Abstract: A wavelet transform noise minimization circuit comprises a differential receiver, a voltage comparator, a wavelet transform circuit, an electrical idle (EI) detector circuit, a phase interpolator, a phase-locked-loop (PLL), and a reference clock buffer. The wavelet transform noise minimization circuit may be beneficially applied wherever there is non-deterministic (e.g., random) noise in the PHY layer during an electrical idle state. The wavelet transform noise minimization circuit may be used to improve noise margin during an electrical idle state, and/or reduce the occurrence of false activation of a PHY layer when in the electrical idle state.

Abstract: In one embodiment of the method of adaptively selecting an airlink coding scheme in a telecommunications network, a coding scheme operating region is determined based on a currently used coding scheme and measurements representative of a block error rate. A block error coding scheme is determined based on the determined coding scheme operating region. In another embodiment of the method of adaptively selecting an airlink coding scheme in a telecommunications network, a first coding scheme is determined based on measurements representative of one or more conditional channel quality metrics, and a second coding scheme is determined based on measurements representative of a block error rate. One of the first and second coding schemes is selected as the coding scheme.

Abstract: A method and device for estimating a Gaussian white noise power in a channel and a receiver are provided. The method includes performing a multi-path search on a received signal to find out paths of the signal; performing a noise estimation on one of the paths to acquire a total noise power of the path; performing an inter-path interference noise estimation on N paths spaced apart from the path by an integral number of chips to obtain an inter-path interference noise power of a single path of the signal, where N is an integer greater than or equal to 1; and subtracting the inter-path interference noise power from the total noise power to obtain the Gaussian white noise power. Through the technical solution of the disclosure, the Gaussian white noise power in a channel is obtained with a higher accuracy, so that the performance of equalization is enhanced.

Abstract: To test for in-house wiring problems, upstream transmission profiles are tuned automatically and remotely, and reactive downstream parameter modifications indicative for in-house wiring problems are measured.

Abstract: A method, circuit and system for altering the power consumption in communication links. A type of noise and an amount of jitter in a signal transmitted across a communication link is measured. Upon determining the contribution of the measured noise to the measured jitter in the signal, the measured noise is classified based on such contribution and the intensity of the measured jitter. The power consumption in a component(s) of the communication link may be adjusted based on the classification of the measured noise. For example, if the measured noise is classified as being a low amount of noise, then the power consumption of the component(s) may be reduced such as by lowering the voltage of the power supply and/or reducing the complexity of the circuitry. By reducing the power consumption when the communication link is not subject to the worst-case condition, a savings in power consumption may be made.

Abstract: The invention provides a method and system for selecting an operation profile, which belongs to the field of network communication. In order to solve the problem of the selected operation profile being unsuitable for the broad bandwidth and traffic in the prior art, the invention provides a method for selecting an operation profile, comprising: obtaining channel information of a channel; selecting the operation profile according to the channel information and a predetermined selection rule. The invention also provides a system for selecting an operation profile comprising a channel information obtaining module and a profile selecting module. With the technical solution of the invention, it may select a suitable operation profile self-adaptively according to the actual channel condition.

Abstract: A transceiver comprises a communication line interface, memory, and logic. The memory stores predefined noise spectra, and the logic is configured to analyze an initialization signal received from the communication line coupled to the communication line interface during an initialization phase that precedes a data phase. The logic is configured to automatically select one of the predefined noise spectra based on the initialization signal and to combine the selected noise spectrum with the initialization signal to calculate a value. The logic is configured to perform a comparison between the value and a threshold and to make a determination, based on the comparison, whether a data signal to be communicated in the data phase will be spectrally compatible, if the data signal is transmitted at a data rate of the initialization signal. The logic is further configured to select a data rate for the data signal based on the determination thereby ensuring that the data signal is spectrally compatible.

