Legerity, Inc.

Advanced Micro Devices Corporation

Eddy Kent Bell

Stephen T Janesch

Javier V Magana

William R Finch

Javier V Maga&ntilde;a

In the broadcast band having a plurality of channels allocated therein, by using high-side injection and low-side injection as described herein, the noise introduced into the channel by the local oscillator signal can be minimized. The local oscillator signal in combination with the intermediate frequency determines the frequency of the channel signal being produced by the transmitter. The selected high-or low-side injection determines whether the bulk of the power is introduced into the combination frequency signal (i.e., the channel) above or below the local oscillator frequency, thereby moving the local oscillator frequency outside the broadcast band. The non-selected sideband is even further outside broadcast band.

Apparatus and method for broadcast band noise reduction in a transmitter with a low IF frequency

In order to reduce the noise components in a multiplexed communication system, noise components generally referred to as splatter that from the rapid transition between the transmitting state and the non-transmitting state, this power transition in the transmitted signal is provided with a ramped envelope. In the preferred embodiment, the ramped power transition is the result of a ramped enabling signal applied to the power amplifier generating the transmitted signal. The use of a ramped power transition reduces the noise introduced as a result of an abrupt power transition. In addition, the transmitted signal is provided with a preamble so that no data is transmitted during the transition period.

Apparatus and method to reduce power amplifier noise generation in a multiplexed communication system

A digital cordless telephone communicates with a telecommunications network over a wire link and receives first communications signals from and delivers second communications signals to the telecommunications network. The digital cordless telephone includes a cordless fixed part connected to the wire link for receiving the first communications signals from the telecommunications network and for sending the second communications signals to the telecommunications network over the wire link. The cordless fixed part also transmits the first communications signals, together with first control information generated by the cordless fixed part, including a channel identifier indicative of a desired radio frequency communication channel, and receives the second communications signals, together with second control information. The cordless portable part transmits the second communications signals, together with the second control information generated by the cordless portable part, including the channel identifier and a second recipient identification, for receipt by the cordless fixed part, and receives the first communications signals, together with the first control information, from the cordless fixed part. The telephone includes a fixed part memory for receiving the second control information and a portable part memory for receiving the first control information. A fixed part microcontroller generates the first control information, including the channel identifier, and controls the cordless fixed part to transmit the first communications signals over the desired radio frequency communication channel. A portable part microcontroller reads the channel identifier and controls the cordless portable part to transmit the second communications signals over the desired radio frequency communication channel based on the channel identifier.

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Round Rock, TX, United States of America

Eddy Kent Bell