Abstract: A method voting multiple messages begins with a communication unit (111) transmitting (301) a message. At each of a plurality of sites, the message is received (303) and decoded (305) such that a minimized metric is computed and decoded message is extracted from the message. The minimized metric is adjusted (307), producing an adjusted metric. Each of the plurality of sites transports (309) its decoded message and its adjusted metric to a comparator. The comparator receives (311) selecting the decoded message and the adjusted metric from each of the plurality of sites, compares (313) selecting the adjusted metric from each of the plurality of sites and finds an optimal adjusted metric. The decoded message associated with the optimal adjusted metric is then selected (315).

Abstract: A communications system comprising a central unit (200) and a number of remote units (300) and a downlink (10) for communication from the central unit to the remote units and an uplink (11) for communication from the remote units to the central unit. A signalling channel is provided on the downlink, a plurality of traffic channels are provided on the uplink and signalling information is transmitted on the downlink signalling channel to indicate positively which of one or more of the uplink traffic channels is to be used as a signalling channel for a random access request.

Abstract: In a system for transmitting digital information, transmitter operating parameters (503) are transmitted with other communication message information (501, 505, 507, 509, 511, 513, 515, and 517) to aid communications.

Abstract: A method of low-splatter peak-to-average reduction for a linear communication system includes the step of sampling (1201) an input signal at a first rate, yielding a plurality of input samples. When at least one (1401, 1403, and 1405) of the plurality of input samples is above a first threshold, a local maximum (1401) is determined (1207) from among the plurality of input samples. At least one value (1407 and 1409) is interpolated (1207) between the local maximum and at least one sample (1405) adjacent to the local maximum. The at least one value and the local maximum are compared (1211) to determine which has the highest magnitude. The value having the highest magnitude (1407) is compared (1213) to a second threshold. When the value having the highest magnitude (1407) is above the second threshold, an attenuating window is centered (1505) at the value having the highest magnitude and applying (1507) the attenuating window to at least some of the plurality of input samples.

Abstract: Communication units organized into user groups are divided into user groups that distinguish whether a member of the user group may or may not interrupt active calls. Communications will not be interrupted (303) by units that are not allowed to interrupt active calls. Communications are interrupted (304) only by units that are allowed to interrupt active calls.

Abstract: An apparatus for and method of testing the components of a communication system that uses an ARQ protocol is provided. A processor (117) within the communication system is designated to emulate the ARQ protocol so that the normal paths of communication through the system are tested by creating a path (405) that isolates components (103 and 105) from the remainder of the system and tests the remaining components (107 and 109) using the ARQ-emulating processor (117). The processor (117) is also used to emulate a second protocol.

Abstract: When it is desired to transmit important or secure information to one or more communication units, a message is transmitted (200) to only valid communication unit ID codes. The message requests an acknowledgment transmission from the communication unit, including the communication unit's ID code. When no acknowledgment is received for a particular ID code, the message is transmitted again after a period of time (204). When only one acknowledgment is received for a particular ID code, the important or secure information is then transmitted (206) to that particular ID code. When more than one acknowledgment is received for a particular ID code, no important or secure information is transmitted to that particular ID code, and the ID code is flagged (207) as a potential unauthorized ID code.

Abstract: Information regarding available services from a RF communication system (101) is transmitted by the RF communication system on an RF communication resource(109). The information is received by at least one communication unit (108). The at least one communication unit (108) determines, from the information, the available services. The at least one communication unit (108) displays an indication of the available services on a display (206) for a user.

Abstract: A method of transmitting messages, where transmitting a message requires a plurality of transmissions, includes communicating control information, e.g., a communication resource allocation request (106) and a communication resource assignment (110), between a controller (101) and a communication unit (104) on a control communication resource (114), such that a working communication resource (115-117) is assigned to the communication unit (104). While the communication unit (104) is engaged in a first transmission of the message on the working communication resource, the control information is communicated between the controller (101) and the communication unit (104) on the working communication resource (115-117), such that the working communication resource (115-117) is assigned to the communication unit (104) for a second transmission of the message.

Abstract: A multiple-modulation communication system includes a transmitter that modulates and transmits communication signals modulated by a first modulation technique and communication signals modulated by a second modulation technique. The first modulation technique and the second modulation technique are different. The communication system also includes a receiver capable of receiving the communication signals modulated by the first modulation technique and the communication signals modulated by the second modulation technique and demodulating the communication signals.

Abstract: Received signal strength calculations in a radio are carried out by hardware which scales the absolute value of components of the received signal in a linear fashion by using two scaling factors.

Abstract: A zero-IF transmitter (200) has a DC offset, representative of a carrier feedthrough signal. A value to correct the DC offset is successively approximated (207). A summer (201) adds the value to a desired input to reduce the DC offset.

Abstract: An identification (ID) code (204) in a memory slot (203) within a communication unit (200) is programmable only through a received RF message and a valid trigger for programming the memory slot (203). No other connection to the radio, such as a standard programming port (206), is capable of being used to program the memory slot (203). An ID code (204), such as a security ID, is programmed via an RF message. The ID code (204) is a special code known to a communication system. No request for a communication resource is granted to a communication unit (200) that does not have the ID code (204), thereby keeping unauthorized users from gaining access to the communication system.

Abstract: A method of providing a radio communication unit (120) with information regarding radio communication services. The radio communication unit transmits a request regarding availability of one or more specific radio communication services. The radio communication unit then receives information regarding availability of the specified radio communication services.

Abstract: When a portable radio (110) receives a transmission from a mobile radio (105), the portable radio (110) mutes a speaker volume of the portable radio (110) for a duration of the transmission from the mobile radio (105). In an arrangement of the mobile radio (105) and the portable radio (110) where both radios transmit and receive on a same communication resource channel and both radios are in close proximity, acoustic feedback may be avoided.

Abstract: This invention relates to a time division multiple access (TDMA) trunked radio system and it relates to a frame structure for communication between fixed, mobile and portable radios in such a system. The radio system comprises: a base station and a plurality of remote radio units for communicating over time slots of a time divided radio channel, the base station having means for transmitting a synchronization signal for defining the timing of the time slots, and each of the remote units having a power amplifier with linearization means, characterized in that the channel comprises predetermined linearization time slots (120, FIG. 2) for transmission of training signals, interspersed between other time slots and each remote radio unit comprises means for generating a training signal during a linearization time slot and linearizing its power amplifier during that time slot in advance of and independent of transmission of signals during one of said other time slots.

Abstract: A linear amplifier (103) has a negative feedback loop that has a closed loop gain and a forward path gain. The negative feedback loop is closed, such that quick changes in the closed loop gain are prevented, thereby reducing splatter. When the negative feedback loop is opened, quick changes in the closed loop gain are also prevented, thereby reducing splatter.