Abstract: An equal gain composite beamforming technique which constrains that the power of the signal output by each antenna is the same, and is equal to the total power of the transmit signal divided by the number N of transmit antennas from which the signal is to be transmitted. By reducing output power requirements for each power amplifier, the silicon area of the power amplifiers are reduced by as much as N times (where N is equal to the number of transmit antennas) relative to a non-equal gain CBF.

Abstract: Disclosed is a transmission diversity method in a mobile communication system, by which optimal transmission diversity can be provided in case that a base station of the mobile communication system uses at least one transmitting antenna. The present invention includes the step of having a transmitting side transmit signals using a plurality of antennas wherein a transmission signal of a second antenna differs from a transmission signal of a first antenna in a predetermined phase.

Abstract: An adaptive beamforming method for an antenna array is provided in which an array output is calculated based on a weight vector w, which is determined from an eigenvector corresponding to a maximum eigenvalue&lgr; of a generalized eigenvalue problem consisting of autocovariance matrixes Rxx and Ryy of received signal vectors y and x, respectively. The present invention dramatically decreases the total computation requirements by omitting complex matrix operations from the weight vector calculation, thereby making it possible to reduce the weight vector calculation time so as to form the beam pattern for the array antenna system in real time.

Abstract: A diversity receiver includes a plurality of antennas, a receiving unit for receiving radio waves via the antennas, a phase adjuster disposed for each said antenna and connected thereto for adjusting a phase angle of a radio wave received by each of the antennas to a value to increase gain of each antenna to which the phase adjuster is not connected, and a switching unit, operative in response to a control signal indicating a selected antenna having a best reception state to receive an external radio wave, for connecting the selected antenna to the receiving unit, for disconnecting the selected antenna from the phase adjuster and non-selected antennas other than the selected antenna, and for connecting the non-selected antennas to the phase adjuster associated therewith. The phase adjuster is connected in a stage subsequent to the switching unit viewed from the antennas. This configuration provides a highly efficient diversity receiver.

Abstract: A radio communication system includes a base station having a directional antenna for generating a plurality of beams. A first set of the beams is used to receive signals which are decoded at the base station. A second set of the beams is used for interrogating a cell to identify beams which should be added to the first set of beams (for example, in response to mobile terminals entering the cell). In one embodiment, the second set of beams comprises a plurality of searcher beams produced by a fixed-beam phased array antenna. In a second embodiment, the second set of beams comprises a single searcher beam which is scanned through the cell by an adaptive phased array antenna. The radio communication system can be used to communicate with indoor mobile terminals through a plurality of radio heads, and also can be used to communicate with orbiting satellites.

Abstract: Embodiments of the present invention relate generally to receivers. One embodiment relates to a digital FM receiver having multiple sensors (e.g. antennas). In one embodiment, the digital receiver includes a baseband unit having a channel processing unit. In one embodiment, the channel processing unit is capable of calculating or estimating a phase difference between the incoming signals prior to combining them. One embodiment uses phase estimation method for diversity combining the signals while another embodiment utlizes a hybrid phase lock loop method. Also, some embodiments of the present invention provide for echo-cancelling after diversity combining. An alternate embodiment of the channel processing unit utilizes a space-time unit to diversity combine and provide echo cancelling for the incoming signals.

Abstract: A wireless base station includes a determining unit, a first calculation unit and a control unit. The determining unit determines a direction in which a specified mobile station that is to be spatially-multiplexed is located. Then, the first calculating unit calculates a first parameter group, used to form a first directional pattern for each already connected mobile station that should be spatially-multiplexed with the specified mobile station. The first directional pattern is such that a null point is formed in the determined direction. After a link channel allocation has been transmitted to the specified mobile station, the control unit performs control, so that transmission is performed to each already connected mobile station by forming the corresponding first directional pattern and further by reducing transmission power uniformly in all directions.

