Abstract: A method for exiting receiver processing in a FLO-EV receiver comprises receiving a communication signal comprising at least one received symbol, deriving a channel performance metric based on the received symbol, determining whether the metric exceeds a threshold, and when the metric exceeds the threshold, providing a logic signal to signal receiver processing cessation.

Abstract: A circuit includes a first Viterbi detector configured to generate a first estimate signal based on an equalized signal. The first estimate signal includes preliminary non-return-to-zero data estimates. A first filter is configured to generate a first filtered signal based on a preliminary decision signal. The preliminary decision signal is generated based on the first estimate signal. A second Viterbi detector is in communication with the first Viterbi detector. The second Viterbi detector is configured to generate a final decision signal based on a sum of (i) a delayed version of the equalized signal, and (ii) the first filtered signal, wherein the final decision signal comprises final non-return-to-zero estimates.

Abstract: A method and apparatus for measuring channel quality over which has been transmitted a sequence of symbols produced by encoding and constellation mapping a source data element sequence. A sequence of received symbols is received over the channel. The sequence of received symbols is de-mapped based on a first channel quality indicator previously transmitted to a transmitter of the sequence of symbols. The de-mapped symbols are decoded to produce a decoded output sequence. In some embodiments, the decoding may be based on the first channel quality indicator. The decoded output sequence is re-encoded to produce a re-encoded output sequence. The de-mapped symbols are correlated with the re-encoded output sequence to produce a second channel quality indicator. The second channel quality indicator is transmitted to the transmitter to adaptively select a type of mapping based on the second channel quality indicator.

Abstract: Methods and systems for reversing indexing signal option selections are disclosed. The signal options can be any of a variety of options that permit the establishment of a communication link, including modulation format, coding rate, precoding index and assigned subbands. The selected options can be represented as a vector and the index can be determined by employing a worth function for a particular selected vector element that is dependent on a selection occurrence count of the element and on an element position count of the element. In particular, the index can be the summation of worth function values for each selected element.

Abstract: Apparatus and methods for calculating constant amplitude zero auto-correlation sequences are disclosed. One method includes calculating an argument of trigonometric functions used for calculating a constant amplitude zero auto-correlation sequence based at least on additive recursion of an input sequence root constant and without multiplication by a variable. A constant amplitude zero auto-correlation sequence is then computed using a CORDIC algorithm configured to calculate trigonometric functions used in determining the sequence without performing multiplication operations and based on the calculated argument. The disclosed methods and apparatus may be applied, in particular, to efficiently computing Zadoff-Chu sequences in preamble detection in particular physical random access channels in Long Term Evolution LTE communication systems. By allowing computation of such sequences, memory requirements can be reduced.

Abstract: A method and corresponding apparatus are provided to reduce the complexity of calculations needed to determine the time of arrival of position reference signals transmitted from multiple cells. A scheduler determines at a given instance what portions of a search grid or search window to search. A timing estimation circuit operating under the control of the scheduler computes timing estimates and reports the timing estimates back to the scheduler. The scheduler uses the timing estimates reported by the detection circuit to scheduler subsequent searches of the search grid or search window.

Abstract: An adaptive time delay control system is provided for matching the propagation time delay between two samples of a signal traveling through two independent paths so that they can be coherently combined for additional signal processing functions such as cosite interference cancellers, adaptive interference cancellers and adaptive beam formers. The adaptive time delay control system and associated method advantageously provide improved continuous matching of the two channels over a wider adjustment range while preserving both convergence speed over the full range and minimum jitter upon convergence by using composite autocorrelation functions to control (adjusting) a matching time delay in one channel.

Abstract: A set of one or more receiver parameters is adjusted. It is determined whether to adjust the set of receiver parameters. In the event it is determined to adjust the set of receiver parameters, a new set of values is generated for the set of receiver parameters using a cost function (where the cost function does not assume a noise signal in a receive signal to have a particular statistical distribution) and the set of receiver parameters is changed to have the new set of values.

Abstract: A baseband processing module according to the present invention includes a multi-path scanner module. The multi-path scanner module is operable to receive timing and scrambling code information regarding an expected multi-path signal component of a WCDMA signal. Then, the multi-path scanner module is operable to identify a plurality of multi-path signal components of the WCDMA signal by descrambling, despreading and correlating a known symbol pattern of/with a baseband RX signal within a search window. The multi-path scanner module is operable to determine timing information for the plurality of multi-path signal components of the WCDMA signal found within the search window and to pass this information to a coupled rake receiver combiner module.

