Wireless Sensor Network can be considered to be energy constrained wireless scenarios, since the sensors are operated for extended periods of time, while relying on batteries that are small, lightweight and inexpensive. Energy constrained wireless application is done with the help of Lookup Table-log-BCJR (LUT-Log-BCJR) architecture. In our existing system the conventional LUT-Log-BCJR architecture have wasteful designs requiring high chip areas and hence high energy consumptions Energy constrained applications. This motivated our proposed System the LUT log BCJR is designed with Clock gating technique achieves low-complexity energy-efficient architecture, which achieves a low area and hence a low energy consumption, and also achieving a low energy consumption has a higher priority than having a high throughput. we use most fundamental Add Compare Select (ACS) operations and It having low processing steps, so that low transmission energy consumption is required and also reduces the overall energy consumption.