Abstract: Embodiments of the present invention relate generally to receivers. One embodiment relates to a digital FM receiver having multiple sensors (e.g. antennas). In one embodiment, the digital receiver includes a baseband unit having a channel processing unit. In one embodiment, the channel processing unit is capable of calculating or estimating a phase difference between the incoming signals prior to combining them. One embodiment uses phase estimation method for diversity combining the signals while another embodiment utlizes a hybrid phase lock loop method. Also, some embodiments of the present invention provide for echo-cancelling after diversity combining. An alternate embodiment of the channel processing unit utilizes a space-time unit to diversity combine and provide echo cancelling for the incoming signals.

Abstract: A flat-panel repeater includes a housing having a pair of oppositely facing surfaces, at least one antenna element mounted to each of the surfaces for radiating energy in a direction opposite to that of an antenna element mounted to the other of the surfaces, and an electronic circuit mounted within the housing and operatively coupling signals between at least one antenna element on each of the oppositely facing surfaces of the module. Isolation between the antennas on opposite sides of the repeater is improved by various techniques, such as use of adaptive cancellation which removes a significant portion of the feedback signal power, therefore increasing the total system isolation by the same amount. This additional isolation can be used to achieve greater system gain, and therefore significantly extend the range of the system.

Abstract: An improved receiving phased array communication system supplies oscillating waveform signals with different phase delays to downconverting mixers in the processing channels of the receiving phased array communication system to compensate for phase difference in the received signal over the antenna elements therein. Similarly, an improved transmitting phased array communication system supplies oscillating waveform signals with different phase delays to the upconverting mixers in the processing channels of the transmitting phased array communication system to introduce phase difference in the transmit signal for transmission over the antenna elements therein. The oscillating waveform signals with different phase delays are preferably derived from a local oscillator that generates a local oscillating signal, and a delay line network having a plurality of fixed delay lines arranged in a serial manner to introduce increasing fixed phase delays in the local oscillating signal.

Abstract: A composite beamforming technique is provided wherein a first communication device has a plurality of antennas and the second communication has a plurality of antennas. When the first communication device transmits to the second communication device, the transmit signal is multiplied by a transmit weight vector for transmission by each the plurality of antennas and the transmit signals are received by the plurality of antennas at the second communication device. The second communication device determines the best receive weight vector for the its antennas, and from that vector, derives a suitable transmit weight vector for transmission on the plurality of antennas back to the first communication device. Several techniques are provided to determine the optimum transmit weight vector and receive weight vector for communication between the first and second communication devices so that there is effectively joint or composite beamforming between the communication devices.

Abstract: Polarization modulator devices can be formed to take advantage of multi-layered semiconductor structures. High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. An accommodating buffer layer comprises a layer of monocrystalline oxide spaced apart from a silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline material layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer.

Abstract: Antenna reception diversity is provided for wireless communications such that a received signal (r) can be produced by combining antenna signals (vi) with their associated fading amplitudes (&agr;i) as estimated by a linear receiver (32). Also, antenna signals (v1i) can be combined with their associated correlation values (&agr;1i) in place of estimated fading amplitudes. Further, inherent characteristics of a non-linear wireless communication receiver can be exploited such that a received signal (r2, r3) can be produced without any additional overhead that would otherwise be needed to provide estimated fading amplitudes.

Abstract: In a device and a method for correcting scanning signals of incremental position transducers, which exhibit deviations from the signal shape required by a downstream evaluation unit, the scanning signals are fed to a correction unit in response to a signal request and, to implement the correction, are linked there to correction data which were generated in consideration of active values of the scanning signals. Following each signal request, for at least one predefined time segment, the correction unit is exclusively fed scanning signals which are used for generating correction data.

Abstract: An interference protection system includes a receiving section for receiving an electromagnetic signal, a detector for detecting a jamming signal, and a control system for orienting a changeable null direction of an antenna system to reduce interference in a receiver from the jamming signal.