Abstract: An apparatus for receiving data in a communication system includes: a detection unit configured to calculate power values of a data packet and a ratio of the power values by using a preamble of the data packet in a received signal, and detect the data packet through the calculated ratio of the power values; a control unit configured to calculate a gain compensation value of the detected data packet, and perform an automatic gain control (AGC) on the detected data packet by using the gain compensation value; a compensation unit configured to calculate a DC offset in the received signal, and remove the DC offset from the received signal; and a demodulator configured to demodulate the AGCed data packet.

Abstract: Systems, methods, and other embodiments associated with preamble detection based on repeated preamble codes are described. According to one embodiment, an apparatus is provided that wirelessly receives a signal and calculates a differential output corresponding to a multiplication of the signal and a delayed version of the signal. A cross correlation is performed between the differential output and a known preamble pattern to produce a cross correlation output. A moving average calculation is performed on the cross correlation output to produce an average cross correlation. One or more peaks are detected in the average cross correlation when the average cross correlation has an amplitude greater than a threshold. When the one or more detected peaks meets predetermined criteria, the apparatus provides information about at least one of the detected peaks for subsequent signal processing.

Abstract: A communications system receiver incorporates a time-averaged DC component subtracter to subtract a time-averaged DC offset component from a received, processed signal. The time-averaged DC offset is selectably calculated from a moving average or a running average. The selection of the time-averaged DC offset can be done depending on whether the receiver operates in a frequency hop mode or not.

Abstract: A method and apparatus for detecting the presence of a signal in a frequency band using non-uniform sampling includes an analog to digital converter (ADC) (110) for sampling an analog input signal (105) to create discrete signal samples (115), an ADC exciter (120) for exciting the ADC to sample at non-uniform time periods, a digital filter (130) for converting the discrete signal samples into an energy versus frequency spectrum (300), and an energy comparator (140) coupled to an output of the digital filter. The energy comparator (140) detects the presence of any frequency bands exceeding an energy setpoint.

Abstract: A multi carrier signal is typically comprised of many equidistant sub-carriers. This results in periodicity of spectrum within the bandwidth of such a multi-carrier signal. An unknown multi-carrier signal with equidistant sub-carriers can thus be sensed together with its sub-carrier spacing by finding a discernable local maximum in the cepstrum (Fourier transform of the log spectrum) of the multi-carrier signal.

Abstract: A communication apparatus that can suppress an increase in circuit size and reduce influence of interference, includes reception array antenna elements, a reception digital beam forming (DBF) network that generates a reception beam signal for forming M reception beams using a reception signal, and reception filter banks (FBs) that generate frequency split reception beam signals obtained by frequency-splitting the reception beam signal. The communication apparatus includes an interference-source detecting unit that stores, for each reception beam, an interference candidate beam area estimated based on an initial reception beam characteristic, calculates, based on the frequency split reception beam signals, a reception spectrum, and calculates, based on the reception spectrum and a reception spectrum of a reception beam to the interference candidate beam area, an interference source area.

Abstract: Described embodiments recover timing data from a received signal. An analog-to-digital converter (ADC) generates a value for each sample of the signal at a sample phase. A phase detector selects a window of n received bit samples, where n is a positive integer. If the bit window includes any Nyquist patterns, the phase detector enables a bang-bang trap. The bang-bang-trap iteratively, for each bit transition between a first consecutive bit and a second consecutive bit in the Nyquist patterns, samples the received signal at a zero crossing between the first and second consecutive bits and determines the polarity of the bit transition. Based on the polarity of the bit transition and the sample value at the zero crossing, the bang-bang trap determines whether the sample phase of the bit sample for the second consecutive bit is correct. If the sample phase is incorrect, the bang-bang trap adjusts the sample phase.

Abstract: An adaptive beam steering control system suitable for multiple element systems is provided for coherently forming a beam and tracking a dynamic scenario of a rapidly fading environment. The adaptive beam steering control system and associated method advantageously provide improved continuous beam steering with a faster response time and higher precision than normally attainable by using the greater slope of the nulling error function to perform the beam steering function. Although reciprocity of nulling and beam steering is normally only true for a single pair of elements, the method of the invention extends the process to larger arrays of elements.

