Digital waveform generator apparatus and method thereof

Abstract

A dual-mode wireless device wherein the coefficient generator (42) generates parameter values ​​for a GSM waveform using a multiplier-free multiplication operation based on a sequence of digital data values ​​transmitted from the GSM unit (34), and the waveform generator (44) utilizes The resulting parameter values ​​produce a GSM waveform. The coefficient generator includes adder sections (132, 132, 136), each having a corresponding adder (142, 144, 146) and multiplier (148, 150, 152), a register section (154, 156, 158 ), each including parameters corresponding to the modulator (48), and transmit data registers (TXDATA[5]-TXDATA[0]), which in turn receive digital data values ​​from the GSM unit. The coefficient generator generates GSM waveform parameters in response to the digital data values ​​in the transmit data register by multiplying each parameter in the register section by +1 or -1 and summing the final products to form the corresponding coefficient generator output value.

Description

technical field [0001] The present invention relates generally to waveform generation, and more particularly to methods and apparatus for generating digital waveforms in dual mode wireless devices. Background technique [0002] Many different standards and technologies exist today for operating wireless telephones. To operate well, a wireless telephone must be within the confines of a wireless telephone system that supports the same technology and is capable of operating on the same frequencies as the wireless telephone. As a result, there exist today dual mode radiotelephones designed for use in more than one radiotelephone system. For example, radiotelephones are known which are capable of operating in Advanced Mobile Phone Service (AMPS) mode and Global System for Mobile Communications (GSM). The purpose of this dual mode combination is generally to enable users to make wireless calls outside of their original service area and to increase the likelihood that the wireles...

AI Technical Summary

Problems solved by technology

These support circuits add to the size and cost of the transmitter circuit, making this approach difficult and expensive using existing technology

In addition, even if supported on the transmitter circuit 202, the high data transfer rates involved in the high-speed data transfer across the bus 204 from the output register 230 to the input register 232 of the transmitter circuit 202 will cause radio frequency interference to be fed back via the antenna. desensitize radio equipment

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