Abstract: An antenna for communicating with mobile devices in a land-based cellular communication system via an antenna beam having a width, azimuth angle and downtilt angle. The antenna includes: a two dimensional array of radiating elements (31-34); and a feed network (35-39) from a feed line to the radiating elements. The feed network includes: downtilt phase shifting means (35,36) for varying the phase of signals supplied to or received from the radiating elements so as to vary the downtilt angle of the antenna beam; azimuth phase shifting (38,39) means for varying the phase of signals supplied to or received from the radiating elements so as to vary the azimuth angle of the antenna beam; and beam width adjustment means (37) for varying the power or phase of signals supplied to or received from the radiating elements so as to vary the width of the antenna beam.

Abstract: A composite beamforming technique is provided wherein a first communication device has a plurality of antennas and the second communication has a plurality of antennas. When the first communication device transmits to the second communication device, the transmit signal is multiplied by a transmit weight vector for transmission by each the plurality of antennas and the transmit signals are received by the plurality of antennas at the second communication device. The second communication device determines the best receive weight vector for the its antennas, and from that vector, derives a suitable transmit weight vector for transmission on the plurality of antennas back to the first communication device. Several techniques are provided to determine the optimum transmit weight vector and receive weight vector for communication between the first and second communication devices so that there is effectively joint or composite beamforming between the communication devices.

Abstract: A surface-acoustic-wave filter has a piezoelectric substrate; and a plurality of transversal surface-acoustic-wave (SAW) filters set on the piezoelectric substrate and respectively having at least two inter-digital transducer (IDT) electrodes for transcieving surface acoustic waves, characterized in that periods for surface acoustic waves to propagate from inputs to outputs of the SAW filters differ in the SAW filters and thereby, timings of outputs from the SAW filters are different from each other.

Abstract: The adaptive receiving block 2k for the k-user generates a receiving signal by the k-th user the m-th path inherent antenna directivity pattern respectively, obtains the k-th user demodulation signal by demodulating and adding for each path simultaneously and outputs weight control error signal e′kl˜e′kM for the purpose of forming directivity pattern for each path. The weight control error synthesis circuit 3 optionally synthesizes weight control error signal e′kl˜e′kM and outputs synthesis weight control error signal e′kl˜e′km. Synthesizing weight control error signals with respect to paths whose arrival directions of multi-path of each user are close, performing a control without synthesizing weight control errors with respect to paths whose arrival directions are apart, increasing the information available for adaptive control and enhancing an adaptive control characteristic and an interference suppression ability.

Abstract: The present invention provides a method and system for estimating common amplitude and phase errors of a multiple channel wireless system. The multiple channel wireless system includes a plurality of transmission channels formed between a plurality of transmission antennas and a plurality of receiver antennas. The method includes estimating transmission channel elements between each transmission antenna and receiver antenna pair of the multiple channel wireless system. Calibration symbols are transmitted from each transmit antenna. Signals are received that correspond to the calibration symbols having traveled through the transmission channels. Received calibration symbols are estimated based upon spatial processing of the received signals and the estimated transmission channel elements. Common amplitude and phase errors are estimated for each transmit and receive antenna pair by comparing the transmitted calibration symbols with the received calibration symbols.

Abstract: A method and apparatus for processing cochannel signals received at a sensor array in a cumulant-based signal processing and separation engine to obtain a desired set of output signals or parameters. For use in a signal recovery system, the output signals are recovered and separated versions of the originally transmitted cochannel signals. An important feature that distinguishes the cumulant-based system from other signal separation and recovery systems is that it generates an estimated generalized steering vector associated with each signal source, and representative of all received coherent signal components attributable to the source. This feature enables the invention to perform well in multipath conditions, by combining all coherent multipath components from the same source. In a receiver/transmitter system, the estimated generalized steering vectors associated with each source are used to generate transmit beamformer weight vectors that permit cochannel transmission to multiple user stations.

