Skip to main content
Share Your Experience: Take the 2024 Developer Survey
8 votes
Accepted

SC-FDMA in LTE system

First of all, in refering to standard specification, please mention the version because the numeration between versions can be different. My answer should be only a comment but I think with images it ...
AlexTP's user avatar
  • 6,595
6 votes

Why is LTE either FDD or TDD?

You are mixing two things modulation and multiple access. SC-FDMA has been chosen because it is battery-friendly modulation. SC-FDMA is used in both FDD and TDD modes. There are several reasons why ...
AlexTP's user avatar
  • 6,595
3 votes
Accepted

SC-FDMA disadvantages

Some more disadvantages: Channel estimation using pilots is harder, because you do not have orthogonal data on each frequency bin, compared to OFDM. That's why e.g. LTE uplink resorts to a midamble ...
Maximilian Matthé's user avatar
2 votes
Accepted

For a 20 MHz channel, with 1200 usable subcarriers(18 MHz occupied), what should be the size of the FFT on the transmitter before IFFT is applied?

We perform M point FFT on each Q block, then map the FFT results to intended positions of 1200 available subcarriers (subcarrier mapping), which are finally the input of a 2048-iFFT operation. See the ...
AlexTP's user avatar
  • 6,595
1 vote

SC-FDMA vs single carrier signal PAPR

Consider some actual use cases for further insight: Unmodulated Carrier: The peak to average ratio is 3 dB given the relationship between the rms and peak level of a sine wave. Unfiltered Single-...
Dan Boschen's user avatar
  • 52.1k
1 vote

Why is LTE either FDD or TDD?

Agree with the other answer that the question is mixing up concepts. TDD/FDD has nothing to do with the multiple access provided by OFDMA. TDD/FDD is about duplexing, which is, how the traffic in the ...
auspicious99's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible