BASE BAND DECODER BASE BAND DECODER
Project Team Project Team
Gurrampati Venkatakrishna Reddy Gurrampati Venkatakrishna Reddy
Mokrala Srikrishna Chaitanya Mokrala Srikrishna Chaitanya
Under the guidance Under the guidance
Bengt Oelmann
Bengt Oelmann
BASE BAND DECODER BASE BAND DECODER
Introduction Introduction
Over view of the System Over view of the System
Coding Techniques Coding Techniques
Interfacing of the system Interfacing of the system
Results Results
Conclusion Conclusion
Introduction Introduction
The Base band decoder project is a part of ZigBee Lite Receiver.The Base band decoder project is a part of ZigBee Lite Receiver.
Zig bee is new global standard for wireless connectivity focusing on standardizing and Zig bee is new global standard for wireless connectivity focusing on standardizing and
enabling interoperability of products with in home control, building automation and industrial enabling interoperability of products with in home control, building automation and industrial control and monitoring. Most wireless sensors use too much power. By resolving this problem control and monitoring. Most wireless sensors use too much power. By resolving this problem we develop the Zigbee.
we develop the Zigbee.
The purpose of this project is to design and implement a hardware module that decodes the The purpose of this project is to design and implement a hardware module that decodes the bit-stream and convert into bytes to be transmitted.
bit-stream and convert into bytes to be transmitted.
A decoder is a device that decodes a scrambled electronic signal to make it interpretableA decoder is a device that decodes a scrambled electronic signal to make it interpretable
The function of base band decoder in zig bee is as shown below .The function of base band decoder in zig bee is as shown below .
BASE BAND DECODER BASE BAND DECODER
BASE BAND DECODER BLOCK DIAGRAM
BASE BAND DECODER BASE BAND DECODER
WISHBONE INTERFACE:
WISHBONE INTERFACE:
The interface to the microcontroller should The interface to the microcontroller should be Wishbone.
be Wishbone.
Input parameters S3 & S2 helps in Input parameters S3 & S2 helps in selecting the frequency of the data rate.
selecting the frequency of the data rate.
Input parameters S0 & S1 helps in Input parameters S0 & S1 helps in
selecting the type of coding which is to be selecting the type of coding which is to be generated.
generated.
S3 S2 Freq(Kbps)
0 0 10
0 1 20
1 0 40
1 1 80
S0 S1 Type of coding
0 0 NRZ
0 1 RZ
1 0 MANCHESTER
1 1 DIFFERENTIAL
BASE BAND DECODER BASE BAND DECODER
FREQUENCY GENERATOR:
FREQUENCY GENERATOR:
The function of whole system depends on the Frequency Generator The function of whole system depends on the Frequency Generator
Generation of Data rate Generation of Data rate
Generation of Pclk2Generation of Pclk2
Frequency Generator output is connected to the MULTIPLEXER and SERIAL to PARALLEL Frequency Generator output is connected to the MULTIPLEXER and SERIAL to PARALLEL converter
converter
Data Data
RateRate No of No of
Samples/bit Samples/bit 1010 40004000
20
20 20002000 4040 10001000 8080 500500
0 2000 4000
BASE BAND DECODER BASE BAND DECODER
• NRZ Coding:NRZ Coding:
0 -0 - Absence of the pulse Absence of the pulse 1 -1 - Presence of the pulse Presence of the pulse
NRZ coding in Base band Decoder : NRZ coding in Base band Decoder :
Data in = Data out Data in = Data out
0 1 0 0 1 1 0 0 0 1 1
RZ Coding: RZ Coding:
0 - 0 - Absence of pulse Absence of pulse
1 - 1 - Presence of pulse in the first half of the bit duration ,the light level returns to Presence of pulse in the first half of the bit duration ,the light level returns to zero during the second half
zero during the second half
RZ coding in Base band Decoder : RZ coding in Base band Decoder :
If start is set to ’1’, the arriving input is the output for twice the max value of If start is set to ’1’, the arriving input is the output for twice the max value of count.
count.
1 0 0 1 1 0 0 0 0 1 0 0 1 1 0 0 0 1 1
BASE BAND DECODER BASE BAND DECODER
Manchester coding:
Manchester coding:
0 - 0 - Upward transition at bit center. Upward transition at bit center.
1 - 1 - Downward transition at bit center. Downward transition at bit center.
1 0 0 1 1 0
Manchester coding in Base band Decoder:
•The synchronization is obtained by comparing the previous bit with any bit and also counting the duration of half pulse period.
• when transition is value occurs the count is decreased for the second half of the pulse
until it becomes ’0’ when a start bit is sent to indicate the Next pulse starting.
BASE BAND DECODER BASE BAND DECODER
Differential manchester coding:
0 - first half of the signal opposite to last half of the previous signal . 1 - first half of the signal equals to the last half of the previous signal.
Diff Manchester coding in Base band Decoder:
• The synchronization is obtained by comparing the previous bit with any bit and also counting the duration of half pulse period.
• when transition is value occurs the count is decreased for the second half of the pulse until it becomes ’0’ when a start bit is sent to indicate the Next pulse starting.
1 0 1 1 0 0 0
BASE BAND DECODER BASE BAND DECODER
Multiplexer:
Multiplexer:
Here, the 40 M-Hz clock and the data rate clock are compared. The Here, the 40 M-Hz clock and the data rate clock are compared. The
transition occurs anywhere in 40 M-Hz clock with respect to the data rate transition occurs anywhere in 40 M-Hz clock with respect to the data rate clock’s bit rate and generates the output.
clock’s bit rate and generates the output.
The output is sent to serial to parallel converter. The output is sent to serial to parallel converter.
Serial to Parallel Converter:
Serial to Parallel Converter:
It takes 1bit of data at a time as input and generates the output after 8bits It takes 1bit of data at a time as input and generates the output after 8bits of data are stored in it , parallelly.
of data are stored in it , parallelly.
The output is generated in form of serial data in (byte form).The output is generated in form of serial data in (byte form).
BASE BAND DECODER BASE BAND DECODER
RESULTS:
RESULTS:
• The outputs of matlab and vhdl are compared and both are same.The outputs of matlab and vhdl are compared and both are same.
• Total memory usage is 73300 kilobytes. Total memory usage is 73300 kilobytes.
• The decoded digital output can be obtained at four different data rates as per the requirement. The decoded digital output can be obtained at four different data rates as per the requirement.
synthesis report synthesis report::
• Number of 4 input LUTs: 585 out of 1536 10%Number of 4 input LUTs: 585 out of 1536 10%
• Minimum period: 10.688ns (maximum frequency : 93.563 MHZ)Minimum period: 10.688ns (maximum frequency : 93.563 MHZ)
• Minimum input arrival time before clock: 11.556ns Minimum input arrival time before clock: 11.556ns
Maximum output required time after clock: 5.106ns Maximum output required time after clock: 5.106ns
BASE BAND DECODER BASE BAND DECODER
Conclusion:
•We have successfully obtained the required type of decoding data at the out put as well the signal is continuos.
•Requirements of the customer have been fulfilled.
THANKS:
we thank our supervisor Bengt oelmann for his constant vigil and encouragement and all our friends for their support.
