Abstract: A multicast communication method in a CDMA mobile communication system which is capable of reducing a transmission power in a base station system, and is capable of performing an efficient multicast operation for a large number of mobile subscribers is provided. The starting of information distribution by a multicast operation and identification information indicating a content of the information thereof are notified through a broadcast channel to a mobile subscriber. Further, through the broadcast channel, information such as a spread code or the like to be used at this time, which is necessary for actual reception of communication data, is notified. Then, in the mobile subscriber, a surround environment of the mobile subscriber is checked to determine the possibility of simultaneous receiving from a plurality of other base station systems. If possible, similar notified information is also received from other base station systems.

Abstract: Dynamic allocation of communication resources in a wireless communication system employing simulcast transmission. When a simulcast station of a simulcast channel at a remote site becomes unavailable, a simulcast site controller determines if there is an unused simulcast station at the remote site. If there is an unused simulcast station, the simulcast site controller assigns the unused simulcast station to the simulcast channel thereby allowing the simulcast channel to continue to function. In an alternate embodiment, simulcast stations at a plurality of remote sites are dynamically assigned to simulcast channels as they become available.

Abstract: Spread Aloha Multiple Access (SAMA) or other multiple access hubs provide feedback to each RTU on the frequency error in its transmission, so that each RTU can change its frequency output to the correct transmission frequency. At any time, and especially when a RTU has not transmitted for a time or is not transmitting, or during transmission, the hub requests that an RTU broadcast a pure tone of frequency. That pure tone produces a beat with the hub's detector. The hub filters the beat frequency and passes it to a comparator that produces a signal waveform. The period of the waveform is measured by the hub. The hub calculates the error in the RTU's carrier and sends a correction value for the RTU to use when transmitting. The hub measures slow drift in the carrier during continued transmission from a RTU and provides corrections to the RTU on the fly.

Abstract: The conventional combination cannot realize an efficient road traffic system as a whole. A transmission system has a plurality of modules installed at different positions along a predetermined road. Each of the plurality of the modules includes a receiving section for receiving an input signal and a transmission section for transmitting an output signal on the basis of the input signal according to a predetermined radio scheme. Each of the plurality of the modules receives and transmits a signal, whereby the whole or part of the information contained in the signal is transmitted along the whole or part of the predetermined road. This transmission system can construct an efficient integrated road traffic system as a whole.

Abstract: To form a wireless network, a network invitation signal is broadcast to potential members of the wireless network that are within a range of the wireless network. Upon a potential member of the wireless network responding affirmatively to join the wireless network, identification information is obtained from the potential member. The potential member is then included within the wireless network.

Abstract: The communication system executes one-to-multi peer communications between a master station (A) and many salve stations (B1, B2) by using outgoing and incoming communication media (7, 4). The master station (A) includes a data transmission processor 1, a data reception processor 2, a receiving circuit 3, the incoming communication medium 4, a multiplexer 5, a transmission circuit 6, the outgoing communication medium 7, a delay measuring unit 8, a transmission timing calculator 9, a transmission permission signal generator 10, and a system controller 11. Communications are carried out with the slave stations (B1, B2) by using the outgoing communication medium 7, and delays (d1, d2) until the master station (A) are respectively measured. A transmission interval of signals for giving transmission permission to the slave stations is obtained. The signals for transmission permission are transmitted to the slave stations (B1, B2) based on the transmission interval.

Abstract: In a cellular phone having a memory with a data base for storing a time conversion table regarding time of one place in the world belonging to a first telephone system and corresponding time of the other place in the world belonging to a second telephone system different from the first one, a method for automatically adjusting a time difference between the cellular phone and a connected base station during an international roaming comprises the steps of when a CPU of the cellular phone determines that an associated telephone system is different from that of the connected base station, the telephone system accessing the data base and looking up the conversion table for retrieving a corresponding time of the connected base station with respect to the cellular phone; and showing the corresponding time as a local time on a display of the cellular phone.

