Abstract: A method and apparatus detects (516) a baud rate in a digital signal (442). An N-state counter (404) counts at a rate N times the baud rate and the digital signal is sampled (504) to detect transitions of the digital signal. N tallies (202) record how many transitions occur coincident with each of the states of the counter, and a total number of transitions detected is computed (508). M groups (204-210) of the tallies are formed (510) corresponding to contiguous sequential states of the counter, and for each group a group number is calculated (512) indicating how many transitions are recorded in the tallies of the group. Each group is defined (514) transitional if the group number exceeds a percentage (413) of the total number of transitions, and the baud rate is determined present or absent based upon the groups that are defined as transitional.

Abstract: A channel scanning communication receiver (204) operates in a system that transmits information in cycles (104) including subsequences (106). The receiver determines whether to operate in a scanning or locked mode by making (302) signal quality pass/fail decisions for subsequences transmitted in a predetermined group of cycles. A decision is made for a transmission of a subsequence, and subsequence active/inactive decisions are made (304) for the subsequences transmitted in the predetermined group of cycles, based upon the signal quality pass/fail decisions made for the subsequences. The receiver determines (306) whether the system is time-shared or continuous, based upon how many active decisions and inactive decisions are made, and selects (310, 312) the scanning or locked mode in accordance with predetermined rules for time-shared or continuous systems, according to whether the system is time-shared or continuous.

Abstract: An antenna (110), enclosed within a compact area of a radio (100), is not susceptible to electric fields generated from metallic shields (102, 104) located within the radio. The antenna consists of four sections of traces disposed onto a circuit board (108). The first section is a quarter-wave feed (202), which is coupled to a radio transceiver (118). The quarter-wave feed (202) converts a low impedance point (122) to a high impedance region (203). The second section of antenna (110) capacitively couples to the high impedance region (203). The third section is an isolator section (208) of half a wavelength for providing isolation from the shields (102, 104). The fourth section, quarter-wavelength radiator (214), is a trace electrically equivalent to a quarter of a wavelength having a high impedance and providing the radiating port of the antenna (110).

Abstract: A method and apparatus in a digital wireless communication system (100) controls an inter-cell hand-off. First and second fixed units (102) receive a common synchronization signal from a controller (104), and a first wireless link is established between the first fixed unit and a portable unit (120) on a first frequency. The first wireless link is synchronized to the common synchronization signal, and frame synchronization is obtained between the fixed unit (102) and the portable unit (120) during establishment of the first wireless link. Frame synchronization is maintained only by maintaining bit synchronization while transmitting user data on the first frequency. A second wireless link is established between the second fixed unit (102) and the portable unit (120) on the first frequency if the first frequency is usable therebetween. The second wireless link is synchronized to the common synchronization signal.

Abstract: The present invention comprises a method and apparatus for selecting one of at least two antennas (202, 204) in a communication unit (102) for use in a wireless communication system (100). A signal is received by a radio frequency receiver (208) during a receiving period from one of the at least two antennas (202, 204) currently selected by an antenna switch (206), the signal transmitted in a digital communications format comprising a plurality of valid data patterns and having an invalid data pattern that is not transmitted. The number of data patterns in the signal received that comprise the invalid data pattern is determined by an antenna diversity control circuit (222), and for a subsequent receiving period one of the at least two antennas (202, 204) is selected based upon the number of occurrences of the invalid data pattern determined.