Abstract: Method and apparatus for retrieving the channel frequency response H(f), the noise N(f), measured at initialization and the signal to noise ratio SNR(f) measured at show time on a per bin basis, in the upstream or downstream direction. Initialization H(f) is used for analyzing the physical copper loop condition between tip and ring. Initialization N(f) is used for analyzing the crosstalk. Showtime SNR(f) is used for analyzing time dependent changes in crosstalk levels and line attenuation. The combination of H(f), N(f) and SNR(f) allows analysis of the line conditions for reaching the maximum data rate of a given loop, scheduling maintenance and plant update.

Abstract: A factor in deterioration of receiving characteristics of an antenna is automatically determined and automatically improved. In an apparatus for receiving digital broadcast signal, when receiving the signal, a received signal sent from the antenna 1 is orthogonally detected to a baseband signal; an average value of amplitude in radial direction of signal points of phase mapping of the baseband signal is then measured to calculate a C/N value for the received signal; an average value of amplitude in circumferential direction of signal points of the phase mapping of the baseband signal is measured to calculate an amount of phase noise of the received signal; a bit-error rate of transport stream that is given by demodulating the baseband signal is then measured; a factor in deterioration for receiving characteristics of the antenna is determined based on these results; and a desired measure mode is set based on the determination result thereof.

Abstract: A method, computer program product, and system are provided for computing link supportability in a WCDMA communications system. For example, the method can be used to calculate link supportability of a transponder in satellite communications system (e.g. MUOS) in a user-to-base direction. This method can include expressing a carrier signal to noise ratio spectral density for a communication link of interest in terms of a transponder input power of the communication link of interest, a spectral overlap factor representative of one or more interfering communication links, and a transponder input power of the one or more interfering communication links. Assumptions and approximations can be made to simplify the spectral density expression in order to reduce a dimensionality of terms used in the computation of the expression. As such, in reducing dimensionality, the expression becomes a manageable computation for WCDMA communication systems to evaluate.

Abstract: A system includes a receiver for receiving a modulated signal. The receiver includes a gain estimator for converting complex data representative of constellation points of the modulated signal into scalar data representation. The gain estimator is configured to fold a first portion of the scalar data representation onto a second portion of the scalar data representation. The gain estimator is further configured to estimate a constellation gain value from the folded first portion and the second portion of the scalar data representation.

Abstract: A transmitter (1) converts an input signal from a microphone (2) into a plural-bit digital signal by means of an A/D converter (4) at predetermined time intervals. An encoder (6) divides the digital signal into plural blocks and adds a parity bit to each block to thereby form a coded signal. A transmitting unit (8) modulates a carrier with the coded signal and transmits the modulated carrier through an antenna (10). A receiver (12) includes two tuning units (18A, 18B). Corresponding coded signals outputted from the tuning units (18A, 18B) are inputted to a decoder (20). The decoder (20) makes a parity check on respective blocks of the corresponding coded signals and selects and outputs an error-free one of the corresponding blocks of the corresponding coded signals.

Abstract: The present invention relates to a method and apparatus for estimating a channel in a mobile communication network. In particular, the present invention relates to a method of estimating a channel under a channel environment where interference between neighboring base stations exists in a mobile communication network using an orthogonal frequency division multiplexing (OFDM) method. In order to estimate a channel, one cluster is divided into two sub-clusters, and pilot sub-carrier signals included in at least one sub-cluster in an OFDM symbol direction are used. Therefore, it is possible to further improve performance as compared to a method of estimating a channel by using pilot sub-carriers included in one cluster.

Abstract: The present invention relates an apparatus and method of estimating a signal-to-noise ratio (SNR) of a received signal when the received signal has a timing offset. An apparatus for estimating a signal-to-noise ratio (SNR) according to an exemplary embodiment of the present invention includes a fast Fourier transform (FFT) unit that performs a fast Fourier transform on a received signal to convert the received signal into a frequency domain signal; a preamble selector that extracts a preamble from the frequency domain signal; a correlator that correlates the preamble to a preamble reference signal generated by a receiver to calculate a correlation value; an entire power estimator that calculates entire power; a noise power estimator that applies a differential demodulation method to the correlation value to remove a timing offset and calculate noise power; and an estimating unit that uses the entire power and the noise power to estimate the signal-to-noise ratio (SNR).