Abstract: The present invention relates to a method and network element for forwarding a multicast message received from an external packet data network (PDN) to subscribers (MS) of a packet radio network, wherein a subscriber-specific information defining multicast messages to be received by the subscribers is stored in a network element (GGSN) of the packet radio network. Based on this subscriber-specific information, a point to point connection is established between the multicast content provider of the multicast message and a subscriber having joined the corresponding multicast group. The subscriber may request a list of available multicast groups from the network element and may inform the network element of the multicast messages he wants to listen to by using a point to point context activation. Thus, the network element which may be a gateway GPRS support node plays an arbitrator role for multicast messages. Thereby, only minor changes of standard network elements are required.

Abstract: A method for polling a plurality of wireless modems from a base station in which, when a first modem is about to be polled, data that is ready to sent to a second modem is included in the poll sent to the first modem. The poll includes an indication that the data is intended for the second modem.

Abstract: An apparatus for synchronizing the system clocks of wireless devices in a digital communications system is presented. A digital phase-locked loop is employed. The phase-locked loop may include a counter which is incremented by a local device system clock and latched by a frame synchronization marker received from a remote device, whereby the counter output comprises a feed forward signal. The phase-locked loop may alternatively include a counter that reflects the level of data stored in receive and/or transmit FIFO buffers. The loop output signal controls the frequency of the system clock oscillator.

Abstract: The synchronization system uses a TDMA or AMPS air interface to provide timing synchronization between previously unsynchronized base stations. The synchronization of base stations is critical between when determining the geographical position of a mobile because the geographical position is determined using a time difference of arrival method. In order to synchronize a remote base station with a serving base station, the remote base station receives a signal from the serving base station and measuring the receiving time of the signal at the remote base station in relation to the clock of the remote base station. The synchronization system determines the transmission time of the signal based on the reception time of the signal and the distance between the base stations, in relation to the clock signal of the second station, and synchronizes the clock of the remote base station to the clock of the serving base station based on the offset in the clock cycles at the time the signal was transmitted.

Abstract: A communication system and a communication method arranged to obtain a diversity effect in mobile communication, to reduce the influence of multipath interference, fading or the like, to perform comparatively simple information communication such as message communication with improved reliability, and to achieve effective utilization of frequencies. A plurality of base stations having receivers are provided around an urban area within base station zones. The base stations repeatedly transmit the same message data. Receiving repeaters are provided in the urban area and small or medium suburban zones. Each receiving repeater relays a signal from a small mobile terminal via an Internet network if the output level of the mobile terminal is so low that direct transmission to one of the base stations is impossible. A 25 kHz frequency band is divided into four narrower bands of 6.25 kHz in one of the embodiments.

Abstract: An uncoordinated frequency hopping cellular system includes a mobile unit and a number of base stations. The mobile unit determines information pertaining to a set of base stations that are within a geographical region defined by a location of the mobile unit, and supplies, to at least one of the base stations in the set, the information pertaining to at least one other base station in the set. The information may include address information corresponding to the set of base stations, and may include clock offset information representing a difference between a clock value associated with said at least one of the base stations and a clock value associated with at least one of the other base stations in the set. As different mobile units supply information to the base station, the base station accumulates information about other base stations in the system. The base station supplies this accumulated information to mobile units, so that they may readily have information (e.g.

Abstract: A master-slave distributed communications network comprises a master node (10), a plurality of slave nodes (12 to 22), and links (VL) operatively interconnecting the slave nodes and the master node in accordance with a routing plan. Each slave node has means for storing an address of the next node in the routing plan for a message to be routed on an uplink to the master node and when sending a data packet to the master node it appends the prestored address and forwards the data packet to the next node. If the next node is not the master node, it, in turn, adds the prestored address of the next following slave node to the data packet thus lengthening the data packet and re-transmits it, and so on until the data packet reaches the master node.

