Abstract: There is provided a mechanism for signalling interference protection comprising: transmitting, along with adjacent channel frequencies, an odd/even bit associated with odd/even channels that differentiates adjacent channel frequencies from one another, receiving transmitted an odd/even bit associated with odd/even channels that differentiates adjacent channel frequencies from one another, and responding to one(s) of interest while remaining unresponsive to other than that of interest.

Abstract: A cellular radiotelephone communication system cell site equipment is provided. The cell site equipment includes a radio frequency transmitter operating as one signal frequency source. In addition, the cell site equipment includes a first and a second signal combiner device tuned to a first and a second signal frequency, respectively. Further, the cell site equipment includes a radio frequency switching mechanism, operatively coupled to the radio frequency transmitter, the first signal combiner device, and the second signal combiner device, for coupling the radio frequency transmitter to either of the first and the second signal combiner devices. In one embodiment, each signal combiner device includes a resonant cavity for isolating a signal frequency source from other signal frequency sources and a coupling for coupling the isolated signal frequency source to a common transmitter output.

Abstract: A transimpedance circuit (201), and method therefor, frequency compensates an operational amplifier. The transimpedance circuit (201) has an input terminal (205) coupled to receive an amplified signal (205) and an ouput terminal (206) operative to produce a buffered amplified signal. The input terminal (205) of the transimpedance circuit (201) presents a resistive input impedance to the amplified signal at a frequency substantially near an open loop unity gain frequency of the operational amplifier (200). The amplified signal is buffered from a complex impedance of an input terminal (206) of an output driver (103). The present invention advantageously provides wide bandwidth and stable operation with loads having low complex impedance.

Abstract: A support assembly for supporting two poppel-type actuation switches at a housing, such as a radiotelephone handset housing. The actuation switches are positioned beneath a support body of the support assembly and maintained in a desired orientation relative to such support body by pawl arms which extend beneath the support body. Post members extend beneath the support body to abut against membranes of the respective actuation switches. The support body is affixed to the housing by way of retaining arms positioned to extend beneath the support body midway along the length thereof while permitting limited pivotal movement about rocker arms positioned at sides of the support body responsive to twisting moments applied to the support body. The twisting moments applied to the support body are transmitted to the poppel-type switches by way of the post members form the actuation forces to actuate the poppel-type switches supported thereat.

Abstract: The battery pack retention apparatus, described herein, is an injection molded part. The injection molded part includes a rear housing (200) for a radiotelephone (100), two rails (201, 203) for a battery pack (101) to slide along and six guide bars (207, 209, 211, 213, 215, 217) for retaining the battery pack (101) on the radiotelephone (100). Four of the six guide bars are the compliance-type. The compliance-type guide bars (207, 211, 213, 217) have a U-shape and are coupled to the rails. A channel (401) is cored out from the rails under the compliance-type guide bars to allow for deflection of the guide bars. Deflection is caused by the bullets (409) of the battery pack (101) when the battery pack (101) is fully inserted. The deflection(y) of the guide bars provides a calculated force upon the battery pack (101). This calculated force ensures a high quality electrical connection between the contacts of the battery pack and the contacts of the radiotelephone.

Abstract: A method of and apparatus for compensating a received signal's phase compensates for the distortion caused by the asymmetrical characteristics of a voltage limiter. This compensation allows the received signal to be sampled at the positive and negative zero-crossings reducing the requirements of a local oscillator in a radiotelephone system. First, the phase of the received signal is sampled at the positive and negative zero-crossings, forming a corresponding positive-crossing and a negative-crossing phase value for the received signal. Second, the negative-crossing and positive-crossing phase values are combined, forming a first difference signal. Third, an estimated error signal is formed using the first difference signal. Fourth, the estimated error signal is combined with the positive or negative zero-crossing phase signals, substantially eliminating the asymmetrical distortion.

Abstract: The present patent application discusses a frequency translation apparatus for altering the effective frequency of the phase information of an input signal (115). The input signal (115) has a first phase (.theta.(t)) and a first frequency (f.sub.i). The phase of the input signal is extracted and digitized at a second frequency (f.sub.o), forming a second N-bit digital phase signal (.theta.'(t))(311). The frequency translation apparatus generates a third digital phase signal (319) which approximates the difference between .theta.(t) and .theta.'(t). Then, the frequency translation apparatus combines the second digital phase signal and the third digital phase signal, forming a fourth digital phase signal (307) substantially approximating the first phase signal.

Abstract: A phase combining method and apparatus for use in a diversity reception radiotelephone is described. The phase combining method and apparatus is a hybrid diversity technique which combines elements of maximal ratio combining (MRC) and level comparison selection diversity, which results in a simple and effective implementation of a diversity receiver with superior performance. The diversity receiver demodulates the received signals, extracts the phase, forming two phase signals. Then, the two phase signals are combined to form a third phase signal. One of the three phase signals is selected to be used for interpretation of a symbol in the Quadrature Phase Shift Keying (QPSK) constellation. The selection process is based on the received signal strength of the received signals.

Abstract: A radio transceiver (119) including a transmitter (111), a receiver (107), and a controller (113). The controller (113) creates a fixed period reference signal (201) and a second reference signal (203) which has a variable delay in time from the fixed period reference signal (201). In addition the controller (113) creates a plurality of control signals used to control parts of the transceiver (119) and which are time dependant upon the second reference signal 203). Therefore, the adjusting of the variable delay of the second signal subsequently adjusts the plurality of control signals.

Abstract: A power amplifier controller for detecting saturation of the power amplifier (203) and corrects the automatic output control voltage (231) to avoid any further saturation. A detector (211) detects the power of the radio frequency (RF) output signal (211) and generates a signal (229) correlated to the detected power. Comparator (217) compares changes in that signal (229) to changes in the voltage of the AOC signal (231). The comparator (217) generates a signal (233) correlated to saturation of the power amplifier (203) for a DSP (223). The DSP (223) checks the status of this signal (233). Upon detecting saturation, an algorithm contained within the DSP methodically reduces the voltage of the AOC signal (231) until there is a change in the power of the RF output signal (211).

Abstract: There is provided a method of digital Automatic Gain Control (AGC) in a receiver having limited dynamic range, particularly for discontinuous signals. The method comprises detecting the level of a received and AGC'd discontinuous signal, comparing the level of the AGC'd signal relative to the dynamic range of the receiver, and adjusting the AGC to establish a desired relationship between the AGC'd signal and the dynamic range limitation. There is also provided a method of handoff in a TDMA cellular-type transmission system utilizing this method of AGControl.