Abstract: A technique for converting a non-sectorized cell to a sectorized cell having multiple sectors utilizing a single broadband processing unit. The spectrum of a given frequency band having a center frequency ′&OHgr;o is divided into multiple bands (three, for example) having center frequencies ′&OHgr;o, ′&OHgr;o−&agr; and ′&OHgr;o+&agr;. In the receive path, respective sub-bands are used to convey analog RF signals from a subscriber in respective sectors to an associated transceiver. Each of the transceivers includes a front end for receiving incoming RF signals and an analog-to-digital converter for converting the analog signal to a digital data stream. The digital data streams from transceivers are combined, i.e., processed by digitally adding, and supplied to a single channelizer which, in turn, supplies the data to a TDM bus for transmission to a PSTN network.

Abstract: An apparatus (100) and method dynamically allocates radio frequency receive path resources as required by a programmable location engine (112). The programmable location engine (112) employs cascaded time of arrival and direction of arrival algorithms to determine per remote unit location data. The apparatus (100) employs a phased array antenna (104) and a programmable receiver switching apparatus (108). A plurality of radio frequency receivers (102a-102n) receive a plurality of different carriers, such as CDMA carriers, on each of a different phased array antenna element (106a-106d).

Abstract: In the conventional diversity reception, information included in each non-selected signal does not contribute to an improvement in the reliability of communications, and transmitting power has been dissipated to satisfy required communication quality. Owing to the setting of encoding in respective base stations to injection, signals each including the same contents, which are received by a mobile station, are used for increasing the reliability of communications without depending on the number of the signals which were capable of being received by the mobile station, to thereby reduce transmitting power for satisfying required communication quality.

Abstract: A proportional diversity radio system for mobile vehicles combats both short time delay multipath and long time delay multipath by mixing separate tuner signals obtained using separate space diversity antennas. The relative contribution of each tuner signal to a final mixed tuner output is determined in direct relation to their respective signal strength signals and inverse relation to their respective long time delay multipath noise signals.

Abstract: The present invention is a communication system having a plurality of forward channel communications and a plurality of corresponding reverse channel communications in a region for communications with cellular users. Each region includes a plurality of zone managers. Each zone manager includes a broadcaster having a broadcaster transmitter for broadcasting a plurality of forward channel communications using broadband broadcaster signals to form a plurality of broadcaster forward channels. Each zone manager includes an aggregator for processing reverse channel communications. Each zone manager communicates with a collector group for receiving reverse channel communications from users and forwarding reverse channel communications to the aggregator. Each of the users includes a user receiver for receiving a different forward channel from said broadcaster and includes user transmitter means for broadcasting user reverse channel communications in a different user reverse channel.

Abstract: In a direct sequence/code division multiple access (DS/CDMA) type interference canceller receiving apparatus having a delaying unit for delaying a reception signal into zeroth through (N−1)-th delayed signals, zeroth through (N−1)-th path receivers for demodulating the zeroth thorough the (N−1)-th delayed signals into zeroth through (N−1)-th demodulated signals, and a combining unit for combining the zeroth through the (N−1)-th demodulated signals into a combined signal, an n-th path receivers includes an n-th follow-up path detection unit for detecting an n-th follow-up path for the n-th path receiver on the basis of a peculiar spread code in response to an n-th coefficient control signal. The n-th follow-up path detection unit produces n-th follow-up path information indicative of the n-th follow-up path.

Abstract: A wideband radio receiver provides a complex baseband signal by normalizing an IF signal using a limiting amplifier. The normalized IF signal is applied to a complex sampling circuit to provide normalized I and Q components. The limiting amplifier provides an RSSI signal representing the received signal amplitude. The RSSI signal, which is sampled at the same rate as the normalized IF signal, is combined with the normalized I and Q components, to provide I and Q components of the baseband signal.

Abstract: Method and apparatus for completely suppressing interference vectors in a DS-CDMA communication system (100). Receiver circuits (122, 124, 126, 128) are assigned (404, 406) to multipath from sectors both in soft handoff and not in soft handoff with the receiver. For each receiver circuit, a set of traffic channels present on the sector's signal is determined (410). For each receiver circuit, the interference is ranked (412) according to predetermined interference criteria. A set of interference vectors is selected (414) from the ranked lists of interference and an orthogonal projection is computed (416) of the receiver's desired code or Walsh code relative to the selected set of interference vectors. The receiver circuit then uses the orthogonal projection in its correlator to despread (418) received data.