Abstract: A simultaneous paging signal sending system includes at least one mobile unit, a plurality of base stations for performing communication with the mobile unit, and a base station control apparatus for controlling the base stations. The base station control apparatus includes a BAI→output port correspondence table, and a signal copying/distributing section. In the BAI→output port correspondence table, a plurality of simultaneous paging areas, in which simultaneous broadcasting is performed to the mobile unit, are grouped into one simultaneous broadcast area, and information about each base station in the simultaneous broadcast area is stored to be paired with a broadcast area identifier allocated to each simultaneous broadcast area.

Abstract: A synchronization signal used to synchronize base stations in a mobile radio telecommunication system having a first sequence followed by a second sequence, the first and second sequences being polyphase complementary sequences configured such that when the synchronization signal is correlated with a replica of the first sequence and a replica of the second sequence, and the correlation results are added exemplary synchronization results are obtained.

Abstract: A fault point location system comprising substations 1 to send information of transmission and distribution lines, and the master station 2 to locate fault points under the information. Substation 1 detects a surge detection time and the surge current polarity. Master 2 identifies a no-branch fault section under the polarity, and identifies the fault point under a difference among detection times of substations 1 at both ends of the section, and the section length.

Abstract: Disclosed is a mobile communication system including a network constituted of at least one switching center and a plurality of base stations, and a mobile station which communicates with the base stations simultaneously. The system permits varying transmission delay between the switching center and the base stations according to the type of services available to the mobile station. The object of the present invention is to propose a communication which permits varying transmission delay according to the type of service currently employed, and to promptly recover a synchronization state even if an out-of-sync state happens. To attain the object, a memory means (mobile switching center processor 32) stores transmission delay characteristics corresponding to services which are available to the mobile station.

Abstract: A dynamic service application is stored and executed on a mobile or wireless communication device (e.g., a cellular telephone) to enable it to be programmed without specialized hardware, software, and other proprietary information. For example, dynamic service application programs or scripts may be entered directly by a user or may be received as a wireless or radiated digital message transmission. The dynamic service application executes the dynamic service application script, which is of a format to accommodate wireless or radiated transmission and storage on the device. The dynamic service application script may be written directly by a user on a computer or a mobile communication device or may be written with the aid of scripting “wizard” software that runs on a computer and guides the writing of script without the user having to work directly with the dynamic service application script.

Abstract: Methods and apparatus for providing broadcast overhead information interleaved with a broadcast session in a transmission on a broadcast channel of a wireless communication system. In one embodiment, the information identifies parameters and a protocol stack for processing broadcast content. In one embodiment, the information is stored at the receiver to provide quick updating when a user changes to an alternate broadcast channel.

Abstract: There is disclosed, for use in a first radio frequency (RF) modem shelf associated with a first one of a plurality of base stations in a fixed wireless access network, a timing distribution apparatus for synchronizing the operations of a plurality of RF modems in the first RF modem shelf.

Abstract: A computer implemented method and apparatus that schedules broadcast short message service (BSMS) messages in a manner that reduces the adverse impact on voice quality and system capacity, attributable to the transmission of the BSMS messages, in a wireless telecommunications system. The method and apparatus utilize a quality of service (QoS) based broadcast message scheduler to negotiate and schedule the transmission times of BSMS messages to the individual users in the system. The quality of service (QoS) based broadcast message scheduler also allows a user to tradeoff voice quality for broadcast capacity.

Abstract: An apparatus and method for expanding a service area of a code division multiple access (CDMA) system restricted in terms of timing. The service area of a CDMA mobile communication system, which is defined by a radius longer than a radius of a communication supported area, namely, a cell, restricted in terms of timing due to the hardware of a base station modem ASIC equipped in the system, is radially divided into a plurality of radial zones by a constant distance not longer than a maximum possible cell radius allowed by the base station modem ASIC. In accordance with the present invention, signal processing units are used which are configured in such a fashion that one of them covers the entire zone of the service area in regard to forward links from an associated base station to mobile stations in different zones of the service area while covering only the zone nearest to the base station in regard to reverse links from the mobile stations to the base station.

