The coding mode is called Regular Pulse Excited-Long Term Prediction (RPE-LTP). It works as follow: 8KHZ of sampling is performed first, then divided into frames with 20ms; every frame has 4 sub-frames; the duration of every sub-frame is 5ms; and the pure bit rate is 13kbit/s. The voice compression coding technique is widely used in … Read more
Typically, the data rate available at the radio interface is lower than the data rate available on the network interfaces. Thus, when a certain rate data service is higher than the data rate of the LTE radio interface, this leads to buffering in the UE and the eNodeB. This buffer allows the programmer to the … Read more
Here I write Interference Margin in simple word and basic definition of interference margin in LTE. Let understands it. Interference margin accounts for the increase in the terminal noise level caused by the interference from other users. LTE uplink is orthogonal if it is within the same cell so there is no intra-cell interference. However, … Read more
When multiple strong signals with different frequencies enter a receiver at the same time, the inter modulation product at the receiver is generated by the signals by the front end due to the non-linear circuit of the receiver. Unfortunately, the frequency of the inter modulation product drops into the useful frequency band of the receiver … Read more
Spurious interference Spurious interference refers to the additive interference generated by the interference source in the working frequency band of the interfered receiver. Spurious interference includes the out of band power leakage of the interference source, amplified background noise, and transmit inter-modulation product. Spurious interference can reduce the signal noise ratio (SNR) of the interfered … Read more
The concept of Interference Rejection Combining (IRC) is to regenerate the transmitted signal based on the estimated data from the previous receptions, emulate the distortion occurring from the multi-path channels and, finally subtract all regenerated interfering signals from the uplink received signals to obtain more reliable estimation of original users’ data. This feature utilizes the … Read more
It is difficult to separate Adjacent Channel Leakage power Ratio and Adjacent channel selectivity because they coexist. therefore, Adjacent Channel Leakage power Ratio and Adjacent channel selectivity are usually considered together. The result of the consideration is Adjacent Channel Interference Ratio (ACIR) and Adjacent Channel Interference Ratio is the ratio of the total power transmitted … Read more
Adjacent channel selectivity Adjacent channel selectivity (ACS) is a protection index to determine the capability of a receive filter. Adjacent channel selectivity refers to the capability to receive the power of the local in band channel when the interference signal from the adjacent frequency exists. Adjacent channel selectivity is the ratio of the receive filter … Read more
Here I write about a simulation analysis of the system performance deterioration caused by the following four types of interference: eNodeB->UE, UE->eNodeB, eNodeB->eNodeB, and UE->UE when two systems are not co-located. From simulation result with no filtering, when the eNodeBs are not co-located, the most serious interference is from eNodeB->eNodeB. The network coverage and capacity … Read more
Margin sites intrusive noise levels due to an increase can be considered as If sites were spaced closer together than position using the same frequency The thermal noise floor. In other words, the system is interference limited as Opposed to limit noise. Often a site link budget maximum range is used to evaluate the process. … Read more