equalization based on the detection of non-linearity for a present sample or one or more samples prior to the present sample. These techniques can be implemented in relatively low-cost high-speed SerDes designs to improve eye openings and reduce sensitivity to InterSymbol Interference (ISI) and to improve bit error rate (BER).

Abstract: Systems and methods for suppressing transmitter noise in a receive band of a co-located receiver that are suitable for wideband applications are disclosed. In one embodiment, an analog radio frequency transmit signal output by a transmitter includes a desired signal in a transmit band of the transmitter and transmitter noise in a receive band of a main receiver. A secondary receiver obtains a secondary receiver input signal that is representative of at least the transmitter noise in the receive band of the main receiver and outputs a digital feedforward signal. A digital feedforward transmit noise cancellation subsystem generates a digital transmitter noise cancellation signal that is representative of the transmitter noise in the receive band based on the digital feedforward signal and subtracts the digital transmitter noise cancellation signal from a digital receive signal output by the main receiver to thereby provide a compensated digital receive signal.

Abstract: A method of transmitting communication signals to a plurality of targeted receivers includes transmitting one or more information streams for individual ones of the targeted receivers according to ongoing transmission scheduling, and controlling the ongoing transmission scheduling to reduce the number of impairment contributors that must be considered in received signal processing by scheduled ones of the targeted receivers. In one embodiment the controlling comprises scheduling the targeted receivers to avoid transmissions to more than one targeted receiver at a time. In the same or another embodiment, the controlling comprises at least one of using equal transmit power allocations for one or more information streams, and using fixed transmit power allocations for one or more of the information streams.

Abstract: Access terminals are adapted to facilitate estimation of signal-to-noise ratios for received wireless transmissions. According to at least one example, a wireless communication device can receive a plurality of data symbols. The wireless communication device can determine a first estimate of a signal-to-noise ratio based on first estimates of a signal power and a noise power associated with the plurality of received data symbols. When the first estimate of the signal-to-noise ratio is below a predetermined threshold, a second estimate of the signal-to-noise ratio can be determined based on second estimates of the signal power and the noise power for the received data symbols. Other aspects, embodiments, and features are also included.

Abstract: Various devices and methods are provided that use signaling to support advanced wireless receivers. For example, a method includes receiving an input signal at a user equipment. The input signal includes a desired signal and an interfering signal, where the desired signal defines symbols using constellations. The method also includes obtaining information identifying a wireless channel used by the interfering signal and a modulation type used to modulate data in the interfering signal. The method further includes recovering the symbols from the desired signal using the information.

Abstract: The present invention provides a carrier wave reproduction device in which bit-error characteristics are improved without decreasing transmission capacity.

Abstract: Wireless receiver circuits and methods include algorithms for switching between a least-squares/minimum mean-square error method of channel estimation known as the CE algorithm, and a continuous plot method of channel estimation known as the CPCE algorithm based upon channel characteristics to improve reception of wireless communications in different reception conditions. In an embodiment, the CPCE algorithm may be selected by a processor for use in channel estimation when a calculated number of candidate paths is less than or equal to a first threshold value, a calculated power ratio of the L strongest paths to the total of all paths is greater than or equal to a second threshold value, and the maximum Automatic Gain Control variation is greater than or equal to a third threshold value. Threshold values may be based on field testing, and set to values at which the CE or CPCE algorithm exhibits better performance.

Abstract: An outdoor radio communication system comprises a first radio unit, a second radio unit, and a single cable coupling the first radio unit to the second radio unit. Each radio unit includes a downconverter, a radio processor that is communicatively coupled to the downconverter, and a XPIC module. The cable further includes a first twisted-pair of wires for communicatively coupling the first downconverter to the second XPIC module and a second twisted-pair of wires for communicatively coupling the second downconverter to the first XPIC module. The first XPIC module generates a first reference signal using a signal from the second downconverter to cancel cross-polarization interference in an output signal of the first radio processor. Similarly, the second XPIC module generates a second reference signal using a signal from the first downconverter to cancel cross-polarization interference in an output signal of the second radio processor.