Abstract: An efficient method for providing both dedicated and simulcast services over a common wireless infrastructure is described. The services can be available to a single terminal as well as to a multiplicity of terminals simultaneously. The method uses time division multiplexing and orthogonal frequency division multiple access for simulcasting information and transmitting dedicated message information from a plurality of base stations forming a cellular pattern over the same wireless frequency channel. The method comprises the steps of constructing frames for transmission by the plurality of base stations comprising control information, simulcast information and dedicated message information within predetermined time slots of the frames and allocating the simulcast information and the dedicated message information to time slots of the same frame predetermined by the control information of the frame. The underlying modulation technology used is OFDM and thereby the channel delay-dispersion is minimized.

Abstract: A communication system and a communication method arranged to obtain a diversity effect in mobile communication, to reduce the influence of multipath interference, fading or the like, to perform comparatively simple information communication such as message communication with improved reliability, and to achieve effective utilization of frequencies. A plurality of base stations having receivers are provided around an urban area within base station zones. The base stations repeatedly transmit the same message data. Receiving repeaters are provided in the urban area and small or medium suburban zones. Each receiving repeater relays a signal from a small mobile terminal via an Internet network if the output level of the mobile terminal is so low that direct transmission to one of the base stations is impossible. A 25 kHz frequency band is divided into four narrower bands of 6.25 kHz in one of the embodiments.

Abstract: A data providing system utilizes the resources of a digital broadcast and a network efficiently so as to provide data for a great number of users at high efficiency. The system includes a server station for communicating with terminal devices individually via the network, and a host station for transmitting the same data to all the terminal devices all at once in real time by the digital broadcast. Individual data and light-load data are handled by the server station, and the information such as load data, which should be shared by the terminal devices, are handled by the host station.

Abstract: A cellular network includes a receiver configured to receive inbound information from a mobile station. A correlator is coupled to the receiver and configured to correlate the inbound information against expected information to generate a correlator signal. An interpolator is coupled to the correlator and configured to interpolate the correlator signal to generate an interpolator signal. A memory is coupled to the interpolator and configured to store the interpolator signal. A processor is coupled to the memory and configured to process the interpolator signal to determine a position of the mobile station. Additional embodiments track the position of the mobile station based on cellular hand off and mobile station position over time. The cellular network can transfer the mobile station from the microcellular network to the macrocellular network if the mobile station is moving rapidly.

Abstract: The present invention relates to a method and network element for forwarding a multicast message received from an external packet data network (PDN) to subscribers (MS) of a packet radio network, wherein a subscriber-specific information defining multicast messages to be received by the subscribers is stored in a network element (GGSN) of the packet radio network. Based on this subscriber-specific information, a point to point connection is established between the multicast content provider of the multicast message and a subscriber having joined the corresponding multicast group. The subscriber may request a list of available multicast groups from the network element and may inform the network element of the multicast messages he wants to listen to by using a point to point context activation. Thus, the network element which may be a gateway GPRS support node plays an arbitrator role for multicast messages. Thereby, only minor changes of standard network elements are required.

Abstract: A system is provided for increasing the number of users capable of communicating over a wireless network to permit multiple users to transmit information simultaneously on the same channel or frequency in which a Viterbi decoder-based signal separation system is used to pull apart or uncorrupt the otherwise interfering signals on the channel. In one embodiment, two users are assigned to the same channel, with a joint parameter estimation pre-processor being utilized to provide an estimation of the power, time and frequency offsets and phase of the incoming signals. The joint parameters estimated by the parameter estimation unit are applied to a signal separator which recovers and pulls apart the two signals.