Abstract: A diversity path signal combiner includes two orthogonalizers which produce, from two received signals, two sets each of two relatively orthogonalized signals. One orthogonalized signal of each set includes one of the two received signals multiplied by a normalization factor, and the other includes a signal derived from both of the received signals, multiplied by a normalization factor. The inputs to the two orthogonalizers are relatively interchanged. Two signal combiners adaptively combine the two sets of orthogonalized signals with respective weights, and a selector selects between the resulting combined signals to produce an output combined signal.

Abstract: A base transceiver station operating a sectorized cell of a cellular radio system operates a plurality of narrow uplink main receive beams, and one or a plurality of uplink diversity received beams. A scanning means scans each of the uplink main receive beams to locate a communications channel on the main uplink beams. A diversity receiver receives a diverse beam signal from the diverse beam(s), which is compared with a beam signal received from a main uplink beam, and the main beam signal from the main beam, or a diverse beam signal from the diversity antenna is selected, depending on the comparative signal to noise ratio and signal strength of the main beam signal and diversity beam signal.

Abstract: A diversity reception device which weights in proportion to the reception level and combines a plurality of reception signals, includes a phase demodulator for demodulating the phase of the reception signal, a converter to output the sine and cosine elements of the reception signal, a sine element adder to add up sine element of each reception signal, and a cosine element adder to add up cosine element of each reception signal. The converter fetches and outputs predetermined values on sine and cosine elements of the reception signal upon input of the reception signal's reception level and phase data that is sent from phase demodulator. Therefore, the present device does not require expensive electronic circuits and can be made of small digital circuits suitable for IC including a memory.

Abstract: A diversity receiver is disclosed with an object to improve deteriorated transmission due to fading even when frequency selective fading resulting from multipaths occurs in a propagation path. The diversity receiver is provided with two lines, each line comprising an antenna, an orthogonal detector, first sampling and quantizing means, second sampling and quantizing means, a serial-parallel conversion circuit, and a Fourier transform circuit. In each of the lines, a modulated signal transmitted from a transmitter is received and processed. In a diversity processing unit, optimal diversity processing for each subcarrier is performed using the received and processed signals in respective lines. In this manner, an improvement is made in deteriorated transmission quality due to multipath fading between the receiver and the transmitter for transmitting OFDM modulated signals.

Abstract: Detection outputs 103 and 104 of phase-detection sections 9 and 19 of two reception circuits are input to phase difference detection sections 10 and 20, respectively. A detection output 103 indicating an instantaneous phase amount of each symbol as each phase output of a QPSK received signal is converted into phase difference detection outputs 105 and 106 each indicating a difference between the respective symbols. The output is input to a combination process section 23 where amplitude signals 101 and 102 are operated as weighting factors and vector combination so as to obtain a combination signal.

Abstract: A wireless telecommunications system base station architecture is disclosed that supports receive diversity, sectorization, and radio pooling without the need for a sniffer radio or a switching matrix between the radios and the receive antennas.

Abstract: An RDS receiver having dual tuners and dual antennas operates in two distinct modes, a diversity mode and a non-diversity mode. Diversity mode is when both tuners are tuned to a signal with the same program audio content and the audio from both tuners is blended together in a manner to minimize the effects of multipath distortion. In non-diversity mode, a forcing circuit isolates the tuner output signals so that one tuner provides the audio output while the other can be retuned to any other frequency for purposes of gathering RDS data.

Abstract: A method and device in a communication system including a receiver having a plurality of receiving antennas for receiving a plurality of information bursts transmitted by at least one transmitting user device where the information bursts contain a number of data symbols and a pilot symbol sequence of content known at both the transmitting user device and the receiver. The method provides for computing a channel transfer function between the transmitting user device at each of the plurality of receiving antennas, by computing a simulated received pilot signal for each receiving antenna, computing an error signal between the simulated received pilot signal and the received pilot symbol sequence, computing a channel modeling sequence, wherein the power of the error signal is minimized, and computing the channel transfer function by weighting predetermined basis functions by the channel modeling sequence.

