Abstract: A method of transmit power control to allow a transmission side to execute transmit power control so that a signal to interference ratio (SIR) measured at a reception side is matched with a target SIR, the method includes digitizing a reception environment at the reception side, and setting the target SIR corresponding to an error rate of reception data for each of the reception environments; and changing the target SIR in accordance with the reception environment measured at the reception side or the reception environment selected at the reception side.

Abstract: Methods and apparatus to control transmission of a multicarrier wireless communication channel through multiple antennas is generally described.

Abstract: In a method of multipath acquisition for a dedicated traffic channel, path positions of the traffic channel that have desired signal energy for processing in a base station receiver may be determined as a function of information contained in a data part of the traffic channel.

Abstract: A rake receiver for processing a multi-path input signal received from a communications channel, wherein each multi-path component of the multi-path input signal comprises one or more symbols, comprises a plurality of fingers and a demodulator. Each of the plurality of fingers is adapted to receive the multi-path input signal and provide a sequence of input samples corresponding to a multi-path component of the multi-path input signal. The demodulator is adapted (i) during a single clock period, to receive and process one or more input samples corresponding to only one of the fingers, (ii) for each of the fingers, to accumulate multiple processed input samples to form a symbol, and (iii) to provide the formed symbols for all fingers.

Abstract: A subset of modeled impairment correlation terms are selected for use in received signal processing. According to one embodiment, a subset of modeled impairment correlation terms is selected and a composite impairment correlation term is determined based on the subset of modeled impairment correlation terms. The composite impairment correlation term may be determined by scaling the modeled impairment correlation terms included in the subset by respective model fitting parameters. The scaled modeled impairment correlation terms are then combined to form the composite impairment correlation term. The subset of modeled impairment correlation terms may be selected based on their respective model fitting parameters. In one embodiment, the modeled impairment terms having a model fitting parameter that satisfy a threshold are included in the subset while those that do not are excluded. The composite impairment correlation term may be used for received signal processing, e.g.

Abstract: In an orthogonal frequency division multiplexed (OFDM) system, a transmitter and/or receiver communicate separate data streams on non-orthogonal spatial channels. Each spatial channel may use the same set of OFDM subcarriers and may take advantage of the multipath characteristics of the spatial channel allowing the communication of additional data without an increase in frequency bandwidth. Space-frequency subcarrier modulation assignments may be dynamically assigned on a per subcarrier basis as well as a per spatial channel basis to help maximize the data-carrying capacity of the channel. In some embodiments, each of the spatial channels may be associated with one of a plurality of spatially diverse antennas. In other embodiments, beamforming may be performed to allow the transmission and/or reception of signals within the spatial channels.

Abstract: An apparatus and method for adjusting a desired expression section according to input bit values in a mobile communication system that expresses only a defined partial section of the input bit values in order to make the number of output bits be less than the number of the input bits, and maps bit values included in unexpressed sections to a specific value is provided. In the apparatus and method, a measurer divides possible output bit values into at least three sections, and measures output frequencies of output bits for the respective sections for a predetermined time. A controller adjusts the desired expression section, when an output frequency for a specific section is greater than output frequencies for other sections.

Abstract: Provided is a high resolution distance ranging apparatus using an ultra-wideband (UWB) communication. The apparatus includes: a first spectrum analyzer for extracting a frequency component corresponding to multipath time delay from a reception signal; a second spectrum analyzer for acquiring a noise subspace of the extracted frequency component and extracting a frequency component where maximum power is located from a frequency spectrum based on the noise subspace; a time of arrival (TOA) extractor for extracting TOA based on the frequency component where maximum power is located.

Abstract: A network entity and method for eliminating ranging collisions for a group call in a communication network includes a step 300 of provisioning a pre-established rule for all members of a group, the rule including a common random number generator seed. A next step 302 includes initiating a group communication to subscriber units belonging to a group. A next step 304 includes generating a list of unique ranging codes for the members of the group using the common seed. A next step 306 includes each member of the group transmitting on its unique ranging code.

Abstract: A method and apparatus is disclosed for performing a multi-equalization of a transmitted signal on a channel having varying characteristics comprising equalizing the transmitted signal using a plurality of setting defining a plurality of equalizing functions to provide a corresponding plurality of symbol signal, synchronizing each of the plurality of symbol signals to provide a plurality of synchronized signals, selecting at least one of the plurality of synchronized signals according to at least one transmission performance criterion and providing the selected one of the plurality of synchronized signals.