Abstract: A device for ensuring that the amplitude of signals fall within a predetermined range, said device comprising input means for receiving a plurality of input signals at substantially the same time, a first path for increasing the amplitude of any of the input signals having an amplitude below a first threshold, a second path for decreasing the amplitude of any of the input signals having an amplitude which exceeds a second threshold and combining the outputs of the first and second paths to provide a plurality of signals having amplitudes between said first and second thresholds.

Abstract: Interference effects between television transmitters for amplitude modulated or digital video and operating on a common allocated channel or frequency is avoided while discrimination is improved by synchronizing carrier signals for a plurality of transmitters. Booster transmitters for correcting coverage anomalies can operate of the same channel or frequency rather than requiring a different channel or frequency presently required in translators; making all allocable channels available for diverse broadcast programming. Discrimination between transmitters operating on the same channel or frequency but with potentially differing programming can be achieved with directional antennas. Synchronization of carrier signals is achieved by frequency multiplication of a tone relayed over a satellite transmission channel by an integral power of two using one or more serially connected full-wave rectifier stages and tuned filters.

Abstract: Interference effects between television transmitters for amplitude modulated or digital video and operating on a common allocated channel or frequency is avoided while discrimination is improved by synchronizing carrier signals for a plurality of transmitters. Booster transmitters for correcting coverage anomalies can operate of the same channel or frequency rather than requiring a different channel or frequency presently required in translators; making all allocable channels available for diverse broadcast programming. Discrimination between transmitters operating on the same channel or frequency but with potentially differing programming can be achieved with directional antennas. Synchronization of carrier signals is achieved by frequency multiplication of a tone relayed over a microwave transmission channel by an integral power of two using one or more serially connected full-wave rectifier stages and tuned filters.

Abstract: A retransmission control method in a multicast service providing system in which an information delivery apparatus delivers multicast information to radio terminals within a service area of the information delivery apparatus, includes two steps. The first step determines at least one radio terminal permitted to be placed in retransmission control. The second step delivers, when a request for retransmission about the multicast information sent by the above-mentioned at least one radio terminal is received by the information delivery apparatus, the multicast information to the radio terminals within the service area.

Abstract: In a transmission power control method of the present invention, a value of a received signal quality parameter of a received multicast signal is measured. A parameter signal, indicating the received signal quality parameter value, is transmitted from a plurality of mobile stations to a base station through a radio link. The parameter signals from the mobile stations are received at the base station through the radio link. A power control value of each of the mobile stations is determined based on the received signal quality parameter values of the received parameter signals. The transmission power of the multicast signal, sent to each of the mobile stations, is controlled based on the determined power control value.

Abstract: A control unit 12 executes a waiting operation by monitoring broadcast data received by a radio unit 11 and reception levels of these data at all times. When the received data being received by the radio unit 11 are found to be coincident with registered data read out from a storing unit 13, the control unit 12 causes an operating unit 14 to display a message of a content that a presence position is recognized on the display screen of a display unit 15, or it causes generation of an alarm tone from a loudspeaker 16, thus notifying the presence position recognition to the user. Afterwards, the control unit 12 sets functions of various items, such as call arrival, call arrival tone level, out-of-home dealing function ON/OFF, preset in the storing unit 13.

Abstract: In a cordless (e.g. DECT) or cellular radio telecommunication system (1), comprising a plurality of radio access units (3) operatively connecting to a central interface unit (2), transmission time delays at transmission paths (11, 12, 13) between the central interface unit (2) and the radio access units (3) are established from time differences measured between the transmission and reception of radio signals by adjacent radio access units (3). Synchronous operation at the air interface (9) is obtained by compensation of the time delays at the transmission paths (11, 12, 13).

