Background Information

Contents

Background

Defination of 4G

Block Diagram

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Block Diagram
It defines the input data which we need to transmit over the channel. It can be any like audio, video, text data, audio and video together.
It converts the input data like audio, video, text data to binary (0/1) data for transmission.
It is used to match the input data rate and channel data rate.The component?s design approach is called FEC (Forward Error Correction). This approach allows us to detect and correct the bit stream. It is important to bear in mind that the correction and detection of errors are not absolute but rather statistical. Thus our goal (as usual) is to minimize the BER. In this method, K original bits, which are also called informational bits, are replaced with new N>K bits called code bits. The difference N-K represents the redundancy that has been added to the informational bits. The manner in which we produce the code bits is called channel code or ECC (Error Correcting Code).
We need to convert our data to parallel as here we are doing modulation of multiple bits simultaneously.
Here modulation is done by digital modulation schemes there are diff types of digital modulation schemes like BPSK, QPSK, 8PSK, 16PSK, 8QAM, 16QAM, 32QAM, 64QAM etc.
IFFT converts the frequency domain waveforms into time domain. And as here we need to add the guard interval so we need the waves to be in time domain.
This block converts the parallel data into serial form as in next step we need to insert the guard time for that we have an data into serial form.
Between every sub channel the guard interval is there to reduce the ISI (Inter Symbol Interference).
channel is a medium used to convey the information between transmitter and receiver.
Used to remove the guard interval inserted between two sub channels.
Main this block converts the signals form the time domain to frequency domain.
Demodulation blocks remove the subcahnnel carrier from received signal
After demodulation the signal should be in the sequence. This is performed by parallel to serial
This block performs the digital to analog conversation.
At the end of this block we get our original (transmitted) signal back.

Single carrier approach & Multi carrier approach

Difference between FDM and OFDMA

OFDMA Multi User Access

Definition of slot

Down link zone

Down link zone

Steps of OFDMA data mapping:

  1. Segment the data after the modulation block into blocks sized to fit into one OFDMA slot.
  2. Each slot shall span one or more subchannels in the subchannel axis and two one or more OFDMA symbols in the time axis, as per the slot definition. Map the slots such that the lowest numbered slot occupies the lowest numbered subchannel in the lowest numbered OFDMA symbol.
  3. Continue the mapping such that the OFDMA subchannel index is increased. When the edge of the Data Region is reached, continue the mapping from the lowest numbered OFDMA subchannel in the next available symbol.

Up link zone

Up link zone

Steps for OFDMA data mapping

  1. Segment the data into blocks sized to fit into one OFDMA slot.
  2. Each slot shall span one or more subchannels in the subchannel axis and one or more OFDMA symbols in the time axis, as per the slot definition. Map the slots such that the lowest numbered slot occupies the lowest numbered subchannel in the lowest numbered OFDMA symbol.
  3. Continue the mapping such that the OFDMA symbol index is increased. When the edge of the UL zone (which is marked with Zone_switch_IE) is reached, continue the mapping from the lowest numbered OFDMA symbol in the next available subchannel.
  1. Map the slots such that the lowest numbered slot occupies the lowest numbered subchannel in the lowest numbered OFDMA symbol.
  2. Continue the mapping such that the Subchannel index is increased. When the last subchannel is reached, continue the mapping from the lowest numbered subchannel in the next OFDMA symbol that belongs to the UL allocation. The resulting order is shown by the arrows in Figure.

