How to understand the timeslot structure of the LTE physical layer, RE and RB

Problem:
1. Resource particle Re, used (k,l) to identify the coordinates of the time domain in the frequency domain, how to understand.

A: K is the number of the sub-carrier of the resource raster, L is the SC-FDMA ordinal in the time slot

2. A RB has n time-domain continuous SC-FDMA symbols and a continuous sub-carrier composition in the frequency domain. What a SC-FDMA symbol refers to. is the number 0 or 1. or a modulator (for example, 8-in modulation, 8-frequency shift keying, this symbol is a modulated waveform, but it represents 3bit, such as 001).
A: A RB has 7*12 re, that is, there are 7 OFDM symbol, each OFDM symbol is a 12 sub-carrier overlay, each re is a QAM modulation symbol, SC-FDMA symbol should be modulated on all sub-carriers of the sum of the complex value data

3. A time slot in the time domain, corresponding to a lot of frequency domain sub-carrier, how to understand.

A: Upstream is similar, and the difference is that the modulation is done in the time domain, and then once more DFT, transformation to the frequency domain, as well as all the different frequency points of the sub-carrier overlay becomes SC-FDMA symbol, because the modulation is done in the time domain, so the uplink of a UE data can be regarded as a single carrier,  So called SC-FDMA. A SC-FDMA symbol corresponds to the 12*NRB sub-carrier, and a time slot consists of 7 SC-FDMA symbols.

4. For example, this re, which is assumed to be re (2,3), represents the third Sc-fmda symbolic symbol of the 2nd sub-carrier on the time domain. What this symbol is. is a waveform of physical space transfer. or a digital amount.
A: The assumption is re (2,3), which represents the 3rd Sc-fmda symbol in the time domain. This symbol is a waveform of physical space transmission.

Rb,resource block, a resource block, is the scheduling unit for business resources in LTE.
The RB consists of 12 successive sub-carriers with a bandwidth of 180kHz and a duration of 1ms (equivalent to 1 sub-frames and 2 time slots).

The number of RB is correlated with the bandwidth of the frequency, with a bandwidth of 20MHz of 100 Rb,10mhz with 50 RB. P.s
The long-term evolution of the EPS:UMTS and the evolution of the system structure mentioned in the book that RB can contain 25 sub-carriers. Later checked, roughly on the R7 when the evaluation of the use of 25 sub-carriers, and then unified to 12, and GSM approach.

In the 3GPP LTE and LTE-A standards, it is generally considered 1tti=1ms. That is, the size of a subframe (sub-frame =2slot), which is the basic unit of time governed by wireless resource management (dispatch, etc.).