Abstract: A final NOCE (noise covariance estimate) for reducing noise in a first channel of a receiver with a plurality of antennas is calculated. A first raw NOCE for the first channel is calculated, wherein a raw NOCE for a channel is an initial estimate of the covariance of noise in that channel between the plurality of antennas. At least a second raw NOCE for a second channel is calculated. A metric using the first and second raw NOCEs is calculated. The metric is used to determine whether the second raw NOCE should be included in the calculation of the final NOCE.

Abstract: A communication circuit is provided which transmits an information bit string from a transmission unit to a reception unit. The transmission unit includes a first modulation circuit that modulates a first carrier wave by a start bit to generate a first frequency signal, a second modulation circuit that modulates a second carrier wave by the information bit string to generate a second frequency signal, and a transmission circuit that transmits the first and second frequency signals from a transmitting antenna. The reception unit includes a reception circuit that receives a signal from the transmission unit, a first detector circuit that detects a signal of the first carrier wave to demodulate the start bit, a second detector circuit that detects a signal of the second carrier wave to demodulate the information bit string, and a detection circuit that is synchronized by the start bit and reads the information bit string.

Abstract: A method of processing first and second corresponding signals having a delay therebetween. The method includes introducing a plurality of different delays between the first and second signals, successive delay amounts differing from each other by less than the interval between chip boundaries, and for each introduced delay, summing samples of the second signal which are obtained at the times of, at least, chip boundaries between bits of the first signal which have the same state, to obtain a value; thereby to obtain a representation of how the value varies according to the introduced delay, which representation contains a level change associated with an introduced delay which bears a predetermined relationship to the delay between the first and second signals.

Abstract: Disclosed is a digital broadcasting transmission/reception system having an improved reception performance and in a signal-processing method thereof. A digital broadcasting transmitter comprises a TS stream generator for inputting robust and normal packets having stuff bytes in predetermined positions and generating dual TS stream by inserting the robust packets between the normal packets; a randomizer for randomizing the dual TS stream; a stuff byte exchanger for replacing the stuff bytes of a randomized data streams from the randomizer to a predetermined known data; and an encoder for encoding a data streams to which the known data is inserted. Accordingly, the present invention detects the known data from a signal received from a reception side and uses the detected known data for synchronization and equalization, so that the digital broadcasting reception performance can be improved at poor multipath channels.

Abstract: Methods, apparatuses, systems, and architectures for providing fast, independent, and reliable retrieval of system data (e.g., metadata) from a storage system, which enables minimal degradation in the reliability of user data. Methods generally include encoding the system data at least twice, at least once independently and at least once jointly along with user data. Methods can also include decoding the system data first, and upon a decoding failure, jointly decoding the system data and the user data.

Abstract: A method of performing cell search includes receiving a primary synchronization signal (PSS) comprising a primary synchronization code (PSC) and receiving a secondary synchronization signal (SSS) comprising a first secondary synchronization code (SSC) and a second SSC, wherein the SSS includes a first SSS and a second SSS, the first SSC and the second SSC are arranged in that order in the first SSS, and the second SSC and the first SSC are arranged in that order in the second SSS. Detection performance on synchronization signals can be improved, and cell search can be performed more reliably.

Abstract: A decoder for underdetermined MIMO systems with low decoding complexity is provided. The decoder consists of two stages: 1. Obtaining all valid candidate points efficiently by slab decoder. 2. Finding the optimal solution by conducting the intersectional operations with dynamic radius adaptation to the candidate set obtained from Stage 1. A reordering strategy is also disclosed. The reordering can be incorporated into the proposed decoding algorithm to provide a lower computational complexity and near-ML decoding performance for underdetermined MIMO systems.

Abstract: In a multi-input multi-output communication system receiving signals transmitted through a plurality of transmission antennas by using a plurality of reception antennas, a matrix determining a position of a symbol to be detected from a received signal is calculated at a first symbol detection step, and from the subsequent step, a matrix at the current step is acquired through a simple relationship from the matrix calculated at the previous step to determine a position of a symbol to be detected.

Abstract: A method of demodulating at a receiver a plurality of symbols bk comprised in a e.g. UWB, received signal y(t), said receiver having knowledge of a time hopping sequence vector c of the transmitted signal, said method comprising the step of: generating a plurality of frequency-domain samples from the received signal y(t). It further comprises the steps of: from said plurality of frequency-domain samples and said time hopping sequence vector c, applying a coarse estimation stage (7) for identifying the beginning of a first complete symbol (formula A) in an acquisition interval; applying a stage for fine estimation (8) of the time delay (formula B) of each symbol bk, wherein k denotes the k-th symbol, by searching a relative maximum at which a signal energy distribution exceeds a certain threshold Pth; from said fine estimation of the time delay (formula B) of each symbol bk, demodulating (formula C) said symbols bk.