Abstract: Methods and systems to configure a receiver based on a channel condition. A system may be implemented to estimate a channel based on PN sequences in a received signal, concurrently equalize a frequency domain representation of the signal with multiple blind adaptive equalizers, and evaluate results of the equalizations to select coefficients of one of the equalizers for further processing. A first equalizer may implement a constant-step-size (CSS) algorithm for a static channel. A second equalizer may implement a variable-step-size (VSS) algorithm for a dynamic channel. Static and dynamic channels may be distinguished based on convergence/divergence of the equalizers, which may be determined from a mean square error estimated from PN sequences in results of the blind equalizations.

Abstract: A receiver is provided that receives signals from a device under test (DUT) for one or more modes of operation. For each mode, the system detects beacon transmission signals from the DUT, and counts the number of beacons for a period of time. If the count is not consistent with an expected count, e.g. a stored value, the system may preferably provide an output to indicate that there is a problem with the DUT. If the count is consistent with the expected count, the system may preferably perform further testing for other modes of operation. If the count output of the DUT is consistent with expected counts over each of the operation modes, the system may provide an indication that the DUT has passed the beacon tests.

Abstract: Methods and apparatus for efficiently feeding back preceding information in a multiple input multiple output (MIMO) system. A codebook including a plurality of codebook entries is constructed. A plurality of subsets of codebook entries are defined for the codebook. Each subset includes a plurality of codebook entries. A subset of codebook entries is selected for precoding data in dependence upon a channel condition, and a codebook entry is selected from the subset. Then, a subset index corresponding to the selected subset, and a codebook entry index corresponding to the selected codebook entry within the selected subset, is transmitted as feedback information.

Abstract: The present invention discloses a method and a device of sending and receiving precoding information. A terminal terminal obtains a wideband precoding matrix indicator PMI. The terminal encodes an MSB of the wideband PMI to obtain encoded information. The MSB of the wideband PMI is encoded separately or jointly with other information and the MSB is a part of the wideband PMI. The terminal sends encoded information to a data sending end.

Abstract: Embodiments of the present invention provide a receiver and a receiving method. The receiver comprises: a branch forming unit a plurality of signal branches; each of the signal branches comprising a joint processing unit; and the joint processing unit being used to eliminate an inter-carrier interference of the subcarrier signal in a present signal branch and the subcarrier signals in other signal branches adjacent to the present signal branch. With the embodiments of the present invention, the inter-carrier interference may be eliminated and the performance of the system may be improved; and the sampling rate of the analog digital converter may also be lowered.

Abstract: A method includes a first step of receiving a signal at a first receiver circuit on the basis of a mobile communications standard supporting multiple predefined modulation alphabets wherein the received signal includes first data dedicated to the first receiver circuit and second data dedicated to a second, different receiver circuit, a second step of determining a modulation alphabet of the multiple predefined modulation alphabets during an operation of the first receiver circuit and a third step of detecting data depending on the second data at the first receiver circuit on the basis of the determined modulation alphabet.

Abstract: Methods and apparatus for the intelligent association of control symbols with special symbols that are transmitted over a network. In one embodiment, the association is utilized to improve DC-balance on a transmission medium. In an exemplary variant, the special symbols originate from line codes such as the 8B/10B line code, which format a digital signal so that is optimized for transmission over a given physical channel. These control symbols are divided up according to a first criterion, while the special symbols are further divided up according to a second criterion. The divided control symbols are then allocated to the divided special symbols using a pre-designated allocation algorithm, which may or may not include a scrambling algorithm. The allocation of the control symbols improves signal characteristics and electromagnetic interference (EMI) when various ones of control symbols are ultimately transmitted over a given transmission medium.

Abstract: Apparatus and methods are disclosed to improve a user equipment's capability of performing time and frequency tracking by utilizing two carriers when the channel interference on one of the carriers is greater than a certain threshold. In one aspect of the disclosure, a user equipment (UE) determines that channel interference of a first carrier is greater than an interference threshold. The UE performs frequency tracking and time tracking in accordance with information received from a second carrier, and performs interference cancellation in accordance with the frequency tracking and time tracking. Other aspects, embodiments, and features are also claimed and described.

Abstract: This disclosure provides a clock recovery circuit for a multi-lane communication system. Local clocks are recovered from the input signals using respective local CDR circuits, and associated CDR error signals are aggregated or otherwise combined. A global recovered clock for shared use by the local CDR circuits is generated at a controllable oscillation frequency as a function of a combination of the error signals from the plurality of receivers. A voltage- or current-controlled delay line can also be used to phase adjust the global recovered clock to mitigate band-limited, lane-correlated, high frequency jitter.

