A frequency synthesizer with at least two main Phase Locked Loops (PLLs) and a signal combiner, where each PLL's input is driven by a reference source of frequency F.sub.refj, and each PLL has programmable dividers in both its input path (M and P) and its feedback path (N and Q). The synthesizer utilizes a method to produce an output frequency F.sub.out that is a close approximation to a requested frequency F.sub.req. The method includes making a series of rational fraction approximations .sup.X i/Y.sub.i to the ratio .sup.F req/F.sub.refj, factoring the resulting Y.sub.i 's into several factors M.sub.i and P.sub.i, picking a pair X.sub.k, Y.sub.k that is a good approximation, but where neither M.sub.k nor P.sub.k is too large for the dividers, and then using diophantine calculation methods and a further equation relating to the way the PLL's signals are combined, to calculate N.sub.k and Q.sub.k. The integers M.sub.k, N.sub.k, P.sub.k, and Q.sub.k are then used to program the four dividers. Several forms of the invention further use a controlled reference source, and by varying F.sub.refj, allow more than one approximation to be made, and the error for each to be determined. After several such calculations, a low error one is chosen, and its M.sub.i, N.sub.i, P.sub.i and Q.sub.i values used. The invention works with synthesizers where the PLL's signals are combined to produce F.sub.out, and with synthesizers where the combined signal is used as a feedback signal for the PLL's.
A frequency synthesizer provides first and second frequency output signals based on first and second control signals, respectively. The first control signal determines the frequency of the first output signal produced by a main frequency synthesizer. The second control signal determines the frequency of a variable offset frequency signal produced by a programmable offset frequency synthesizer. A mixer combines this variable offset frequency signal with the first output signal to produce the second output signal. As such, the second output signal has a programmable variable offset frequency relationship with first output signal. First and second control signals are independently controllable. A mobile terminal may advantageously use the frequency synthesizer to generate a receiver injection signal and a transmitter carrier generation signal having a variable frequency offset relationship. Such capability permits the mobile terminal to operate within a wireless communications system employing statistical voice multiplexing techniques wherein dynamic communication channel reassignments require the mobile terminal to independently adjust its receive and transmit frequencies.
A synthesizer (100) is used for generating a plurality of synthesized clock signals (128, 156). The synthesizer includes a clock source (102) for generating a common frequency reference signal (103), and a clock generator (104) coupled to the common frequency reference signal for generating a plurality of generated clock signals (106, 108), wherein each of the plurality of generated clock signals is offset from each other by a predetermined phase offset (189, 192). In addition, the synthesizer includes a plurality of PLLs (Phase Locked Loops) (166-168) for generating a selected one of the plurality of synthesized clock signals, wherein each of the plurality of PLLs is coupled to, and operates from, a corresponding one of the plurality of generated clock signals, and wherein the predetermined phase offset between each of the plurality of generated clock signals is known to suppress noise between the plurality of PLLs operating therefrom.
A method of allocating resources includes scheduling jobs from among a plurality of resources of a work-producing system. The work producing system is a pharmacy. The method includes the steps of sorting, in a predetermined order, available resources to be utilized in the pharmacy by a last task assignment, a number of tasks performable, rate per task, and/or cost per hour, and determining one or more queues responsive to the sorting. The method also includes the step of normalizing the queue by dividing a current task queue by an average rate of the available resources for each task in the current task queue. The method also includes the step of assigning the available resources to one or more tasks with a predetermined normalized queue, subject to at least one task constraint.