Abstract: A method and apparatus are provided that allows initial beamforming weights to be determined before timing or delay and frequency offset are known. According to one aspect of the present invention, the invention includes receiving a burst from a terminal at a set of spatial diversity antennas, the burst including a known training sequence and storing measurements of the received burst from each spatial diversity antenna corresponding to receive times within a selected analysis window. The invention further includes determining weights for each diversity antenna for at least a portion of the training sequence of the burst before timing for the burst has been determined, applying the determined weights to the stored measurements and determining timing for the burst based on the stored measurements to which the determined weights have been applied.

Abstract: Distortion is reduced in a radiocommunications system in which a radio signal is received with a carrier frequency with a group antenna. The group antenna includes at least two receiver channels with an antenna element and components for amplifying and processing the respective signal. A first phase shift by a predetermined value is performed directly after reception of the signal in the respective channel. A second phase shift by a value is performed which corresponds to the first phase shift but in the opposite direction. In this manner, distortion which arises as a result of, for example, non-linearities in an antenna array, is reduced.

Abstract: A periodical signal is transmitted from a cellular base station. A memory circuit having a capacity of the signal for one cycle is provided. Newly received information is added to information previously accumulated in the memory circuit, and the resultant information is again accumulated in the memory circuit, thereby enabling the received information to be stored in the memory circuit having the capacity for only one cycle of the signal. Conventionally, a large amount of memory has been required to perform coherent adding for a long time period, whereas the present invention can reduce the circuit scale and the amount of memory, and also reduce the number of times of operations required for the long-period coherent adding, when a mobile station is located using a cellular communication system.

Abstract: Antenna elements 101-1˜101-2N, provided on a linear line at regular intervals to be parallel to each other, receive signals transmitted from the communicating partner, and output them to receiving beam former 103. In receiving beam former 103, phase shifters 104-1˜104-N phase-shift the received signals input from the antenna elements of an even element number by &pgr;. Combiner 105 adds up the received signals that are phase-shifted by &pgr; in phase shifters 104-1˜104-N and the signals input from the antenna elements of an odd number, and thus so forms a received beam. By this means, it is possible to realize an array antenna apparatus of a small and simple configuration that reduces the radiation of radio waves to the human body and equipment and that is influenced little by the human body and equipment.

Abstract: A radio equipment 1000 separates a signal of a specific terminal from signals from adaptive array antennas #1 to #4, based on a reception weight vector calculated by a reception weight vector calculator 20. Reception coefficient vector calculator 22 provides an impulse response of a signal propagation path of the specific terminal. A transmission coefficient vector estimator 32 predicts a propagation path at the time of transmission, from the result of estimation by the reception coefficient vector calculator 22. The transmission weight vector calculator 30 controls, based on the result of prediction by the transmission coefficient vector estimator 32, the antenna directivity at the time of transmission. Thus, degradation of error rate of the down link generated by the time difference between up/down links can be suppressed.

Abstract: A signal reception circuit includes a main antenna which receives signals in at least two predetermined reception frequency bands. A sub-antenna receives a signal in one of the reception frequency bands of the main antenna. A filter for interrupting a signal in the same frequency band as the reception frequency band of the sub-antenna is provided on a transmission line of a reception signal of the main antenna. A filter reflection signal in the same frequency band as the reception frequency band of the sub-antenna is induced in the sub-antenna, due to the antenna coupling thereof. The phase of the filter reflection signal is adjusted by a phase shifter between the main antenna and the filter, so that the induced signal of the sub-antenna is in phase with the reception signal of the sub-antenna. As a result, the level of the composed signal of the induced signal and the reception signal and is to be transmitted from the sub-antenna to a signal processing unit is greatly improved.

Abstract: A method of generating a weight vector based on the maximum signal-to-interference-plus-noise output power ratio (SINR0) criteria without an eigenvector finding technique, is provided for use in a smart antenna system. The weight vector is applied after pseudo noise (PN) dispreading rather than in front of a receiver for channel estimation and data symbol demodulation. The method includes setting an initial weight vector w(0) and a convergence parameter or an initial eigenvalue. New post-PN processing vectors y(i) and new pre-PN processing vectors x(i) are received. The weight vector w(k) at a snapshot k is then updated and optimized.