Abstract: A current channel estimate H0(k) based on previously received pilot tones is provided. To update that current channel estimate, an iterative process is performed for each instance of receiving a set of Np new pilot tones within an nth time sample index. For each iteration: generate an updated channel estimate Hupd(k) by replacing contributions to the current channel estimate H0(k) that depend from the previously received pilot tones with contributions that depend from the set of Np new pilot tones; and consider for the next iteration the updated channel estimate Hupd(k) as the current channel estimate H0(k) and the set of Np new pilot tones as the previously received pilot tones A windowing function w(n) defines a frequency span within which are disposed each of the received sets of Np new pilot tones. Improvements are quantitatively shown at FIGS. 2 and 4A-B.

Abstract: A method and apparatus for mitigating a phase anomaly in an analogue-to-digital converter (ADC) output signal is disclosed. A plurality of codewords output by the ADC are received and information about an estimated level of interference between an output of the ADC and an input of the ADC due to the codeword is obtained for each codeword based on the logic values of bits in the codeword. In-phase (I) and quadrature (Q) corrections are obtained based on the information about the estimated level of interference, and applied to I and Q values obtained from the ADC output signal.

Abstract: In one aspect, a method for mitigating an effect of an interfering radio signal at a multiple antenna receiver includes forming an estimate of a relationship of the interfering signal among signals received from the multiple antennas. In general, the interfering signal does not share the same communication technology as a desired signal. The signals received from the multiple antennas filtered and combined according to the estimate of the relationship of the interfering channels to reduce an effect of the interfering signal. Desired data present in the desired signal represented in the filtered and combined signals is decoded and the estimate of the relationship of the interfering signals is updated according to the decoding of the desired signal.

Abstract: Systems and methods for establishing transmission format parameters between communication devices are provided. In some aspects, a method includes identifying, by a first base station, a first communication session with a first user equipment. A master set of transmission format parameters is shared between the first base station and the first user equipment. The method also includes assigning a first subset of the master set of transmission format parameters to the first communication session. The first subset is specifically assigned to the first communication session and specifies which of the master set of transmission format parameters is allocated for use in the first communication session. The method also includes transmitting an indicator of the first subset to the first user equipment.

Abstract: An adaptive tuning method comprises the steps of: obtaining a statistical result; determining whether an adaptive tuning procedure is to be performed in accordance with the statistical result; obtaining reference information of the first wireless module; and performing the adaptive tuning procedure in accordance with the reference information.

Abstract: In a process variable transmitter, a sensor signal is sampled, using a clock signal, at a sensor sampling frequency. Interference is also sampled at the sensor sampling frequency. A comparison is made to determine whether the interference at the sensor sampling frequency or harmonics of the sensor sampling frequency exceed a threshold level. If so, the clock signal is changed to adjust the sensor sampling frequency away from the frequency of the interference.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus receives a first message from a first wireless communication device and a second message from a second wireless communication device, obtains information associated with a first processing delay with respect to the first message and a second processing delay with respect to the second message, and transmits a third message comprising an indication of the information associated with the first and second processing delays.

Abstract: A system and method for providing multi-beam Wi-Fi access points. The system includes one or more Wi-Fi transmit antennas beamformers; one or more Wi-Fi receive antennas or receive beamformers; and a number N of co-channel Wi-Fi access points (APs) and a number of M non co-channel APS, where all APs comply with IEEE802.11xx standard, connected to the Wi-Fi transmit antennas beamformers, wherein the Wi-Fi transmit antennas beamformers are configured to produce a plurality of non spatially adjacent beams of a common frequency, directed at a plurality of Wi-Fi user equipment (UE) such that the directional beams are sufficiently isolated from each other, and at least some of the Wi-Fi UEs communicate simultaneously with the plurality of Wi-Fi access points.