Abstract: In a MIMO delay spread (OFDM) system or a MIMO single carrier (non-OFDM) system wherein a transmitter transmits signals to a receiver through multipath fading channels, an equivalent frequency-domain MIMO multipath channel matrix is used to estimate the maximum mutual information regarding the relationship between transmitted signals and received signals. It is possible to compute the upper bound of the maximum mutual information at least based on the total energy of all resolvable paths in the fading channels. The upper bound or the changes in the upper bound can be used to adjust the transmission parameters used in data transmission. The transmission parameters include the modulation order in the modulation process, the code rate and the puncturing rate.

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 system and method for estimating a channel in a wireless receiver is disclosed. The method preferably applies to a communication system using the OFDM standard. The method comprises receiving a block of “n” transmitted symbols, the symbols including pilot symbols and “d” data symbols, estimating a channel using the pilot symbols to create a channel estimate, choosing a group of “m” strongest symbols from the “d” received symbols, compensating the “m” strongest symbols using the channel estimate to create a group of “m” compensated symbols, re-estimating the channel using the group of “m” compensated symbols and pilot symbols; and either (1) repeating the steps of choosing a group of “m” strongest symbols, compensating the group of “m” strongest symbols and re-estimating the channel, or (2) using a latest channel estimate to compensate all symbols within the block.

Abstract: A Doppler compensation method is used for radio transmission between a mobile body possibly but not exclusively a train and some base station, both mobile body and base station comprise respectively a transceiver connected to an antenna for the radio transmission. The method comprises the step of determining the direction of motion of the mobile body with respect to the active base station i.e. the base station to which a radio transmission link is just built. The method is then followed by the step to apply a constant Doppler compensation corresponding to the cancellation of the Doppler effect for a mobile body moving in the same direction at predefined limiting speed of motion (vlimit) at which a quality threshold is reached with the used radio transmission technology in the case without a Doppler compensation.

Abstract: A method for calibration of RF paths of a frequency hopping adaptive base transceiver station is provided. The method of calibration calibrates a wireless cellular telecommunication system with a frequency hopping adaptive base transceiver station including an adaptive antenna array with two or more RF traffic transceiver apparatus chains. The wireless cellular telecommunication system communicates with mobile units on a frequencies defined by a hop list. The method of calibration includes the step of periodically interrupting a frequency hopping process of the frequency hopping adaptive base transceiver station while calls are in progress. The method of calibration further includes the step of calibrating an antenna transmit path for a RF traffic transceiver apparatus chain at a frequency selected to include one or more frequencies in the hop list to determine a set of weighting parameters for the antenna transmit path at the one or more frequencies.

Abstract: In an RF communication system, aspects for diversity processing may comprise processing a plurality of received multipath signals as clusters of signals. The received multipath signals may be diversity signals received from diversity transmit antennas at a base station. Timing information may be generated for tracking the clusters of signals. Complex phase and amplitude information may also be estimated for at least some of the multipath signals in the clusters of signals. At least a portion of the received multipath signals may be combined to form a single path processed diversity signal. A plurality of the single path processed diversity signals may be combined together, where each of the single path processed diversity signals may be derived from one of the plurality of diversity transmit antennas at the base station. The diversity signals may be transmitted via at least one of a plurality of diversity modes.

Abstract: A method and apparatus for processing received wireless communications are provided. Power delay profiles (PDPs) including PDP elements are processed. Less than half of the PDP elements of each PDP are selected. The selected PDP elements are combined based on position, and the combined PDP elements are qualified for further signal processing to determine a received signal path associated with the PDP.

Abstract: A mobile communication device comprises a plurality of spatially and/or polar diverse antenna configurations. Signals received by each of the plurality of antenna configurations are combined in a combiner and passed to a rake receiver that can be configured to combine the signals received by each of the plurality of antenna configurations for further processing. The mobile communication device can comprises a signal adjusting network that can be configured to adjust the phase and/or magnitude of signals being received by one of the antennas.