Abstract: A communication system (105) utilizes the global positioning system (GPS) to maintain a high degree of accuracy of synchronization of base-stations (115-116). When the GPS signal (106, 107, or 108) is absent, the communication system (105) employs an alternate signal (110-113), such as a WWVB, LORAN-C, and MSF signal, to provide redundant synchronization of the base-stations (115-116). To achieve the degree of synchronization accuracy provided by the GPS signal (106-108), the communication system (105) characterizes the alternate signal (110-113) by utilizing the GPS signal (106-108) when the GPS signal (106-108) is present. When the GPS signal (106-108) is absent, the characterized alternate signal is then employed such that synchronization of the base-stations (115-116) is transparent to the base-stations (115, 116).

Abstract: A method and system for reducing the effects of atmospheric ducting on wireless transmissions, wherein a wireless communication system is comprised of a plurality of base stations having antennas, each base station having a beacon signal transmitter and a beacon signal receiver. Each beacon signal transmitter is configured to transmit a wireless beacon signal to be received by the beacon signal receiver at other, preferably every other, base stations. For each wireless beacon signal, a time delay and a propagation loss is measured. Each measured time delay and propagation loss is compared to an expected time delay and an expected propagation loss corresponding to the wireless beacon signal. The results of the comparison are processed so as to determine a location of atmospheric ducts in the region serviced by the wireless system.

Abstract: A plurality of transmitting and receiving stations are provided at randomly distributed locations within a telecommunication network, and switching circuitry is provided within the stations themselves for routing of calls between stations in the network utilizing other stations in the network for relaying of such calls where necessary. To this end each station incorporates a call routing control unit acting to select a further station to which a call from a source to a destination is to be transmitted for the purpose of relaying the call. The call routing control unit transmits an interrogation signal to be received by other stations in the network within range of the transmitting station, and the call routing control unit of each of the other stations transmits an acknowledgment signal when the station is available for relaying a call in response to the interrogation signal received from the station.

Abstract: A telecommunications system and method is disclosed for deliberately producing synchronous timing jitters in order to dynamically shift the delay spread within the overlap zone in a simulcast system. At a synchronous periodic rate, the timing differential between transmission of the signal from the control point to each of the transmitters can be continuously adjusted to continuously change the relative timing between multiple received signals in the overlap zone. Alternatively, the timing adjustments can be performed only upon reception of a retransmission request. In either case, the timing adjustments are performed so as to not be noticed by the mobile subscriber.

Abstract: A simultaneous broadcasting system, a transmitter, and a receiver therefor use a first frequency bandwidth for a wide area broadcasting and a second frequency bandwidth for a local area broadcasting obtained by dividing a frequency bandwidth of one broadcasting channel. In the simultaneous broadcasting system, a same program for the wide area broadcasting is transmitted based on an OFDM modulation method by using the first frequency bandwidth and a different program for each local area station is transmitted by using a different spreading code allocated for each local are station based on a SS modulation method.

Abstract: A system and method is provided for determining position of a mobile transmitter, such as a cellular telephone. The transmitter transmits a first signal at a first frequency (such as a RACH signal) to first and second receiving stations. The receiving sites are located at known locations. The transmitter then transmits a second signal at a second frequency (such a traffic signal) to the first and second receiving stations. The phases of the first and second signals at the first and second receiving sites are measured. Using the measured phases and the first and second frequency values, a range difference is calculated. This range difference defines a first hyperbola having the first and second receiving stations as foci on which the transmitter is located. By repeating the procedure with a different pair of receiving sites, a second hyperbola can be determined. The intersection of the first and second hyperbolas define the position of the transmitter.

Abstract: A circuit and method which provides the simultaneous transmission of page data in a paging system by delaying a reference clock signal from a global positioning system.

Abstract: In a digital mobile telecommunications station having a high frequency timebase circuit which can by synchronized with a base station timebase, the high frequency timebase circuit is shut down for a predetermined period for power saving purposes. Following completion of the shut down period, the timebase circuit is re-synchronized. A first counter counts cycles of a relatively low frequency clock while a second counter counts cycles of a high frequency clock forming part of the timebase circuit. A first storage stores the count in the second counter at a first specified point in timebase cycle during shutdown while a second storage stores the count in the second counter at a second specified point in a timebase cycle following completion of the shut down.