Abstract: A communication device employs a method and apparatus for amplifying a radio frequency (RF) signal that eliminates the need for a signal splitter. An RF input signal (202) is coupled to a first RF amplifier stage (206) only. A signal coupler (222) couples an output of the first amplifier stage (206) to an input of a second amplifier stage (208). The input signal (242) for the second RF amplifier stage is an attenuated version of the output signal (240) from the first RF amplifier stage. The outputs of the first and second RF amplifier stages (206, 208) are combined by a signal combiner (234) to produce a combined output signal (246) for transmission.

Abstract: A radio frequency (RF) circuit (300) includes two parallel sections (310, 312) that are designed to function collectively through the use of a signal splitter/switching circuit (200) and a signal combiner (314). To optimize the performance of the RF circuit (300), a switching arrangement (214, 216, 218, 220, 222, 224, 226, 228, and 230) that is part of the signal splitter/switching circuit (200) is used to separate and isolate the two parallel sections (310, 312) for tuning purposes. After each parallel section (310, 312) has been individually tuned, the two parallel sections (310, 312) are recombined for joint operation.

Abstract: A method and system for combining signals in a receiver employing antenna diversity. If the interference exceeds a predetermined threshold, interference rejection combining (IRC) is used. If the interference does not exceed the predetermined threshold, maximum ratio combining (MRC) is used. The diversity combining technique can be selected, and the signals combined every burst, half-burst, or other suitable interval.

Abstract: Disclosed is a delay detection demodulation system which has: a plurality of receiving systems; a plurality of instantaneous phase detecting circuits for detecting an instantaneous phase from the output of each of the plurality of receiving systems; a plurality of phase difference operating circuits for determining a phase difference in one symbol section from the output of each of the plurality of instantaneous phase detecting circuits; a combining circuit for combining the outputs of the plurality of operating circuits; a delay detection circuit for conducting error diffusion type delay detection after the combining of the combining circuit; and a demodulation logical circuit for conducting demodulation logical operation.

Abstract: Co-channel interference in an AMPS (Advanced Mobile Phone System) receiver, having at least two diversity paths each for producing a received signal, is reduced by determining weights for combining the received signals in dependence upon the received signals and a reference signal, combining the received signals in accordance with the determined weights to produce a combined received signal, demodulating the combined received signal, and producing the reference signal by amplitude limiting the combined received signal or modulating the demodulated signal or a signal derived from the demodulated signal, so that the reference signal is produced from the combined received signal with amplitude variations reduced and with frequency variations of the desired signal substantially maintained.

Abstract: A receiver and antenna selection system located at a base station preferably comprises a plurality of radio units, each connected to its own antenna. Each radio unit receives a radio message and independently derives quality metrics based on the reception quality of the radio message, as indicated, for example, by a received signal strength indication, cyclic redundancy check result, preamble correlation magnitude, and other factors. Each radio unit transfers the quality metrics as serial data to an antenna selector. The antenna selector, simultaneously for each radio unit, converts and formats the serial data into individual data words and/or bits corresponding to the quality metrics, then applies the data words and/or bits to an antenna scoring block for determining an antenna score for each antenna. A comparison block compares the antenna scores and selects the best antenna for reception and/or transmission.

Abstract: A space diversity, multiple-tuner radio receiver obtains substantially noise free reception under most signal conditions. The tuner outputs are mixed in proportion with the signal quality as determined by detecting noise in each tuner output signal. Long-time-delay multipath distortion, adjacent channel interference, and co-channel interference are reduced by selecting predetermined antenna pattern combinations in response to high noise levels being present from both tuners.

Abstract: A space diversity receiver apparatus receives signals by two spatially separated antennas, controls the phase of the signal received by one of the antennas by a phase control circuit, combines the phase-controlled signal and the signal received by the other antenna by a combiner and outputs the combined signal. A digital detector digitally detects the center frequency level and the levels on high- and low-frequency sides of the center frequency of the combined signal. Phase is controlled in such a manner that the center frequency level will coincide with a set level and a deviation between the levels on the high- and low-frequency sides of the center frequency will become zero.

Abstract: The connection between a plurality of antenna output signals and a plurality of finger units is switched in dependence upon a reception state of each multipath propagation path at each antenna branch to controllably select those finger units to be subjected to RAKE combination. A particular finger unit is excluded from RAKE combination if the reception state does not satisfy a predetermined condition.