Abstract: Certain aspects of the method may comprise generating models for a received plurality of spatially multiplexed communication signals for multiple channels from a plurality of transmit antennas. A calculated signal to noise ratio (SNR) of each multiple channel may be maximized based on the generated models. A phase and an amplitude of at least a portion of the received plurality of spatially multiplexed communication signals may be adjusted based on a plurality of amplitude and phase correction weights determined from the maximized SNR.

Abstract: Provided are an apparatus and method for measuring a carrier-to-interference-and-noise ratio (CINR) using down-link preambles. More particularly, provided are an apparatus and method that measure CINRs according to a plurality of logical bands in a downlink band-adaptive modulation and coding (AMC) channel mode zone using preambles and determine whether or not to switch to another channel mode or logical band on the basis of the CINRS. According to the apparatus and method, it is possible to easily measure a plurality of CINRs and switch to a better channel mode or another logical band using the measured CINRs. Consequently, the optimum channel environment can be maintained.

Abstract: Rate selection with margin sharing in a system with independent data stream rates is presented. Signal-to-Noise Ratio (SNR) estimates are obtained for each stream. Rates are selected for the streams based on the SNR estimates, such that at least one data stream has an SNR margin below a threshold, each remaining data stream has an SNR margin above a respective threshold, and the total SNR margin for all streams is above a total threshold. For rate selection with margin sharing with a vector-quantized rate set, SNR estimates are obtained for usable transmission channels. The total SNR margin is determined for each rate combination based on the estimates. Each rate combination is associated with a specific number of data streams to transmit, a specific rate for each data stream, and a specific overall throughput. The combination with the highest overall throughput and non-negative total SNR margin is selected.

Abstract: A method for identifying noise sources for automation devices (1, 2) which have a multiplicity of input/output modules (2a, 2b, . . .

Abstract: A method of tracking on-time errors may include producing first and second metrics from accumulated signal samples of a received data frame, and calculating a sum of, and a difference between, the first and second metrics. The calculated difference and sum values may be used to determine an estimated on-time error for the received data frame and a corrected timing error control value to be applied to the on-time error. The accuracy of the estimated on-time error may be evaluated based a signal quality metric to determine whether the corrected timing error control value is to be applied to the estimated on-time error or whether the timing adjustment for the on-time error is to be stopped.

Abstract: Synchronization of satellite and terrestrial broadcasts in a shared frequency arrangement is use in order to facilitate simultaneous reception of the broadcasts. A delay value is adjusted based on a synchronization between a first terrestrial broadcast and a satellite broadcast, and a delay value for a second terrestrial broadcast is adjusted based on a synchronization between the second terrestrial broadcast, the first terrestrial broadcast and the satellite broadcast. The adjustment of the relative delay values provides an improved reception pattern based on receipt of a shared frequency communication from multiple sources by improving a signal quality factor within at least selected regions of the coverage areas in which the relative delay values permit synchronization.

Abstract: A multiple carrier wireless communications system includes a channel predictor, a performance predictor, and a link adapter. The channel predictor predicts channel state information for a next packet based on channel state information for the current packet. The performance predictor includes an uncoded performance predictor to predict system performance at a decoder input based on a modulation type and the predicted channel state information for the next packet, and a decoder input-output performance mapper to predict system performance at a decoder output based on a coding rate and the predicted system performance at the decoder input. The link adapter includes a link throughput controller to generate a throughput indicator based on a requested system performance and the predicted system performance at the decoder output, and a modulation and coding scheme (MCS) updater to identify a MCS based on the throughput indicator.