Abstract: A low profile, vehicle mounted, in-motion tracking, satellite antenna includes a pair of antenna assemblies mounted in parallel on a rotatable platform. Each antenna assembly includes two subreflectors with a plastic matching element. The outputs of the two antenna assemblies are coupled with a single phase shifter. The combined outputs are retransmitted to a receiver inside the vehicle. The satellite antenna also includes a receiver for receiving channel selection data and/or for providing two-way communication with equipment inside the vehicle. The antennae, transmitter and receiver are self-powered by a storage device which is charged by a wind driven generator. A retractable radome lowers to a lower profile when the antenna is not in use.

Abstract: A path search processing section 110 of a searcher 108 performs despreading processing for a signal that has undergone AAA reception by an MF 110a. A power addition circuit 110c adds power of a signal in which coherent addition of a despread signal has been performed, and outputs the result to a delay profile circuit 110d and also to threshold value decision circuit 111. Outputs from respective threshold value decision circuits 111 are output to a combining circuit 112. A power combination value combined by the combining circuit 112 is output to a delay profile circuit 113, and a delay profile is created based on this power combination value. A finger assignment circuit 114 finds despreading timing for AAA reception weight control from the delay profile.

Abstract: An adaptive signal processing section 107 calculates reception weights by adaptive signal processing of demodulation signals for communication terminal apparatus from a demodulation section 106; and performs multiplication processing, using the above demodulation signals and the reception weights. And, when communication is opened, the above adaptive signal processing section 107 may execute multiplication processing, using the reception weights stored in a storage section 109 at the previous communication with the above communication terminal apparatus, and the demodulation signals.

Abstract: A receiver and an associated method are disclosed for combining signals having substantially different polarizations. The receiver is used with a first antenna which receives first polarized signals and a second antenna which receives second polarized signals, the first polarized signals having a substantially different polarization than the second polarized signals. The receiver includes a phase shifter and a combiner circuit. The phase shifter adjusts the phase of the first polarized signal in response to the phase of the second polarized signal to produce a phase compensated first signal. The combiner circuit sums the second polarized signal and the phase compensated first signal to generate a combined polarization received signal. In this manner, the depolarized signals are phase-aligned with, and then combined with, the polarized signals to provide a strong received signal irrespective of any depolarization of the received signal.

Abstract: The invention relates to a method and a system for improving operation of a radio link in a wireless communication system, such as a cellular radio system, by modifying the radiation pattern of an antenna array on the downlink by means of the information obtained from the uplink. The method comprises determining the location of a receiver for transmission by means of an angular power spectrum (400), for example. Then the radiation pattern of a transmitting antenna array is shaped on the basis of the location information on the receiver by selecting a window function which provides the desired radiation pattern and by implementing the form of the window function by means of antenna element specific coefficients (502, 504). (FIG.

Abstract: A combiner for a diversity radio receiver wherein amplitude inversion of either received signal is performed, on a selection basis, in order to maximize the resultant output combined signal. The strength of each diversity signal is monitored as well as the strength of the combined output signal. A gain control engine combines the stronger signal with either the inverted or non-inverted weaker signal to maximize the combined output (resultant) signal strength. According to another embodiment the combiner may additionally perform an amplitude adjustment whereby the in-channel noise power is also monitored and the individual channel signal-to-noise ratios are used to adjust the amplifier gains. In this embodiment the individual channel signal-to-noise ratios plus the strength of the combined output signal are used to decide whether to invert the weaker signal before combining the received signals.

Abstract: A synchronization system within a dual antenna receiver employs two timing recovery loops each coupled to a different antenna input. Segment sync lock (detection of a segment sync in the data stream) by one timing recovery loop prompts selection of the timing error from the corresponding timing recovery loop for timing recovery within both loops. Both timing recovery loops are then synchronized utilizing the selected timing error. If sync lock for the selected loop is lost, the other loop is selected to provide timing error to both loops.