Abstract: A delay spread is created in a digital radio signal to reduce the coherence bandwidth and facilitate frequency hopping to reduce the effect of fading losses within an enclosed propagation environment. The delay spread is introduced into the signal in several ways. One technique disclosed employs a transmitter with two separate antennas one of which transmits the digital signal and the other of which transmits the same signal after a phase delay has been introduced into the signal. The carrier frequency of the signals is hopped between at least two frequencies and the receiver processes the resulting signals. In another embodiment, a single transmit antenna is used but the signal is received by two different antennas with the output signal from one of those antennas being phase delayed before combining it with the other prior to processing by the receiver circuitry.

Abstract: A portable information terminal device with a radio selective-calling receiver including first and second receiver sections with first and second antennas, respectively, implements an improvement of the reception sensitivity deterioration caused by the noise of a personal computer attached to the device with any increase of the dissipation current generated by the receiver maintained at a minimum. Only when the portable information terminal device is connected to the personal computer will it operate in a diversity reception mode to implement both receiving sections, improving reception sensitivity deterioration. When the portable information terminal device is not connected to the personal computer, diversity reception is not implemented, thus permitting only one of the receiving sections to receive.

Abstract: An invention for providing diversity for direct sequence spread spectrum wireless communication systems is presented. The invention provides a receiver technique in which M antennas are utilized at the receiver. Distinct weighting signals are applied to information signals received at each of the M antennas, with the weighing signals being, for example, distinct changes in either phase or amplitude. Applying weighing signals to each of the information signals received at the M receiver antennas results in constructive addition of derived signal vectors at predetermined intervals, which eliminates deep fading at the receiver. Each different time varying weighting signal is determined independently of the corresponding information signal and the combined received input signal.

Abstract: A control system for the radio coverage of a cellular digital mobile communication system by a process for the lighting of radio cells, in which the mobile station (MS) is supplied with the same signal from several base stations (BS) from the edge of the cell in the mutual broadcasting system via directional aerials. One cell controller (CC) is provided for the compound optimization of the cell parameters which contains the new functions for signal processing and the control of the radio devices determined by the radio cell lighting process used.

Abstract: An error rate measurement apparatus for a mobile radio communications system, which quickly and accurately measures the error rate of received signals on a real-time basis with simple hardware. The apparatus is equipped with a plurality of receivers for receiving signals from a single transmission source with antennas spaced apart from each other. A bit comparator compares the received signals bit by bit and sends an error detection pulse signal to an error rate calculator if it has detected a bit error. The error rate calculator counts the number of error detection pulse signals sent from the bit comparator for a predetermined period. The error rate calculator then divides this pulse count by the number of incoming bits received during the predetermined period, and further divides the quotient by the number of reception signals that are compared by the bit comparator, thereby obtaining the error rate of the reception signal.

Abstract: The present invention is directed to a radio communications apparatus with combining diversity in which received radio signals are weighted appropriately to reduce an error in demodulation and improve in communication quality. In the signal combining diversity radio communications apparatus, the digital reception signals of an intermediate frequency, output from the reception circuit, are demodulated by demodulation circuits into digital demodulation signals of the baseband. The digital demodulation signals are input to the multiplication circuits. The multiplication circuits multiply the digital demodulation signals by the weight coefficients, which are generated by weight coefficient generation circuits and corresponding to the digital demodulation signals, based on C/N ratio detection signals, in order to weight the digital demodulation signals. The weighted demodulation signals are added together by a digital addition circuit.

Abstract: An amplifier circuit has an amplifying transistor which is switched on and off by a switching transistor under control of a control signal selectively applied to the switching transistor. In this way a selection is made whether or not to amplify an input signal on an antenna. The switching transistor forms part of the biasing circuit for the amplifying transistor such that when the switching transistor is on the amplifying transistor is biased off. A PIN diode and series resistor are together connected in shunt across the switching transistor such that the bias voltage which causes the amplifying transistor to be off causes the PIN diode to be forward biased thereby causing the antenna to be terminated with the resistor the value of which may be chosen to be 50 ohms.

Abstract: A diversity combiner includes a plurality of branch receiving sections each receiving a QPSK modulation signal and a vector combiner. Each of the branch receiving sections includes a level detector which detects a signal level from the QPSK modulation signal, a phase difference detector which detects a phase difference from the QPSK modulation signal in each bit interval, and a data transformer which transforms polar data consisting of the signal level and the phase difference into rectangular data consisting of two rectangular coordinate values. The rectangular data obtained by the each branch receiving sections is combined by the vector combiner to produce combined rectangular data which is in turn transformed to combined polar data.