Abstract: A Node-B/base station has an access burst detector. The access burst detector comprises at least one antenna for receiving signals from users and a pool of reconfigurable correlators. Each correlator correlates an inputted access burst code at an inputted code phase with an inputted antenna output. An antenna controller selectively couples any output of the at least one antenna to an input of any of the correlators. A code controller provides to an input of each correlator an access burst code. The code controller controls the inputted code phase of each controller. A sorter/post processor sorts output energy levels of the correlators.

Abstract: An OFDM receiver apparatus mounted on a movable object for receiving an OFDM signal, includes a plurality of directional antennas which receive an OFDM signal, an estimator to estimate a center frequency of a spectrum of a Doppler component from one of the received signals or a multiplexed signal obtained by multiplexing the received signals, a shift quantity calculator to calculate a shift quantity from the estimated center frequency of the estimator and directivity information representing directivity directions of the directional antennas, a plurality of frequency shifters to subject the received signals to frequency shift according to the shift quantity to compensate for Doppler shift, a combining unit to diversity-combine frequency shifted signals of the frequency shifters, and a demodulator/decoder to demodulate and decode combining diversity signals of the combining unit.

Abstract: Techniques to control an optical receiver having a control loop using Bit Error Rate (BER). In one implementation, a bit error rate (BER) associated with a received optical signal is determined. Indication of the BER to a control loop adapted is provided to adjust the optical signal in a manner tending to reduce the BER. The received optical signal is adapted in a manner tending to increase the BER such that the control loop operates within an active control region.

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: A method for operating a mobile equipment (ME 10) in a wireless network (12) includes receiving from a wireless network a parameter that is indicative of a signal quality experienced by the ME, such as by determining a speed of the ME; calculating in the ME an indication of link quality, the calculation employing a filtering operation having a filter length that is a function of the determined parameter, such as speed or derivative of the speed of the ME; and reporting the calculated indication of link quality to the wireless network. The wireless network derives an indication of ME speed and transmits the speed indication to the ME using a point-to-point message.

Abstract: A method for remote crosstalk cancellation, includes: the combination transmitting signal is performed a pre-coding of crosstalk cancellation in the manner of self-adapting filtering, the self-adapting changes of the values of filtering parameters are guided correctly with the influence of the crosstalk component in the received signals which is reflected indirectly by relevant values of the noise statistic reported by the receiver. A corresponding device and a signal processing system for remote crosstalk cancellation are provided. The self-adapting adjustment of the values of filtering parameters has a favorable astringency and an effect for crosstalk cancellation, avoiding the need to know the channel transmission matrix in advance, while absolutely avoiding the conflict to the existing transmission standard.

Abstract: A mobile communication system receives a reception signal, and determines a first error value by using a first scheme, and a second error value by using a second scheme, and determines a first scheme application weight according to a difference between the first error value and the second error value, and a second scheme application weight according to the difference between the first error value and the second error value, and generates a third error value using a scheme that combines the first scheme to which the first scheme application weight is applied and the second scheme to which the second scheme application weight is applied, and determines a reception beam weight using the reception signal, the third error value, and an output signal generated by applying the reception beam to the reception signal, wherein the reception beam weight is used for generating the reception beam.

Abstract: A space-time multiuser detector simultaneously reduces multiple access interference (MAI) and multipath channel distortion (MCD) that are disadvantages of mobile communication systems. The space-time multiuser detector includes a plurality of receiving antennas; a channel estimator which estimates signals received via the receiving antennas; a space-time diversity decoder which performs space-time decoding with respect to the signals provided from the channel estimator and performs diversity combination; a signal aligner which aligns the signals provided from the space-time diversity decoder; and a successive interference cancellation detector which generates an interference signal from the signals that are provided from the signal aligner one by one in sequence, and removes the interference signal from the received original signals.

Abstract: In a wireless communication system the receiver includes a first plurality of receive chains and a second plurality of antennas. Each receive chain is selectively connectable to selected antennas. The antennas are selected based on criteria obtained from a received RF signal to produce an antenna configuration connected to the receive chains to reduce RF fading at the receiver. An electronic switch connects the antennas to the receive chains. The receiver is programmed to determine which antenna should be connected to each receive chain by the switch by measuring characteristics of the received signal for each allowed antenna configuration and selecting the best antenna configuration. Transmitters may be similarly configured.