Abstract: The present invention implements a method and system for dynamically adapting the modulation and coding scheme for radio links in a wireless communications network based on a retransmission environment model in order to maximize throughput and most efficiently allocate bandwidth resources. The present invention encompasses a refined calculus and methodology for deriving the link adaptation thresholds in a retransmission environment using a complex model and analysis of the retransmission environment. The present invention holds particular application for wireless data communications as opposed to real time data services because it is based on a retransmission model applicable primarily for data services. A critical component of this new link adaptation system is a “no transmission” cutoff mode that is selected for SIR below a base threshold value. This new mode prevents system instability and misallocation of bandwidth in a wireless communication system.

Abstract: Frequency error combination for a multi-channel data detection system with a phase locked loop for each channel, comprises receiving frequency error information with respect to each channel; combination logic configured to combine the received frequency error information and generate a combined phase error, weighting the received frequency error information from each channel; and a frequency error output configured to apply the combined frequency error to at least one channel phase locked loop.

Abstract: Phase-error combination for a multi-channel data detection system with a phase locked loop for each channel, comprises receiving phase error information with respect to each channel; combination logic configured to combine the received phase error information and generate a combined phase error; and a phase-error output configured to apply the combined phase error to at least one channel phase locked loop. Additionally, error signal combination comprises receiving error information of a signal relevant to a phase locked loop with respect to each channel; combination logic configured to combine the received error signal information and generate a combined error signal, weighting the received error signal information from each channel, for example with reliability information. An error compensation output is configured to apply the combined, weighted error signal to at least one channel phase locked loop.

Abstract: Antenna noise temperature is determined for a handheld wireless communication device which typically includes a radio, e.g. having a wireless transceiver and associated circuitry connected thereto, and an antenna connected to the radio. The method includes measuring an antenna thermal noise component, measuring a radio noise component, measuring an environmental background noise component, and determining the antenna noise temperature based upon the measured antenna thermal noise, radio noise, and environmental background noise components. The method may include measuring antenna efficiency, and determining further includes weighting at least one of the measured antenna thermal noise, radio noise and environmental background noise components based upon the measured antenna efficiency.

Abstract: Noise detection is performed by using the output of the phase comparator that the PLL comprises. The phase comparator outputs a signal that is based on the phase difference between the output of the voltage controlled oscillator and the reference signal. The phase difference reflects the effect of noise on the PLL and, in addition to the characteristics of the noise itself, such as the wave height value of the noise and the frequency component thereof, reflects the tolerance of the PLL to noise, whereby the level of risk that the system can actually be caused to malfunction can be judged.

Abstract: An integrated tuner circuit has an arbitrary IF (intermediate frequency) output. The tuner includes an integrated circuit with a fixed-frequency control loop and a matched external variable capacitance Ct, to achieve tracking of a tuned LC band-pass filter with an arbitrary oscillator.

Abstract: A technique for determining a received signal strength indicator of a target base station at a subscriber station includes performing a discrete Fourier transform on a received signal to provide a transformed signal. In this case, the transformed signal occupies one or more segments of a channel and the one or more segments each include multiple subcarriers. A shift-n cross-correlation is calculated based on the transformed signal and a preamble sequence of the target base station to provide a coarse received signal strength indicator for the target base station.

Abstract: A method for estimating the signal quality of a communication channel is disclosed. Firstly, an input signal passes through a match filter at the initial stage of an estimation period. Next, the output of the match filter is calculated to obtain the noise reference value within a pre-determined period. The output value of the match filter and the noise reference value are compared. When the output value of the match filter is larger than the noise reference value, a valid power value is obtained according to the output value of the match filter. The valid power values are accumulated. Finally, a SNR is calculated according to the noise reference value and the accumulated valid power value at the end of the estimation period. Thereby, the signal quality of the wireless communication channel is estimated according to the SNR, and the signal transmission rate is determined.