Abstract: A method for detecting multi-user signals including conducting a first energy burst detection detecting a first plurality of user signals as a first energy burst, attempting to decode a user signal from the first plurality of signals within the first energy burst, cancelling out a first user signal from the first energy burst if the first user signal is successfully decoded from the first energy burst, determining a second user signal to be discarded if the second user signal is not successfully decoded from the first energy burst, conducting a second energy burst detection detecting a second plurality of signals as a second burst, and iteratively cancelling out the first user signal successfully decoded from the first energy burst from the second energy burst, wherein the second energy burst detection is conducted when all user signals within the first energy burst are either cancelled out or determined to be discarded.

Abstract: To compensate for second-order intermodulation (IM2), it is determined whether a blocking signal is present at a receiver. A biasing differential is applied across downconverting mixers in the receiver that minimizes cross-correlation of quadrature signal components of a signal produced by the receiver in the presence of the blocking signal.

Abstract: A technique for calibrating a receiver apparatus comprising at least one analog signal processing component and an intermediate frequency, or IF, mixer for converting IF signals comprising an in-phase, or I, signal and a quadrature-phase, or Q, signal to baseband frequency signals is provided. The IF mixer is arranged downstream of the at least one analog signal processing component. A method implementation of the technique comprises the steps of determining, in a digital processing domain downstream of the IF mixer, a metric which is affected by a frequency dependency of an imbalance between I and the Q signal, or IQ-imbalance, over a signal bandwidth, generating, based on the metric thus determined, a calibration signal configured to at least partially compensate a frequency-dependency of the IQ imbalance, and feeding the calibration signal to the at least one analog signal processing component so as to calibrate the at least one analog signal processing component.

Abstract: A system for correcting gain imbalance and phase imbalance between first (IOUT) and second (QOUT) signals which are 90° out of phase, including circuitry for estimating the phase mismatch (?) and gain mismatch (?) between the first signal and the second signal signals in a plurality of frequency bands. An inverse fast Fourier transform is performed on each of a number of arrays of the phase mismatch estimates and the gain mismatch estimates to generate correction filter coefficients (h[N]) for a N tap correction filter. The N tap correction filter filters an uncorrected value of the second signal to generate a corrected value of the second signal.

Abstract: A method of calculating combining weight vectors associated with a received composite information signal comprising at least one data stream transmitted from at least a first antenna and a second antenna is disclosed. The method starts with computing a parametric estimate of an impairment covariance matrix including at least a first impairment term associated with common pilots deployed by the first antenna and the second antenna respectively. The first impairment term captures effects of interferences between the common pilots, in addition to effects of interferences caused by each common pilot singly. The impairment covariance matrix further includes a data covariance term capturing effects of the at least one data stream and an interference term caused at least partially by contribution of thermal noise of receiver branches. Then the method computes the combining weight vector using the computed impairment covariance matrix.

Abstract: Systems and methods of interference-triggered frequency hopping in a wireless communication system. A master is provided in the wireless communication system in wireless communication with slave nodes each configured to use different preselected communication frequencies to permit frequency hopping. A current channel is selected from among multiple channels in the wireless communication system in which the master and at least some of the slave nodes send and receive wireless communications. Each of the channels uses different ones of the preselected communication frequencies. In the current channel, interference with communications between the master and a selected one of the slave nodes that use the current channel is detected. A new channel is selected only in response to detecting the interference. The system switches from the current channel to the new channel such that communications between the master and the selected slave node use the new channel.

Abstract: A receiver communicating according to a wireless communication protocol standard for filtering a signal received at a single antenna. The receiver includes filter modules, receiver modules, and a summer. The filter modules receive from antennas multipath components of the signal as transmitted to the receiver. The signal includes bits of data. Each of the filter modules: receives corresponding ones of the multipath components of the signal as received at a respective one of the antennas; and according to the wireless communication protocol standard, filters the signal as received at the respective one of the antennas to generate a filtered signal. The receiver modules respectively receive the filtered signals. Each of the receiver modules combines the multipath components in the respective filtered signal to generate an output signal. Each of the output signals includes a respective version of the bits of data. The summer sums the output signals.

Abstract: A radio receiver comprising: an antenna for receiving a radio frequency signal amplitude modulated with an audio frequency signal; a digitizer for periodically sampling the radio frequency signal and generating a digital reception signal representative of the amplitude of the radio frequency signal; and a demodulator for demodulating the digital reception signal to generate a representation of the audio frequency signal.