Abstract: A rake receiver for processing a multi-path input signal received from a communications channel, wherein each multi-path component of the multi-path input signal comprises one or more symbols, comprises a plurality of fingers and a demodulator. Each of the plurality of fingers is adapted to receive the multi-path input signal and provide a sequence of input samples corresponding to a multi-path component of the multi-path input signal. The demodulator is adapted (i) during a single clock period, to receive and process one or more input samples corresponding to only one of the fingers, (ii) for each of the fingers, to accumulate multiple processed input samples to form a symbol, and (iii) to provide the formed symbols for all fingers.

Abstract: In an MIMO mobile communication system allowing a PDMA base station to communicate with a single terminal through a plurality of paths the terminal and the base station are each responsive to information of communication quality of a spatial path detected as having a reception error to appropriately control switching the path's communication operation between a plurality of types of operations. In a first operation, only a single path remains and the other paths are disconnected. In a second operation, path diversity is effected. In a third operation, path's modulation level is reduced. These operations are performed by a DSP. If in the MIMO system paths' mutual interference occurs the terminal and base station can still maintain connection.

Abstract: A receiver is described herein that is capable of receiving and processing a radio signal and further capable of using interpolation to initialize receiver parameters when there is a change in at least one delay associated with the received radio signal or when there is at least one new correlator position. For instance, the receiver parameters that can be initialized include: (1) channel coefficients; (2) AFC parameters; (3) tracking parameters; (4) noise statistics (noise correlations); (5) signal statistics (channel coefficient correlations); (6) data statistics (despread values or chip samples); or (7) combining weights.

Abstract: The present invention describes a method of closed loop MIMO communication utilizing implicit or explicit channel state information (CSI) at the transmitter and the receiver. The transmitter performs linear pre-processing (for example, QR decomposition or bi-diagonal decomposition or Jacobi rotations, and/or sporadic SVDs) on a channel matrix, and the receiver mitigates the mutual interference between the streams by performing MMSE processing on the received signals. The MMSE matrix is computed with respect to the processed channel that may estimated by the receiver through preprocessed pilot signals. The transmitters preprocessing is of much lesser cost and complexity than full SVD.

Abstract: A system and method for generating transmit weighting values for signal weighting that may be used in various transmitter and receiver structures is disclosed herein. The weighting values are determined as a function of frequency based upon a state of a communication channel and the transmission mode of the signal. In variations, weighting of the weighted signal that is transmitted through each of a plurality of antennas is carried out with one of a corresponding plurality of transmit antenna spatial weights. In these variations, a search may be conducted over various combinations of transmit weighting values and transmit antenna spatial weights in order to find a weight combination that optimizes a performance measure such as the output signal-to-noise ratio, the output bit error rate or the output packet error rate.

Abstract: A pilot extract section 14 extracts a pilot signal from received signal. An adder 21 in-phase adds a plurality of correlated values of pilot signals for respective subcarriers. Delay devices 201-1 to 201-6 temporarily maintain one in-phase added value. Multiplier 202-1 to 202-6 multiplies a predetermined coefficient to the in-phase added value that is output from the delay device. The predetermined coefficient reflects the result, which is obtained by correcting for multiple times the difference of channel variation in the different subcarriers that is generated when noise power per one subcarrier is calculated. Each of the multiplying results is added by an adder 24, and is squared by a square device 25. A cumulative adder 26 cumulative-adds the squared values for the whole subcarrier. A multiplier 203 averages by multiplying predetermined values to the cumulative-added values.

Abstract: A system and/or a method for detecting interference using correlation may be used in a communication system to protect against, or to report the presence of, narrowband interference, which has deleterious effects on the performance of the wideband communication system. The interference detection system described herein may be used to determine presence of narrowband interference by calculating correlation factors for a plurality of narrowband channels disposed within the wideband communication system and comparing the correlation factors with a threshold correlation factor.

Abstract: A rake receiver for processing a multi-path input signal received from a communications channel, wherein each multi-path component of the multi-path input signal comprises one or more symbols, comprises a plurality of fingers and a demodulator. Each of the plurality of fingers is adapted to receive the multi-path input signal and provide a sequence of input samples corresponding to a multi-path component of the multi-path input signal. The demodulator is adapted (i) during a single clock period, to receive and process one or more input samples corresponding to only one of the fingers, (ii) for each of the fingers, to accumulate multiple processed input samples to form a symbol, and (iii) to provide the formed symbols for all fingers.