Abstract: An apparatus and method for detecting a signal in a communication system using multiple antennas are provided. The apparatus includes an optimal orderer for determining an order of signals that are subject to detection, a controller for controlling a parallel successive interference canceller so as to successively detect the signals according to the determined signal detection order, cancel the successively detected signals from a received signal, detect the signals in reverse order of the signal detection order, and cancel the successively detected signals from the received signal, and outputting a last detected signal and the parallel successive interference canceller for successively canceling the detected signals from the received signal according to a control of the controller. Accordingly, the invention provides a signal detection apparatus and method that improve the reliability while reducing the complexity of a communication system using multiple antennas.

Abstract: In contrast to prior are solutions that conduct an averaging operation to estimate metrics related to a communications channel such as a signal-to-noise ratio, the present invention selects a particular value such as a minimum, maximum, or median value from a distribution of values collected over a selected interval. Selecting a particular value from the distribution of values facilitates a more accurate characterization process and increased data throughput. To reduce the processing burden associated with selecting a particular value, the present invention provides a set of cascaded value selection queues that each selects a particular value from the queued values such as a minimum value. The cascaded queues are also successively sub-sampled to reduce the computing resources required to characterize the communications channel. The estimated metrics resulting from the above-described process may be used to adjust the data encoding process and increase data throughput on the communications channel.

Abstract: A tracking apparatus and method in a mobile terminal are provided. The method includes extracting an on-time energy signal, an early energy signal, and a late energy signal from a received signal, estimating respective ICI components from the early energy signal and the late energy signal, measuring an early energy and a late energy by using the early energy signal and the late energy signal, and removing ICI by subtracting the estimated ICI components respective from the measured early energy and late energy.

Abstract: Synchronization between a transmitter and a receiver with respect to the boundary of higher-layer logical data structures is improved by considering both the statistical likelihood of the value of a transmitted boundary indicator and the quality of the channel during the transmission. A boundary indicator received under poor channel quality, that is decoded to a statistically unlikely value, is suspect and one or more retransmission is requested. A reliable value of the boundary indicator is a retransmitted boundary indicator received during good channel conditions; the value of two boundary indicators received successively, both under poor channel conditions, that decode to the same value; or a majority vote of three successive boundary indicators, the first two received under poor channel conditions. The accuracy of the received boundary indicator is increased, at a cost of one, or at most, two, retransmissions.

Abstract: An apparatus and method for estimating a Signal to Interference plus Noise Ratio (SINR) in a wireless communication system are provided. The method includes processing a received signal by Orthogonal Frequency Division Multiplexing (OFDM) demodulation to convert the received signal into frequency-domain data, selecting ranging data from the frequency-domain data, multiplying the selected ranging data by a ranging code to perform code demodulation, calculating at least one norm value and at least one coherent norm value by bundle for the code-demodulated data and estimating an SINR using the calculated at least one norm value and at least one coherent norm value.

Abstract: A reception quality estimation device includes: a correlation extractor for extracting correlation between multiplexed reception reference signals received from the plurality of user terminals and a predetermined reference signal sequence, wherein extracted correlation corresponds to each user terminal; a received power calculator for calculating received signal power from the extracted correlation corresponding to each user terminal; a total received power calculator for calculating total received signal power by summing up the received signal power for all the plurality of user terminals; a noise power estimator for estimating noise power based on the total received signal power and total received power of multiplexed reception reference signals; and a reception quality calculator for calculating the reception quality of each user terminal based on the received signal power and the noise power.

Abstract: A method involves performing a plurality of acts. The acts include transmitting a first signal stream to a first channel of a multi-channel communications medium while transmitting a second signal stream to a different second channel of the medium. The second signal stream is substantially temporally correlated to the first signal stream. The method includes receiving an SINR measured at a receiver configured to receive signals from the first channel. The SINR is measured while the receiver received the first signal stream. The method includes determining a channel matrix element between the first and second channels or a ratio of said channel matrix element to a diagonal element of the channel matrix. The act of determining is based on the received SINR.