Abstract: This disclosure relates to a communications network including a base station and two or more distributed cells which are remote from the base station. The cells are coupled to the base station by transmission mediums which may, for example, be cable, fiber, and/or air. Between the base station and each cell, there is a time delay or transmission time, between the time when a communication that is received at one of the two is transmitted to and is received by the other of the two. The time delays of the two cells are unique or distinct one from the other. The network includes a time responsive system which is responsive to the time delay for a communication between the base station and one of the cells. Since the time delays are distinctive, the time responsive system identifies the cell associated with the communication. The time delays of the cells may be inherent in the circuitry and transmission mediums between the base station and the cells.

Abstract: A system and method are disclosed for avoiding nulls in a composite radiation pattern synthesized from a plurality of antenna beams. The disclosed invention teaches the use of delays in the signal paths associated with ones of the antenna beams utilized to synthesize the desired radiation pattern in order to avoid destructive combining of the signals. In a preferred embodiment delays are introduced in each antenna beam signal having a common attribute such as a common phase center. Accordingly, a minimum number of phase differential boundaries are introduced in order that certain communications, such as CDMA, are not adversely affected.

Abstract: A selective call receiver unit (700) capable of reducing data distortion and improving simulcast reception includes a selective call receiver (20), a demodulator (30) coupled to the selective call receiver and a circuit (36 and 300) coupled to the demodulator for reducing data distortion received at a selective call receiver. The circuit includes a detector (350) for detecting a simulcast signal, a filter (351) for windowing the symbol edge area in the simulcast signal providing a windowed symbol edge area, and a clipping circuit (36) for clipping the windowed symbol edge area.

Abstract: A signal transmitting/receiving method and apparatus freed of the drawback of the conventional information multiplexing method (FDMA, TDMA or CDMA) that information multiplexing needs a bandwidth broader than the bandwidth of the original information, such that, if the bandwidth is scanty, the number of channels that can be accommodated is decreased. A signal transmission device 10 sends three different items of the transmission information, namely the transmission information items TA, TB and TC, from three transmitters 11A, 11B and 11C, by multiplexing communication via three different paths PA, PB and PC, using a transmission antenna unit 12. A signal receiving device 20 receives the three different information items TA, TB and TC, transmitted via three different paths PA, PB and PC, by receivers 22A, 22B, 22C, using a receiving antenna unit 21, for obtaining three different items of the reception information, namely the reception information items RA, RB and RC.

Abstract: A demodulator and demodulating technique is provided which automatically switches modes according to the flat-fading or multipath channel status of an incoming signal. If an incoming signal has delay spread in addition to fading a standard Maximum Likelihood Sequence Estimator (MLSE) equalization is selected as an optimum demodulation mode. If the incoming signal is only flat-fading a symbol-based demodulation mode is selected. The Maximum Likelihood Sequence Estimator (MLSE) equalizer mode is thus integrated with the symbol based mode. Channel status is first identified in order to do mode selection in the demodulator. A dual-mode receiver for demodulating both flat-fading and multipath signals in a communications system (FIG. 1) comprises a Baseband Digital Signal (DSP) Processor further comprising a Channel Identification Processor, the Channel Identification Processor computing a Maximum Likelihood Sequence Estimate x=(x.sub.0 x.sub.1).sup.

Abstract: At least two subsets (204, 208) of simulcast transmitters are defined (802) that produce differing simulcast distortion characteristics at a receiver (210), and a message is sent (806) in a simulcast transmission from one of the at least two subsets. The message is then repeated (808, 810, 806) in a simulcast transmission from another of the at least two subsets, until all of the at least two subsets have transmitted the message.