Abstract: A multi-carrier communications apparatus which communicates between a first station and a second station as a destination station using a reference signal used for estimating a state of a channel, the multi-carrier communications apparatus comprising a multi-carrier modulator which modulates data on a plurality of subcarriers, a transmission unit configured to transmit the reference signal together with the data modulated to the destination station every subcarrier, and a control unit configured to control a reference signal transmission pattern according to a given communication condition, the reference signal transmission pattern including a transmission interval of the reference signal transmitted by the transmission unit.

Abstract: Aspects of a method and system for a single antenna receiver system for HSDPA are provided. Aspects of a method for processing RF signals, the method may comprise computing channel estimates based on a plurality of received individual distinct path signals, generating timing reference signals indicating a location of at least one of the plurality of received individual distinct path signals, combining at least a portion of the plurality of received individual distinct path signals as a signal cluster based on at least one of the computed channel estimates and said generated timing reference signals, and selecting at least one of combining and equalization processing based on at least one of the computed channel estimates and the generated timing reference signals. Aspects of a system for processing RF signals may comprise circuitry that selects at least one of combining and equalization processing based the computed channel estimates and/or generated timing reference signals.

Abstract: A method for transmitting and receiving weight information for creating transmission/reception beams in a mobile communication system using a multiple input multiple output adaptive antenna array scheme. The method includes a receiver receiving a predetermined signal, and differentially providing weights to a first scheme and a second scheme for minimizing an error between the received signal and a predetermined reference signal, thereby obtaining a minimum error value. The receiver generates a despread signal by despreading the received signal, produces a reception weight for creation of a reception beam by the receiver through calculation using the despread signal and the minimum error value, and produces a transmission weight for creation of a transmission beam by a counterpart transmitter through calculation using the reception weight and the minimum error value.

Abstract: A communication system for transmitting encoded signals over a communication channel is disclosed. The system includes a transmitter, which has a source that outputs a message signal. The transmitter also includes an encoder that generates a code word in response to the message signal. The code word has a construction that defines a plurality of paths associated with an intersymbol interference (ISI) environment of the communication channel, wherein the code word achieves a diversity based upon the number of transmit antennas and the number of ISI paths. Further, the transmitter includes a modulator that modulates the code word for transmission over the communication channel, and multiple antennas that transmit the modulated code word over the communication channel. The system encompasses a receiver that receives the transmitted code word via a number of receive antennas.

Abstract: An increase in the power consumption and deterioration of the reception characteristic which can arise as a result of installing a multi-path interference removing apparatus are suppressed. The multi-path interference removing apparatus is operated only in the following cases: a case where a mobile communication terminal is in a communication active state, a case where communication takes place via a base station to which the adaptive modulation and coding technology is applied, a case where the number of reception paths of the mobile communication terminal is two or more paths, a case where the speed of motion of the mobile communication terminal is 60 km/h or less, and a case where the Signal to Interference power Ratio is 8 dB or more.

Abstract: A signal-path-selection method in a RAKE receiver includes producing C channel estimates from M received signal paths, determining a plurality of best signal paths using the C produced channel estimates, choosing A signal paths of the plurality of best signal paths in accordance with at least one pre-determined criterion, and combining the A signal paths. C is a measure of channel-estimation capacity of the RAKE receiver. M is greater than C. This Abstract is provided to comply with rules requiring an Abstract that allows a searcher or other reader to quickly ascertain subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: In one embodiment of the present invention, a dynamic multi-path detection device is disclosed to include at least one narrow-band signal metric estimator responsive to input signal. Each of the at least one estimators measures a particular characteristic of the input signal in a frequency band that is narrower than the overall signal bandwidth and is operative to generate a signal parameter estimate signal. The dynamic multi-path detection device is further disclosed to include a signal metric comparison device responsive to the signal parameter estimate signal(s) and operative to generate a dynamic multi-path indication signal for detecting dynamic multi-path.

Abstract: Multipath relative channel estimations for weighting maximal ratio combining of RAKE detectors in wireless communication systems uses maximal eigenvectors of covariance matrices of path signals. Estimates for close-in and outlying sets of symbols provides linear time change channel estimation.