Abstract: Provided is a transmitting/receiving apparatus and method for an IDMA system. The receiving apparatus includes a channel estimator, an estimator, and a determiner. The channel estimator estimates a channel using a multi-user signal received through at least one RX antenna. The estimator estimates the noise power and the signal power for each transmission layer of each user by using the estimated channel value from the channel estimator. The determiner determines the number of transmission layers for each user and an MCS level for each transmission layer by using the signal power and the noise power estimated by the estimator.

Abstract: A system estimates noise power in a scalar, multi-signal communications channel. A data sampler collects N data samples from communications signals received from the communications channel. A module forms a covariance matrix of the N data samples based on a model order estimate. A module also computes the eigenvalue decomposition of the covariance matrix and ranks resultant eigenvalues from the minimum to the maximum for determining the noise power.

Abstract: A communications system includes a transmitter that transmits a modulated signal having encoded communications data over a communications channel. The transmitter adjusts one of at least modulation and coding at the transmitter based on the received channel state information of the transmitted signal. A receiver determines received signal metrics from the modulated signal. A noise power estimator estimates the noise power of the received communications signal by collecting N data samples from the communications signals, forming a covariance matrix of the N data samples based on a model order estimate, computing the eigenvalue decomposition of the covariance matrix and ranking resultant eigenvalues from the minimum to the maximum for determining the noise power of the received signal. At least one of modulation and coding are adjusted based on the monitored link quality of the communications channel to enhance use of the available channel capacity.

Abstract: A biasing algorithm, apparatus and method for detecting and modulation format of a received signal used in a mobile phone system implementing EDGE technology that transmits and receives both GMSK and 8PSK modulated signals. The biasing method and apparatus may also estimate the modulation format of bursts of data blocks of a received signal using information gathered and/or results determined during the modulation detection of one or more previous bursts of a data block to bias the modulation detection of a present burst of the same data block. The gathered information during the modulation detection of a previous burst includes either the signal-to-noise ratio or the noise energy information of the previous burst.

Abstract: In a wireless system comprising at least one transceiver configurable for communication over a wireless communication channel, the transceiver comprising a transmitter and a receiver, a method for controlling a data transmission rate of the at least one transceiver comprises the steps of: (i) determining a signal quality characteristic corresponding to a signal received at the receiver by measuring a difference between one or more reference constellation points and one or more received constellation points, the signal quality characteristic representing an estimation of signal degradation; and (ii) modifying a data transmission rate of the transmitter based, at least in part, on the signal quality characteristic.

Abstract: A link adaptation system using a Doppler frequency is provided. The link adaptation system includes: a Doppler frequency estimation unit to estimate a Doppler frequency of a signal transmitted via a wireless channel; a Signal to Noise Ratio (SNR) measurement interval determination unit to determine an SNR measurement interval of the signal transmitted via the wireless channel based on the estimated Doppler frequency; and an SNR measurement unit to measure an SNR of the signal based on the determined SNR measurement interval.

Abstract: Removing noise and interference from a signal by calculating a joint time-frequency domain of the signal, estimating instantaneous frequencies of the joint time-frequency domain, modifying each estimated instantaneous frequency, if necessary, to correspond to a frequency of the joint time-frequency domain to which it most closely compares, redistributing elements within the joint time-frequency domain according to the modified instantaneous frequencies, computing a magnitude for each element in the redistributed joint time-frequency domain, plotting the results, identifying peak values, eliminating from the redistributed joint time-frequency domain elements that do not correspond to the peak values, identifying noise and interference in the peak values, eliminating the noise and the interference from the redistributed joint time-frequency domain elements, and recovering a signal devoid of noise and interference from the modified redistributed joint time-frequency domain.

Abstract: A method and transmitter receiver sets are used to perform communication in digital subscriber line technology. The method includes: acquiring communication performance parameter; the first transmitter receiver set and the second transmitter receiver set using the predetermined communication standard to perform communication when the communication performance parameter is equal to the predetermined value or greater than the predetermined value, the predetermined communication standard is respectively set in the first transmitter receiver set and the second transmitter receiver set. The bit table and the gain table predetermined are respectively stored in the first transmitter receiver set and the second transmitter receiver set. According to the method, a rapid switch to the bit table and the gain table predetermined using simple message or enquiry answer mechanism may be ensured when great wideband noise exists. There is no need of interchanging the bit table and the gain table when using this method.