Abstract: An apparatus and method for reducing pilot overhead in a multi-antenna system are provided. The method generates postcodes and pre-codes for streams used to transmit signals to at least two receivers. The method allocates a pilot signal to at least one of the streams, and allocates an additional pilot signal shared by at least one of the streams. The method precodes the pilot signal allocated to at least one of the streams, the additional pilot signal, and data to be transmitted to each of the receivers, based on the pre-code for each of the streams, prior to transmission.

Abstract: A communication system includes: a transmitter adapted to transmit a synchronizing clock and serial data synchronous with the synchronizing clock over a line at low amplitude; and a receiver adapted to receive the serial data and synchronizing clock from the transmitter. The receiver includes an amplifier adapted to amplify the received synchronizing clock of low amplitude to restore the clock to its original amplitude, a latched comparator adapted to latch the received serial data in synchronism with a reproduction clock, and a phase-locked circuit.

Abstract: A method and apparatus generating one or more clock signals in a receiver employing decision-feedback equalization (DFE). A received signal is sampled by a data clock and a transition clock, generating a data sample signal and a transition sample signal, respectively. A DFE correction is performed by DFE circuitry on the data sample signal to generate DFE detected data bits. The transition sample signal is sliced using a weighted threshold value to generate transition data bits. One or more phase updates of the data clock and the transition clocks are in response to the DFE detected data bits and the transition data bits. The weighted threshold is calculated from at least one of the prior-received DFE detected data bits. In one embodiment, the DFE detection may also be dependent on an effective delay (?) of the DFE circuit in relation to the received signal baud-period, T.

Abstract: Seamless wideband support is afforded by utilizing split-band data streams. For wideband signals, the 8 kHz bandwidth is divided into a low band, with approximately 0-4 kHz bandwidth, and a high band, with approximately 4-8 kHz bandwidth. Narrowband functions and services operate on the low band, while wideband functions and services operate on both low and high bands.

Abstract: A carrier frequency offset (CFO) estimation and synchronization method and apparatus of an orthogonal frequency division multiplexing (OFDM) receiver receiving an OFDM modulated signal. The OFDM receiver's CFO synchronization method includes step (a) performing an initial CFO estimation pull-in step using double correlation, step (b) performing a coarse residue CFO estimate acquisition step using independent combination of the double correlation and auto-correlation, and step (c) performing a small residue CFO tracking step by using the double correlation. Aspects of the invention solves the problems in the related art that a CFO tracking range cannot be reliably used in practice when the CFO tracking range is too narrow and a CFO estimation error increases when the CFO tracking range is too wide.

Abstract: Two decoding algorithms are introduced for the decoding of multi-level coded modulation and other types of coded modulation involving component codes and interleaving operations. An improved hard iterative decoding (IHID) algorithm is presented that improves upon a hard iteration decoding technique by adding a stopping criterion. Also, a list Viterbi hard iteration decoding (LV-IHID) algorithm is presented that employs list decoding in conjunction with the IHID algorithm. Both of these decoding algorithms improve upon conventional multi-stage decoding by reducing the effective error multiplicity that is observed at the lowest coding level. It is demonstrated that the LV-IHID algorithm performs close to soft iterative decoding. The computational and delay complexity of the proposed decoding algorithms compare favorably with soft iterative decoding strategies. Also, a novel labeling strategy for MLC design is presented.

Abstract: A system including a magnitude measuring module, an energy normalization module, and a metric generation module. The magnitude measuring module is configured to measure magnitudes of real portions of differentially demodulated signals, wherein the differentially demodulated signals are generated by differential demodulation of signals received from a base station. The energy normalization module is configured to generate a sum of energies of a plurality of subcarriers included in the signals received from the base station. The metric generation module is configured to generate a plurality of metrics for a plurality of symbols included in the signals received from the base station. The metric generation module is further configured to detect, based on the plurality of metrics, a preamble symbol included in the signals received from the base station.

