Assignment First

  本篇案例研究代写-HARQ与FEC的比较讲了FEC和HARQ的另一个不同之处在于,HARQ只会导致信道容量的百分之几的扩展,以实现对任何类型错误的可靠保护。在FEC的情况下,通常会扩大一半或更多的总通道容量,以改善该通道。在HARQ的情况下,第一次传输通常只包括数据和错误检测。如果发现发送的消息没有错误,则对其进行处理。本篇案例研究代写文章由英国第一论文 Assignment First辅导网整理,供大家参考阅读。

  Comparison between HARQ and FEC

  Another difference between FEC and HARQ is that HARQ only leads to the expansion of few percent of the capacity of the channel for the purpose of reliable protection against any kind of error. In case of FEC there is an ordinary expansion of the half or more of the total channel capacity for the improvement of the channel. In case of HARQ the first transmission generally consists of only the data and error detection. In case the transmitting message is found to be error free, it is processed (Gungor& Hancke, 2009). In case an error is found in the message, FEC parities will be there in case of second transmission. If the same is free from all kind of error, it can be done by the process of combination of the information which may be received from both the transmissions. There may be at times that the simple HARQ may lead to the loss of the capacity in case of strong signal conditions. Though, this is not possible in case of Type 2 HARQ, as the FEC bits are not exactly transmitted but there is also a requirement of various subsequent transmissions.

  The basic applications of HARQ may be observed in case of HSDPA and HSUPA where is a requirement of data transmission at very high speeds in case of mobile networks which may include UTMS network. In addition to this, it can also be used in, which is a high speed local area network. It has the ability to operate at the data rates which are up to 1 Gbit/s. Some of the common examples of FEC systems are the ones which uses the turbo codes. These codes may be maintained at a constant rate which is equal to the code rate R.