Abstract: A receiving station apparatus controls a number of null carriers included in a transmission signal transmitted by a transmitting station apparatus in a communication system adopting a multicarrier modulation system to suppress inter-carrier interference by using the null carrier. For example, a reception-quality measuring unit measures a reception quality of a subcarrier group forming the transmission signal, and a number-of-null carriers determining unit determines the number of null carriers included in a next transmission signal based on the reception quality.

Abstract: A method to process DP bits within a WCDMA receiver where a noise estimation that may be implemented within hardware is provided for improved flexibility and performance. DPCH pilot symbols are received, quantized, channel compensated and combined. The computation of an SNR estimate based on the combined DPCH pilot symbols is provided. Noise estimation is used as part of the SNR estimation of the DP bits (used for downlink power control). This method does not rely on the assumption that the channel is constant over the DP field, while prior methods did.

Abstract: Methods and apparatus to perform and/or analyze communication channels are described. In one embodiment, a test signal may be generated and transferred using a first signal route to a line-under-test in response to line qualification mode. The first signal route may include a compensation device to modify the test signal. In some embodiments, a reflected signal from the line-under-test may be received in response to the test signal. A second signal route may be utilized to route the reflected signal in response to line qualification mode.

Abstract: A system and method of estimating radio frequency (RF) background noise in a radio receiver system comprises determining a total receiver front-end noise based on a noise equivalent receiver bandwidth; estimating external noise associated with the radio receiver system; determining internal noise associated with the radio receiver system from a known noise value; combining the external noise with the internal noise; determining an absolute external (RF) background noise floor associated with the radio receiver system; estimating an out of band noise contribution based on radio receiver selectivity and known received noise levels of out of band sources; and generating a (RF) noise estimate in the radio receiver system based on the above steps. The invention utilizes the (RF) noise estimate to form a (RF) receiver signal to noise ratio enabling an estimate performance of (RF) radio links in the radio receiver system operating in a benign and hostile (RF) environment.

Abstract: Provided are an apparatus and method for measuring a carrier-to-interference and noise ratio (CINR) using a pilot symbol in a digital communication system, and more particularly, to an apparatus and method for measuring a CINR by estimating a data signal, noise, and an interference signal from a pilot symbol in a digital communication system using orthogonal frequency division multiplexing (OFDM)/orthogonal frequency division multiplexing access (OFDMA). The apparatus includes: a pilot symbol acquisition unit for acquiring the pilot symbol from a baseband frequency signal; a signal estimation unit for estimating a pilot signal and a data signal from the pilot symbol; a power calculation unit for calculating a power value of the estimated data signal and calculating a power value of a noise signal from a difference between the pilot symbol and an estimated pilot signal; and a CINR calculation unit for calculating a CINR on the basis of the power values of the data and noise signals.

Abstract: A system for measuring inter-carrier interference (ICI) in an OFDM system includes a test symbol generator coupled to a transmitter of the OFDM system to generate an N*N orthogonal matrix having N*N test symbols, and to send the test symbols in a test symbol stream via the transmitter to a receiver of the OFDM system. The N*N test symbols are arranged by the test symbol generator into an N*N orthogonal matrix before being sent to the receiver. The system also includes an ICI measuring module coupled to the receiver to detect the N*N test symbols received in the receiver and to arrange the test symbols as a receiving matrix in the same way as the orthogonal matrix in the transmitter. The ICI measuring module outputs the receiving matrix as an ICI matrix of the OFDM system, wherein an element on the kth row, lth column of the ICI matrix represents interference from the lth sub-carrier on the kth sub-carrier, wherein k?l.