OFDMA frame structure

OFDMA frame structure

Advantages

QOS Management

Services UGS RTPS NRTPS BE UGS/AD
Real time service(e.g.VoIP) Real time service(e.g. MPEG) Non real time service(e.g. File transfer) Provides best service among all When UGS in inactive UGS/AD will become active
Fixed size data packet Variable size data packet variable size data packet(High B\W FTP) combination of UGS and RTPS
Eliminate overhead & latency NA NA Overhead and latency
BS must provide fixed size of data grants SS specify the size NA SS not prohibited for argument BS must provide fixed size when activated as UGS and variable size when activated as RTPS
SS prohibited for arguments SS prohibited for arguments, SS prohibited for argument SS prohibited not for argument
BS prohibited for unicast BS only providede with unicast BS provides periodic unicast on regular basis even during congestion Multicast when activated as UGS and unicast when activated as RTPS
Parameters: Unsolicited Grant Size Nominal Polling Interval Nominal Polling Interval Minimum Reserved Traffic Rate Nominal Polling Interval
Grants Per Interval Minimum Reserved Traffic Rate Minimum Reserved Traffic Rate Traffic Priority Nominal Grant Per Interval
No piggyback requests No piggyback requests Traffic Priority Piggyback allowed Piggyback allowed
Nominal Grant Per Interval Unsolicited Grant Size

Comparison between conventional invention and present invention

QoS

Network entry and initialization


Signalling diagram for Authentication

Ranging

Ranging is the process which measures state of channel between Mobile station(MS) and Base station(BS).

Need

Adjusting a correct time offset between a transmitter, e.g., an MS, and a receiver, e.g., a Base Station (BS), and for controlling power in an UpLink (UL).

Ranging Procedure:

  1. The mobile station receives uplink transmission parameters after acquiring downlink synchronization.
  2. The mobile station selects one of slots of ranging subchannels allocated within a frame structure and forwards ranging request message (RNG-REQ) to the base station using an initial ranging code.
  3. The base station receives the ranging request message and forwards all of required transmission parameter adjustment values and status information to the mobile station through ranging response message (RNG-RSP).
  4. If the status information indicates 'success,' the base station allocates uplink bandwidth for CDMA Allocation IE required to allow the mobile station to transmit the ranging request message (RNG-REQ). If the status information indicates 'continue,' the mobile station returns to the step 2) and repeats the steps until the status information indicates 'success.'
Ranging pocedure

Parameters

SR. NO QoS Patent no.
Conventional Invention Present Invention
1 Basic conventional TTI was not adaptable,it was concept of fixed TTI. Here by knowing the protocol service used in QOS adaptivity is possible in TTI. EP1816807A1
2 Pilot signals are too less in uplink signals as compared to downlink so QOS is decreased. Using precoding matrix determiner we can increase the pilot signals. EP1816815A1
3 Time consumed to transmit data from MAC layer to PHY layer is more. Time consumed here is less as here the ARQ retransmission timer will start after HARQ retransmission. EP1821446A2
4 Subscriber selects cluster as per the BS broadcast of the pilot carrier Subscriber selects one or more Cluster using the the SINR value and low traffic loading of pilot carrier US7164669B2
5 Subscriber selects one or more Cluster using the the SINR value and low traffic loading of pilot carrier to increase the quality. Here SINR value, Base station ID, frequency of physical channel, and the channel quality measurement information are required to increase the quality. EP1473956A2
6 Subscriber station authentication method, a protocol configuration method, and a device thereof in a wireless portable Internet system for allowing authentication was not allowed during handover. Authentication from subscriber station in wireless portable network system is allowed, comprises of two steps: (1) SS transmitts basic capability negotiatiiion message (SBC-REQ) to BS. (2) SS receives a reply message (SBC-RSP) on the basic capability negotiation message from the BS. US20070210894
7 BS allocates resources to the MS on the assumption that MS is in the worst channel so BS cannot know the channel state of an MS. The initial ranging is performed after a BS request in order to acquire synchronization between the BS and the MS on the basis of UL-MAP with IE. US20070202882
8 In conventional invention for ranging response RNS_RSP signal is needed. That is nothing but delay in the uplink traffic transmission. 1.) Reducing the delay in uplink data transmission of portable subscriber station by including a ranging parameter for bandwidth request code in UL_MAP and eliminating RNG_RSP.

2.) In addition ranging process additionally performed with bandwidth request.

WO2007037633

Frame structure

SR. NO Frame structure Patent no.
Conventional Invention Present Invention
1 Switching noise in the oscillation signal can?t be removed and detection of the failure was not possible. Isolation circuit is provided to reduce the effect of the switching noise and alarm circuit is also provided for the detection of the failure of the oscillation signal. WO2007083924A1