Abstract: A method and system of fine timing synchronization for an OFDM signal. The OFDM signal is coarse timing synchronized, generating a synchronization sequence and a CFR (Channel Frequency Response). The synchronization sequence is removed. A correlation coefficient of the correlation between the CFR applied to a number of carriers and the number of carriers with different window shifts is calculated. The largest window shift corresponding to a downsampling factor is indicated by the lowest correlation coefficient greater than a threshold. The CFR is downsampled by the downsampling factor, and an inverse FFT is performed on the downsampled CFR with a reduced number of calculations reduced by the downsampling factor, transforming the CFR into a CIR. A fine timing synchronization position is determined from the CIR and is utilized by an FFT unit within an OFDM receiver to accurately receive OFDM symbols of the OFDM signal.

Abstract: The invention relates to a method of estimating symbols carried by a digital signal that is received by a receiver over a communication channel (5), said symbols being multiplexed or orthogonal frequency sub-carriers. The inventive method comprises the following steps in relation to each symbol carried by the digital signal, consisting in: performing at least two transforms towards the frequency domain (8,9) on a portion of the received signal essentially corresponding to the symbol, said transforms being performed with a determined time lag (10) therebetween: estimating the parameters (r0, r1, . . . , rn, r?0, r?1, . . . , r?n) of the communication channel from pre-determined binary information contained in the digital signal; and estimating the symbol from a combination of the result of each of the transforms performed and the estimated communication channel parameters.

Abstract: A wireless receiver including receiving antennas, frequency-space transformers, noise wave removers, a back-end signal processor, a pattern detector, a broadcast interruption detector, and a back-end controller. The frequency-space transformers convert signals received by the antennas into frequency-space signals. The noise wave removers each at least perform the calculation of a transmission line coefficient matrix and the calculation of an inter-antenna covariance matrix on the frequency-space signals. A controller controls the back-end signal processor to operate when the multicarrier transmission waves have been detected to be interrupted. The noise wave removers each perform the calculation of the inter-antenna covariance matrix when a broadcast interruption detector has detected the interruption of the multicarrier airwaves. Thus, the wireless receiver removes noise generated within it, thereby having high reception sensitivity.

Abstract: According to an embodiment, a receiver, system and method for channel estimation in a communications system utilizing multiple transmit antennas are provided. The receiver comprises an antenna node operable to receive a signal that includes a superposition of at least a first signal corresponding to a first sequence and a second signal corresponding to a second sequence; and a channel estimator, coupled to the antenna node, operable to correlate the received signal with at least one of the first and second sequences, to determine at least one boundary between at least two waveforms resulting from the correlation, and to calculate using the boundary and the at least two waveforms a first channel response corresponding to the first signal and a second channel response corresponding the second signal. Channel estimates are determined based on determined boundaries and may be smoothed by a Savitzky-Golay filter in the frequency domain. The variance of additive white Gaussian noise (AWGN) may also be estimated.

Abstract: A base station allowing mobile stations to efficiently remove interference signals. In this base station, an encoding part performs an error correction encoding of transport data to generate a bit sequence comprising systematic bits and parity bits; a repetition part repeats, as a repetition subject, only the parity bits out of the plurality of bits included in the bit sequence, which is generated by the encoding part, so as to perform a rate matching; a modulating part modulates, after the repetition, the bit sequence to generate symbols; an S/P part parallel converts the symbols serially inputted from the modulating part (103) and then outputs them to an IFFT part; and the IFFT part performs an IFFT processing of the symbols inputted from the S/P part and then maps them onto subcarriers in accordance with a predetermined mapping pattern, thereby generating OFDM symbols.

Abstract: Signal sequence detection techniques are provided to enable a wireless communication device to detect presence of a sequence, such as a preamble sequence, in the presence of other transmission that would otherwise interference with the ability of the device to detect the sequence. At the wireless communication device, energy in a frequency band is received and a receive signal is generated from the received energy. The receive signal is divided into windows of a predetermined time duration. A running auto-correlation of the receive signal is computed to produce an auto-correlation sequence for a sequence to be detected in the receive signal. Data representing a mask is generated for a window based on the receive signal. The mask is applied to the auto-correlation sequence to filter out portions of the auto-correlation sequence that are outside of the mask. A position of sequence, e.g.

Abstract: An apparatus for transmitting data using a plurality of carriers and method thereof are disclosed, by which PAPR improving effect is enhanced. A method of generating an OFDM signal, which is transmitted by spreading data symbols using a DFT (Discrete Fourier Transform) matrix, according to the present invention includes the steps of generating an output symbol by data-processing the data symbols in time domain in a manner of giving a specific weight to the data symbols and summing up the weight-given data symbols and generating the OFDM signal by performing OFDM data processing on the output symbol.