Abstract: An antenna configuration increases the sensitivity of a base station by providing a plurality of antennas each of which cover a disjunct or partially disjunct area of a larger cell. A receiver for each antenna receives signals transmitted from mobile stations. Equalizers are attached to each receiver for correcting the received signals. A combiner then combines the received signals from the different antennas so as to form an estimate of the transmitted signal.

Abstract: An apparatus for performance improvement of a digital wireless receiver comprises a processing circuit for processing a plurality of received signals and providing a processed signal, wherein a plurality of weights is applied to the plurality of received signals producing a plurality of weighted received signals. The plurality of weighted received signals are combined to provide the processed signal. A weight generation circuit generates the plurality of weights wherein weights are based on a ratio of a desired signal, a noise signal and an interference signal.

Abstract: A digital signal processing system for obtaining accurate time delay of arrival (TDOA) and frequency delay of arrival (FDOA) measuremets of a signal of interest in a dense interfering signal environment is provided. A time series of cross-spectra (called a waterfall in the art) are computed from transforms applied to overlapping data sets comprising two received digital data streams, which include the signal from an emitter of interest and one or more partially overlapping interfering signals. For each cross-spectra frequency, a transform is calculated in the time direction to create a frequency difference of arrival dimension. Regions within the transformed cross-spectrum that are associated with individual emitters are then identified based on the fact that a given emitter's transformed cross-spectrum phase changes linearly with frequency near the peak FDOA for the emitter.

Abstract: The process according to the invention consists, in order to reduce the number of coefficients of the filters of the spatial part and the temporal part connected to the output of the spatial part, in jointly adapting the coefficients of the filters of each part using an adaptive algorithm according to the paths selected on the basis of a determined criterion. The coefficients are periodically recalculated at the rate of the known symbols in the learning sequences in order to minimize the estimation error apparent between a response signal (d(t)) and the receiver output signal (z(t)).

Abstract: Apparatus, and an associated method, for a multi-branch receiver. A receive signal is received at various receiver branches of the multi-branch receiver. Subsequent to selected processing stages of processing of the receive signal, determinations are made of the signal quality of the signal in the receiver branches. When determinations are made that the signal quality of the signal of a particular receiver branch is of poor quality, further processing of the signal in the branch is squelched.

Abstract: A time diversity transmission-reception system has, on transmit side, at least one delay of a predetermined delay for providing at least a pair of delayed and undelayed data symbol sequences, at least a pair of modulators for modulating the data symbol sequences into modulated intermediate frequency signals, and at least a pair of spread spectrum signal generators employing mutually different pseudo-random code sequences for code division multiplexing. On receive side, the received signals are subjected to code division demultiplexing, demodulation, and delaying to restore at least a pair of timed demodulated signals. These signals are then subjected to adaptive matched filtering, whose outputs are combined and applied to adaptive equalization to provide diversity reception signal. The present system provides a plurality of diversity branches without employing a plurality of frequencies, planes of polarization of a carrier wave or receiving antennas.

Abstract: This invention relates to radio communication systems and provides a signal combiner for a radio communications system having a number of receiving antennas. The signal combiner receives signals from all receiving antennas and provides a combination technique with performance close to optimal (maximal ratio) combiners but without the complexity. The invention provides a base station (10) arrangement which only processes the outputs from antennas (12) which contribute positively to the overall system carrier-to-noise ratio.

Abstract: The present invention provides a system for simulcasting and diversely receiving radio frequency (RF) signals. The system of the present invention comprises at least one RF transceiver and a plurality of RF units each including a transmitter for simulcasting an RF signal to a user and further including one receiver which is paired with another receiver in another one of the RF units, the pair of receivers providing for diversity reception of an RF signal from the user. The implementation of diversity reception with only one instead of two receivers in each RF unit, as taught by the present invention, reduces both signal loss and required cabling in the system.

Abstract: A method and apparatus for multichannel combining and equalization in a multichannel receiver is described. The receiver jointly performs diversity combining, equalization and synchronization. The method and apparatus of the present invention may be used to provide a reduced complexity adaptive multichannel receiver for use in a digital communication system.

