 Seal membrane with integral microphone support |
| OF THE PREFERRED EMBODIMENT Referring now to the drawings and in particular to FIG. 3, a unitarily ... |
|
| Weatherproof electronic keypad with replaceable graphics overlay |
| An electronic keypad according to the invention comprises a plastic housing that includes a ... |
|
| Splash water protected keyboard |
| In a splash-water protected keyboard having a contact foil arranged in a housing and a rubber mat ... |
|
| Keyboard assembly |
| It is therefore an object of this invention to provide a keyboard assembly with a water-resistant ... |
|
| Tape printing apparatus |
| It is an object of the invention to provide a tape printing apparatus which is capable of ... |
|
| Body composition analyzer |
| We claim: 1. A body composition analyzer comprising: a plurality of electrodes attachable to the ... |
|
| Frequency regulation of an oscillator for use in MWD transmission |
| The present invention addresses these and other drawbacks in the art by creating an oscillating ... |
|
| Membrane key switch with anti-inversion feature |
| The present invention relates to a matrix key switch of the membrane type wherein there are ... |
|
| Method of teaching transmitter codes to remote receivers |
| In a disclosed embodiment of this invention, the signal to place the receiver in programming mode ... |
|
|
Intelligent encoding method for wireless data communication and control
| Details |
Inventors: Wang, Lichen; Yeh, Keming W.;
Assignee: ActiSys Corporation (Fremont, CA)
Primary Examiner: Tse; Young T.
Assistant Examiner:
Attorney, Agent or Firm: MacPherson Kwok Chen & Heid LLP
A method includes a data encoding scheme that has a run length limit of (1,6) and a 25% duty cycle. With error correction, the method achieves an effective run length limit of (2,9). The method can be used in conjunction with a packetized communication protocol to allow multiple controllers to communicate with multiple peripheral devices in a wireless data network. Peripheral devices include pointing devices, keyboards and game pads. |
|
DETAILED DESCRIPTION The present invention provides a method for encoding a bit stream into symbols for transmitting over a wireless communciation link that has a fixed duty cycle and a run length limit (d, k), in which d is greater than 0.
With error correction capability included in the decoding process, the resulting effective run length limit can be further increased.
The present invention is suitable for use in infrared application and RF application, even at low bit rates.
In one embodiment of the present invention, an encoding schme is provided which includes a state machine having a first state, a second state and a third state, each state being associated with a different group of symbols.
In each group of symbols are state transition symbols.
The encoding scheme uses this state machine to guide encoding data bits.
When a state transition symbol is generated, the state machine also changes state.
In one implementation, 4-bit symbols are used, with each symbol in the first group of symbols provided a ratio of logic `1` bits to logic `0` value bits equaling 3 to 1, and each symbol in the third group of symbols having a ratio of 2:2 and one symbol in the second group being {0000}.
In that implementation, the state machine goes into the second state to avoid the current symbol from being followed by another symbol in the first group to create consecutive logic `1` value bits.
Also, in that implementation, the state machine, after issuing the {0000} symbol, enters the third state, so as to allow the higher duty cycle symbols in the third group to maintain an overall average duty cycle of 25%.
In that implementation, the code dictionary includes error correction capability to extend said run length limit to an effective run length limit of (2,9).
The encoding scheme of the present invention can be used in a wireless communication system.
In one such system, a controller capable of sending a polling packet having an identification field is provided, so that multiple devices, each identified by a unique identification specified in the polling packet can respond by sending a response packet returning device-specific information (e
|
|
Coded 