Abstract: A communication unit and wireless network operating at various bandwidths is disclosed. A signal having a first signal portion at a first bandwidth containing an indication of an operating bandwidth selected from a plurality of bandwidths used for a further signal portion is provided.

Abstract: Sub-microsecond time transfer in a GPS/GNSS receiver using a weak GPS/GNSS signal is provided. The digitized complex baseband signal and the generated PN code are cross-correlated for each code period so as to output a complex correlation value at each code epoch of the generated PN code, where a sequence of the output correlation values form a data stream representing the navigation message. Bit synchronization generates bit sync pulses at bit boundaries. The location of a target segment having a known sequence at a known bit location in the navigation message is detected by searching through a plurality of sub-frames and accumulating search results for the plurality of subframes. Transmission time of the target segment is determined from the detected location of the target segment, with a certain time ambiguity. Accurate local time is determined by solving the time ambiguity using approximate time obtained from an external source.

Abstract: Disclosed herein is a receiving apparatus including a first correlation value computation section, an operation section, a second correlation value computation section, a decoding section, and a determination section.

Abstract: Consumer infrared (CIR) systems typically are used in remote control systems. Most CIR systems expect a known carrier frequency and encoding scheme. However, there are many applications of a universal CIR receiver which can receive and decode CIR signals regardless of the carrier frequency or encoding scheme. A CIR receiver circuit is disclosed which can both decompose a received CIR signal into run length representation and detect the carrier frequency. The result can then be supplied to a host device for further processing, interpretation and/or actions.

Abstract: A method for the generation of a signal including a minimum of disturbances and noise is provided. A method for the detection of a signal including a minimum of disturbances and noise is also provided. An element of the signal is functionally dependent on at least one further element of the signal.

Abstract: A communication system includes a synchronizing signal generator that generates a synchronizing signal based on a timing of an alternating waveform in a power line, a data communicating circuit that performs the data communication, and a communication controller that controls to acquire a transmitting right utilizing a timing of the synchronizing signal and to control the communication circuit in accordance with whether or not the communication apparatus acquires the transmitting right.

Abstract: A data processing apparatus able to start decoding at a timing earlier than the conventional timing and able to reduce the storage capacity required for a storing means for storing the encoded data until a decoding side decodes the input encoded data in comparison with the conventional storage capacity, which apparatus selects frame data from frame data f(5) having the last decoding order to frame data f(0) having the first decoding order for processing for calculating a delay time min_delay and calculates the delay time min_delay. It calculates the delay time min_delay indicating the delay time from when the decoding side starts to receive input of the frame data to when the data is decoded based on the specified size and the bit rate of the input of the frame data to the decoding side for each of the frame data for processing.

Abstract: A system for processing a received signal having at least one code applied thereto, the received signal having a frequency, the system comprising: first correlator circuitry arranged to correlate the received signal with a first code to provide an output; second correlator circuitry arranged to correlate the received signal with a second code to provide an output, wherein the first code and the second code are different; and processor for processing together the outputs of the first and second correlator circuitry to cancel the frequency.

Abstract: A receiver includes a receiving unit that receives a signal from a satellite, a frequency conversion-discretization unit that converts the signal received in the receiving unit into an intermediate frequency signal of a frequency bandwidth including 0 Hz, and discretizes the frequency-converted intermediate frequency signal with a predetermined sampling frequency, a filter unit that filters the discretized signal, which is output from the frequency conversion-discretization unit, through a predetermined filter, a synchronization acquisition unit that acquires synchronization of a spreading code in the discretized signal filtered by the filter unit, and a synchronization holding unit that holds the synchronization of the spreading code, which is acquired by the synchronization acquisition unit.

Abstract: A mobile station (14) transmits a signal after connection is established, by using the same number of subcarriers as the number of subcarriers equal to or smaller than a predetermined number used for transmitting a connection request signal (TCCH). A base station (12) detects the number of subcarriers used for transmitting the connection request signal (TCCH) (S106), and controls in accordance with the detected number of subcarriers the passband width of a bandpass filter having a passband with a variable width accommodating the predetected number of subcarriers, for separating a signal of the mobile station (14) falling within the passband from a received signal (S108).