Abstract: A method and system for demodulating received signals in radio communication systems. Pi/4-DQPSK modulated signals can be demodulated to provide additional quality measurements and to facilitate diversity combination or selection. For example, a carrier is modulated with digital data using Pi/4-DQPSK to convey two bits of data by changing the radio carrier phase from the value at the end of the last symbol through an angle of either .+-.45 degrees or .+-.135 degrees, these four possibilities representing the bit pairs 00, 01, 11 or 10. The transitions of the radio signal are filtered in the complex (I,Q) plane to limit the spectrum. At the receiver, the received signal is downconverted, filtered and amplified using a hard-limiting intermediate frequency (IF) amplifier. The IF amplifier also produces an approximately logarithmic indication of the signal strength before limiting. The hard-limited IF signal containing phase information is fed to a direct phase digitizer.

Abstract: A frequency selective noise reduction circuit and finds application in receiver demodulator arrangements in mobile telecommunication base stations. A receive signal is divided into two paths. One path includes a Phase Lock Loop circuit (PLL) which is employed to identify noise. The noise signal is inverted and then combined with the other signal.

Abstract: An adaptive signal processor (100) utilized with a receiving system (10) in a non-stationary environment having a receiver element (12) for receiving a composite signal comprised of a desire input signal and an interference signal. The invention includes a first mechanism (102) for modulating the composite signal to provide a plurality of modulated signals and to generate a plurality of synthetic channels (104). A second mechanism (126) is provided for calculating and applying a plurality of adaptive weight values to the modulated signals in the synthetic channels (104) to provide a plurality of time varying weighted signals. Finally, a third mechanism (128) is provided for combining the time varying weighted signals in the synthetic channels (104) to eliminate the interference signal from the composite signal. In a preferred embodiment, the composite signal is received by an antenna or hydrophone (12) and then digitized and stored in a memory (122).

Abstract: A digital broadcast transmission system comprises a plurality of spaced transmitters (6). Each transmitter (6) receives signals for transmission from a master transmitter (2), e.g. on a satellite, along with a reference frequency (F.sub.REF). The reference frequency is used to generate the transmission frequency at each spaced transmitter. At a receiver (12), conversion means can be used, to enable signals from the master transmitter (2) and from the other transmitter(s) to be received. A preferred application is digital audio broadcasting (DAB). Specifically, the present invention is useful in connection with Coded Orthogonal Frequency Division Multiplex (COFDM) modulation.

Abstract: An apparatus and method for use in receiving radio frequency (RF) signals having varied frequency bands from a n-sector base station antenna, and converting the RF signals to intermediate frequency (IF) signals for allocation to all available receiver radio channels. By employing a combiner and power splitter/divider, the IF signals from the converters in each sector of the receiver can be accessed by every receiver radio channel. Accordingly, remote communications users placing calls in high traffic sectors will have access to all available radio communications channels.

Abstract: A diversity receiver for receiving digital signals, particularly, but not exclusively, digital private mobile radio signals, comprises first and second reception branches (10,12) which frequency down convert respective input signals to the zero IF signals which are digitized and combined in a maximal ratio combiner (22) and the result is applied to a digital demodulator (23). The first and second branches are asymmetrical with the first branch (10) being fully specified and the second branch (12) being deliberately degraded relative to the first branch (10).

Abstract: In a radio receiver, a method and apparatus combine signals received by physically separated antennas. The amplitude of each received signal is limited. The amplitude limited signals are demodulated, and the demodulated signals are combined to form an output signal in which each demodulated signal constitutes a part in relation to a weight factor. The weight factor of the demodulated signal with a corresponding received signal having the lowest amplitude is given the value 1.

Abstract: In a diversity communication system, groups of receive units are provided corresponding respectively to arrays of antennas to process incoming signals which are propagated over different paths from a transmitter. In order to orient the directivity patterns of the antenna arrays toward the transmitter, multiple diversity branches are provided corresponding respectively to the groups of receive units. Each diversity branch includes multiple complex multipliers for respectively multiplying the processed incoming signals from the corresponding receive units by weight coefficients. Delays are then introduced respectively to the processed incoming signals so that the delayed signals are time-coincident with a decision signal, and the weight coefficients of the complex multipliers are derived from correlations between the delayed signals and the decision signal.