Abstract: Delay profiles of respective branch received signals received through a plurality of antennas are formed; peaks on each of formed delay profile signals are detected; the maximum peaks are obtained among detected peaks on the respective delay profile signals; and average delay differentials between the delay profiles are obtained by averaging a desired number of delay differentials among the maximum peaks.

Abstract: A reception circuit includes a reception section and control section. The reception section performs frequency conversion of an input signal by using a local frequency signal generated by phase comparing operation. The control section removes a passing phase error, added in the reception section, on the basis of a phase comparison signal output from the reception section. An adaptive array antenna system is also disclosed.

Abstract: A phase compensation circuit, for use with an FM reception system, includes a delay circuit and a control circuit. The delay circuit receives a composite input signal that exhibits a variable phase error and provides a plurality of selectable discrete delays. The control circuit is coupled to the delay circuit and receives a control signal whose value corresponds to the phase error associated with the composite input signal. The control circuit selects one of the plurality of selectable discrete delays responsive to the control signal, which is utilized to delay the composite input signal to provide a phase compensated composite output signal.

Abstract: A distributed antenna system for use in an in-building cellular telephone network, the system including a base transmission station (BTS), and a distributed antenna for conveying transmissions to and from the BTS, the distributed antenna including a plurality of serially-interconnected radiant segments, and at least one delay element intermediate two of the plurality of radiant segments, where the delay element is operative to introduce a delay in a transmission between the BTS and a mobile station (MS), where the BTS is operative to discern the delay in the transmission and thereby determine which of the plurality of radiant segments is closest to the MS and selectively radiate RF energy via the closest segment and prevent the radiation of RF energy via any other of the plurality of radiant segments.

Abstract: A directional antenna system includes several antenna elements, a phase shift/attenuation circuit, and a switching system. The circuit synthesizes four antenna patterns which are oriented toward the front, back, left, and right sides of a vehicle. The system switches between antenna patterns depending upon received signal strength at any particular moment.

Abstract: A repeater diversity system includes a null antenna having a given phase center and polarization for receiving a communications signal from a remote signal source, a donor antenna for transmitting a signal to a base station, and a diversity null antenna having the same phase center as the receive null antenna and a polarization orthogonal to the polarization of the main null antenna. A combining network is coupled to the main null antenna and the diversity null antenna for combining the signals therefrom and an uplink channel module is coupled with the combining network for delivering diversity combined receive signals to the donor antenna.

Abstract: The present invention describes an inexpensive as well as efficient smart antenna processor for a code division multiple access (CDMA) wireless communications system, such as a 3rd generation (3G) CDMA2000 or W-CDMA system. Separate channel estimation is not required in the present invention, in contrast to a CDMA system with a conventional smart antenna. In addition, the phase distortions due to the different radio frequency (RF) mixers can be automatically compensated in the present invention. Thus, separate phase calibration is not necessary for a smart antenna processor according to the present invention, if the reverse link demodulation is concerned. Furthermore, bit error rate (BER) performance of a CDMA system with the adaptive algorithm in the present invention can be smaller than that of a conventional algorithm, for fading and additive white Gaussian noise (AWGN) environments.

Abstract: In a helical antenna comprising a hollow cylindrical member having an inner peripheral surface and an outer peripheral surface and an antenna pattern film wound around the outer peripheral surface of the hollow cylindrical member, the helical antenna further comprises a center rod coaxial with a center axis of the hollow cylindrical member and at least three ribs disposed between the center rod and the inner peripheral surface of the hollow cylindrical member. The ribs symmetrically extends in a radial manner at equal angular intervals. The hollow cylindrical member, the center rod, and the ribs preferably may be integrally molded out of plastic. The antenna pattern film may comprise a flexible insulator film and a conductive pattern formed on the flexible insulator film. The conductive pattern has at least one antenna lead member which is wound around the outer peripheral surface of the hollow cylindrical member in a helix fashion.

