Frequency Hopping

When the voice signal is transmitted after being processed and modulated, the frequency hopping technique will be used too, i.e. the transmission carrier varies constantly at different timeslots (of course, the variation should comply with the frequency planning principles). The frequency hopping spread spectrum (FHSS) is a method for quickly switching the transmission of radio … Read more

Categories GSM

What is Interleaving

  If the voice signal is modulated and transmitted directly after channel coding, due to the condition changes in mobile communication channel, a deep of the fading will influence a successive string of bits and cause high bit error rate. If the bits of a successive string are interfered or lost, the other end of … Read more

Categories GSM

What is Channel Coding

To check and correct errors during the transmission, redundancy data and the information calculated from the source data are added to the stream so as to increase the bit rate. For the voice, the length of these codes is 456 bits every 20ms. The bit rate of code stream output from the voice coder is … Read more

Categories GSM

Affects of the Channel in LTE MIMO

Affects of the Channel in LTE MIMO To understand the impact of the channel, let’s assume that the base station receiver is facing many challenges in the same MIMO receiver that universal areas, but also must receive data simultaneously from multiple users. In terms of MIMO UM, each signal is derived from a separate UE, … Read more

How Cross domain signal analysis in LTE

How Cross domain signal analysis in LTE Regarding cross domain analysis, we see that, I traditionally signal from a receiver RF section can be demodulated and Q components using analog techniques. Today, however, the down conversion signal is digitized by an ADC IF, and usually then fed into the section of the baseband demodulation and … Read more

Wide bandwidths concept for LTE MIMO

Wide bandwidths concept for LTE MIMO One of the unique aspects of LTE is the support of the six channel bandwidths from 1.4 MHz to 20 MHz. To simplify system operation and roaming phones should support all these bandwidths, although effective deployment in any one area may be limited to fewer band width 20 MHz … Read more

Open loop and close loop testing in LTE

Here I write short notes on how to test open loop and close loop testing in lte and what idea behind it. In open loop no any data send back and in closed loop all relevant data available to both side lets check in some detail. Open and close loop testing in LTE: Open loop … Read more

Receiver Design for LTE

Receiver Design for LTE The main objective of the study is to take action for the entire measurement receiver. However, many factors can affect the performance of the receiver, such sub-blocks of receipt must be checked on the basis of the first and measurable contributions eliminate or reduce uncertainty. If using multiple receivers, it is … Read more

Basic Test for LTE Transmitter and Receiver Design

Basic Test for LTE Transmitter and Receiver Design LTE already requires fundamental changes in the base and handset and research project due to higher data rates, there is an important signal bandwidth and enhance integration and miniaturization in mobile phones, for example: Need to handle 6 different channel bandwidth from 1.4 to 20 MHz, and … Read more

Single and Multiple User MIMO in the Uplink SU MIMO LTE

Single and Multiple User MIMO in the Uplink SU MIMO LTE SU-MIMO is within LTE, but at the time of this writing has not yet been fully identified. To implement the SU-MIMO UE require two transmitters. This is an important problem from the standpoint of cost, size and battery consumption, and for these reasons, SU-MIMO … Read more