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Clearwire Corporation (CLWRD) Message Board

  • indano indano Dec 28, 2012 8:13 AM Flag

    Nearly Blind - TD-LTE Vision Restored

    If your next pair of glasses allowed you to see through walls, you'd buy no others.
    If Techroline DOUBLED your gas mileage, you'd buy no other.
    The changes TD-LTE brings to Clearwire spectrum are game changing.
    TD allows for beam-forming, a huge range extender and not practical for FDD.
    Uplink modulation change (Sc-FDMA) lowers peak-to-avg ratio allowing for greater handset TX level while extending battery life.

    Cell site range is limited to how far away a handset can be and still be 'heard' by the cell site.
    worth repeating...
    Cell site range is limited to how far away a handset can be and still be 'heard' by the cell site.

    TD-LTE with SC-FDMA are HUGE Range Extending and Penetraton Improving technologies. Shareholders should be allowed to see, to experience these GAME CHANGING technology improvements BEFORE being asked to vote.

    Clearwire has sufficent assets to turn-on 5000 TD-LTE cell sites and should do so BEFORE shareholders vote. Any less is FRAUD.

    The major minority share holders know what I say to be true. Sprint will not be allowed to steal CLWR.

    Motorola White Paper
    SC-FDMA also has a low power amplifier de-rating (Cubic Metric / PAPR) requirement, thereby conserving battery life or extending range

    Agilent White Paper
    SC-FDMA is a hybrid transmission scheme combining the low peak to average (PAR) of single carrier schemes with the frequency allocation flexibility and multipath protection provided by OFDMA. This result defines why SC-FDMA was developed. It clearly shows that for this 16QAM example the CCDF is several dB below the Gaussian reference line which is what OFDMA would have given. This extra headroom lowers costs in the power amplifier, reduces battery drain and extends the range of handset uplink.

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    • Do you really know why SC-FDMA uses less power and why it has been set up only with a single carrier channel?

      The SC-FDMA does not require continuous power source feeding because in an OFDMA (downlink) it requires a continuous power source due to multiple transmissions simultaneously through MIMO and this phenomenon worsen significantly when it’s 4x4 because it requires to interact with the network to eliminate the tear-down/set-up time thereby becomes a power drain to the battery.

      Secondly, SC-FDMA has been set up as a single carrier channel because how much of an 'upload' does a mobile user do therefore your point about range extension is worthless unless you are transmitting video out of your smartphone/tablet all the time rather than watching (down-streaming) video like normal subscriber does. The reason SC-FDMA is not used in FDD-LTE is because of its symmetrical channel setup on both directions (UL/DL), thereby requires OFDMA on both.

      Do you really understand what you are talking about? Perhaps you should stop your non-sense, amateur!

      • 1 Reply to sunnybeach73
      • Hey Bozo, SC-FDMA re-orders the TX bits across carriers to maintain low peak-to-average ratio of TX (uplink) signal.
        Lower PAR allows reduced PA bias levels (you know the old AC load line) or increase in TX power without degrading the ACP (adjacent channel power) performance.
        I was designing PAs while you were still suckling mommies teets.

        Despite its name, Single Carrier Frequency Division Multiple Access (SC-FDMA) also transmits data over the air interface in many sub-carriers but adds an additional processing step. Instead of putting 4 bits together as in the OFDM example to form the signal for one sub-carrier, the additional processing block in SC-FDMA spreads the information of each bit over all the sub-carriers. This is done as follows: Again, a number of bits (e.g. 4 representing a 16 QAM modulation) are grouped together. In OFDM, these groups of bits would have been the input of the IDFT. In SC-FDMA, however, these bits are now piped into a Fast Fourier Transformation (FFT) function first. The output of the process is the basis for the creation of the sub-carriers for the following IFFT.

        Summary of the difference between OFDM and SC-FDMA:

        OFDM takes groups of input bits (0's and 1's) to assemble the sub-carriers which are then processed by the IDFT to get a time signal. SC-FDMA in contrast first runs an FFT over the groups of input bits to spread them over all sub-carriers and then uses the result for the IDFT which creates the time signal. This is why SC-FDMA is sometimes also referred to as FFT spread OFDM.

        While SC-FDMA adds additional complexity at both the transmitter and receiver side, the 3GPP standardization body has nevertheless decided for it as treating signal this way reduces the Peak to Average Power Ratio (PAPR). This is important to lower the power consumption of mobile devices.

        What TD-LTE brings to 2.6 GHz is a BIG DEAL. Don't let any of the clowns on this blog tell you otherwise.

        $8+ or NO on Buyout !!!

    • These technical factors have been in development for over a decade and made part of the standards.. and are now irrelevant to CLWR stock except as part of the argument that the stock value should be higher.

      Yep, you point out the stuff that was being figured out years ago and is now built into the new wireless network equipment and devices. However, Clearwire is no longer a going concern to do anything with that technology because they failed to do enough with the prior first generation of OFDMA technology and market window.

      Good luck.

      • 1 Reply to teamrep
      • If you beleived your own babble you'd have left long ago.
        Your mere continued presence on this thread reinforces my posts.
        CLWR will have to deploy TD-LTE before a vote. Any less constitues fraud.
        CLWR already indicated they have the $$$ to upgrade 5000 sites and the Sprint contract for LTE.
        We will see $6+ for sure!!!!! - or - NO DEAL
        I predict $2.97 + 1 share of Sprint.

    • NSN: TD-LTE Coverage
      Clearwire has the bandwidth to support 8-pipe radio.

      Clearwire MUST turn-on the 5000 TD-LTE cell sites (line card upgrade) before shareholders vote.
      Anything less is FRAUD!!!
      It is obvious that TD-LTE greatly enhances Clearwire spectrum capabilities. This is being hidden from shareholders!!!!

      Nokia Siemens Networks TD-LTE solution includes a number of unique features that dramatically expand capacity and coverage - for example, our 6-sector site capability delivers up to 80% more capacity and 40% more coverage than typical 3 sectors systems.

      The Nokia Siemens Networks TD-LTE solution begins with our high capacity Flexi Multiradio 10 Base Station built with broad range of radio options such as our newest TD-LTE 4-pipe radio module, TD-LTE 6-pipe radio module and TD-LTE 8-pipe radio module. It also includes our industry high capacity baseband - Flexi Multiradio system module. The Flexi Multiradio system module is unique with its integrated transport module, LTE-Advanced capability, and is capable of delivering up to 10Gbps capacity in a Liquid Radio baseband pool architecture.

      Nokia Siemens Networks' 4 pipes radio provides four key benefits:

      Suitable for high-capacity base station sites.
      Delivers 50% more transmit power in the "4 transmit and 4 receive" category, which significantly extends the average sector throughput in urban coverage areas, as well as providing optimum coverage in large rural areas.
      Only radio frequency module in the "4 transmit and 4 receive" category that can deliver a transmit power of 60 watts for two carriers, thus providing unprecedented capacity when needed.
      Reduction in infrastructure requirements - sites, towers, etc. - as well as power consumption because it serves a larger area with a combined high transmit power of 120 watts and high receive sensitivity.
      In addition to supporting LTE, 4 pipes radio can be upgraded via a simple software update to support LTE-Advanced features like 40 MHz carrier aggregation.