Abstract: A system and method for estimating a channel in a wireless receiver is disclosed. The method preferably applies to a communication system using the OFDM standard. The method comprises receiving a block of “n” transmitted symbols, the symbols including pilot symbols and “d” data symbols, estimating a channel using the pilot symbols to create a channel estimate, choosing a group of “m” strongest symbols from the “d” received symbols, compensating the “m” strongest symbols using the channel estimate to create a group of “m” compensated symbols, re-estimating the channel using the group of “m” compensated symbols and pilot symbols; and either (1) repeating the steps of choosing a group of “m” strongest symbols, compensating the group of “m” strongest symbols and re-estimating the channel, or (2) using a latest channel estimate to compensate all symbols within the block.

Abstract: A smart antenna device includes: first and second weighting units provided to correspond to two antennas disposed apart from each other so as to weight received signals inputted from the antennas, respectively; an operating unit that obtains a ratio of a weight of the second weighting unit to a weight of the first weighting unit; an adding unit that adds a signal outputted from the first weighting unit and a signal outputted from the second weighting unit to each other; and a phase shifting unit that makes phases of the two signals equal to each other.

Abstract: A transmission and reception apparatus and method for use in a wireless communication system, and an apparatus and method for adaptively transmit and receive a signal according to channel state in a wireless communication system. An apparatus for adaptively performing transmission according to a state of a channel transmitted from a transmitter to at least one receiver includes a signal to interference ratio estimator for estimating a signal to interference ratio of the channel using a signal transmitted from the at least one receiver; and an adaptive transmitter for transmitting data to the at least one receiver on a basis of the estimated signal to interference ratio.

Abstract: System and method for canceling crosstalk in high-speed communications systems. An embodiment comprises precomputing channel pulse responses for a set of communications channels in a communications backplane, precomputing channel signal responses for the set of communications channels in the backplane with a training sequence, estimating noise coefficients using receiver training and the training sequence, storing noise coefficients for each communications channel in the set of communications channels, and canceling noise in a received transmission of a data sequence using the stored noise coefficients. The regularity of the communications backplane enables the precomputing of various values, which reduces computational requirements. Furthermore, it is often the case that a victim receiver has access to the digital data that is being transmitted by its dominant crosstalking transmitters, thereby simplifying noise cancellation.

Abstract: In an orthogonal frequency division multiplexed (OFDM) system, a transmitter and/or receiver communicate separate data streams on non-orthogonal spatial channels. Each spatial channel may use the same set of OFDM subcarriers and may take advantage of the multipath characteristics of the spatial channel allowing the communication of additional data without an increase in frequency bandwidth. Space-frequency subcarrier modulation assignments may be dynamically assigned on a per subcarrier basis as well as a per spatial channel basis to help maximize the data-carrying capacity of the channel. In some embodiments, each of the spatial channels may be associated with one of a plurality of spatially diverse antennas. In other embodiments, beamforming may be performed to allow the transmission and/or reception of signals within the spatial channels.

Abstract: A method (10, 40 or 70) or system (200) of detecting periodic intermittent interference (PII) can include indirect detection by tracking (14) retransmission statistics of isochronous traffic or alternatively tracking channel probe request failures corresponding to temporal characteristics of microwave oven interference. Such tracking can be done in a number of ways including tracking (16) retransmission statistics by tracking MAC layer statistics or by tracking retransmission statistics for Voice over WLAN or by tracking a number of retransmission attempts required per transmission opportunity. In another alternative, the method can track (18) success and failures of probe requests for data traffic. The tracking schemes can use correlation. The method can further introduce (28) hysteresis in the detection of the PII to prevent rapid entering and exiting from a current detection mode. The method can further operate (29) in a direct PII detection mode if the indirect detection mode indicates PII.

Abstract: A device and a method at a mobile communication system which provide a flexible and realistic way of emulating the time dispersive qualities and the broadband frequency correlation qualities of a radio channel. The device includes two or more flexible delay modules, and each module is arranged to emulate a tap and a continuously varying tap attenuation can be attained to describe the variation of the radio channel over the time. The modules may be realized in SAW-technology, and continuously varying tap attenuation may be achieved by the utilization of PIN-diode attenuators.