Abstract: A communication station (1) for contactless communication with at least one transponder is provided with a transmission coil configuration (2) with an active, first transmission coil circuit (21) which includes a first transmission coil (36) and with a passive, second transmission coil circuit (22) which includes a second transmission coil (42), the first transmission coil (36) as well as the second transmission coil (42) being connected to a respective central conductor (38, 50) which is connected, via a third capacitor stage (41, 53), to a connection conductor (33, 48) between two series-connected capacitor stages (31, 32 and 47, 49), the two capacitor stages (31, 32 and 47, 49) constituting capacitor means (30, 43) which are connected parallel to the relevant transmission coil (36, 42).

Abstract: A space diversity antenna system provided with dither circuitry in the signal path to one of the antennas to switch a circuit element in and out of the signal path at a high rate. The circuit element can be an amplitude attenuator or a phase changer. This switching results in the substantial elimination of nulling between the two antennas.

Abstract: An adaptive antenna reception apparatus includes a reference signal level determination section, reception level detection sections, and beam formers. The reference signal level determination section determines the level of a reference signal for generating an error signal used for antenna adaptive control on the basis of a reception level of each antenna before beam forming. The reception level detection sections calculate antenna weighting factors for the respective paths on the basis of the multiplex signals received through the respective antennas and the error signal output from the reference signal level determination section. The beam formers receive the received multiplex signals and form antenna directivity beams for the respective paths in accordance with the antenna weighting factors output from the reception level detection sections.

Abstract: A diversity reception system used for a mobile radio communication system of a sector type is constructed using single-directivity transmitting-receiving antennas and a non-directivity receiving antenna, all of which are fixed to a support pole such as a steel pipe pole and a steel tower. The single-directivity transmitting-receiving antennas are fixed to a peripheral surface of the support pole and are arranged in directions corresponding to sectors respectively. The non-directivity receiving antenna is fixed to a head portion of the support pole and is arranged above the single-directivity transmitting-receiving antennas by a prescribed interval of distance, which corresponds to at least nine wavelengths of radio waves. The single-directivity transmitting-receiving antennas are connected to transceivers, each containing a diversity receiver, respectively.

Abstract: The phase of a transmitted signal is regulated in a device which is part of a system for electromagnetic signal transmission. The transmitted signal has periods when it contains information and periods when it does not contain information. The modulation position of a phase shifter which has a linear and a non-linear range is controlled. Power of the signal is amplified. Unwanted phase shifts in the signal transmitted by the device caused within the power amplifier are detected, and the information content of the signal is detected. The phase shifter is reset to a particular predetermined modulation position in the event of detection of the absence of information in the signal. The predetermined modulation position to which the phase shifter is reset is preferably situated within the linear range of the phase shifter.

Abstract: In a radio communication apparatus, delay profiles of a desired wave and delay waves thereof are estimated by plural delay profile estimation sections for each of received signals from directional antennas constituting an array antenna. Received signals from the antennas selected by a reception antenna selector on the basis of the delay profile are subjected to a temporal/spatial equalization processing by an adaptive signal processing section and a path diversity combining section, thereby obtaining a reception output. An arrival angle range of the desired wave is estimated by a DOA estimation section from the delay profile estimated by the delay profile estimation section. Based on the arrival angle range, the antenna for transmission is selected by a transmission antenna selection section, and transmission signals are sent out.

Abstract: A diversity receiver includes a plurality of antennas, a receiving unit for receiving radio waves via the antennas, a phase adjuster disposed for each said antenna and connected thereto for adjusting a phase angle of a radio wave received by each of the antennas to a value to increase gain of each antenna to which the phase adjuster is not connected, and a switching unit, operative in response to a control signal indicating a selected antenna having a best reception state to receive an external radio wave, for connecting the selected antenna to the receiving unit, for disconnecting the selected antenna from the phase adjuster and non-selected antennas other than the selected antenna, and for connecting the non-selected antennas to the phase adjuster associated therewith. The phase adjuster is connected in a stage subsequent to the switching unit viewed from the antennas. This configuration provides a highly efficient diversity receiver.