Simulation and Implementation of Mimo-ofdm System with Stbc Using Gnu Radio and Usrp: [Essay Example], 472 words GradesFixer

Haven't found the right essay?

Get an expert to write your essay!


Professional writers and researchers


Sources and citation are provided


3 hour delivery

This essay has been submitted by a student. This is not an example of the work written by professional essay writers.

Simulation and Implementation of Mimo-ofdm System with Stbc Using Gnu Radio and Usrp

  • Category: Business
  • Subcategory: News media
  • Topic: Radio
  • Page: 1
  • Words: 472
  • Published: 27 February 2019
  • Downloads: 25
Download Print

Pssst… we can write an original essay just for you.

Any subject. Any type of essay.

We’ll even meet a 3-hour deadline.

Get your price

121 writers online

Download PDF

In MIMO systems, a transmitter sends multiple streams by multiple transmit antennas. The transmit streams go through a channel which consists of all NtNr paths between the Nt transmit antennas and Nr receive antennas. The receiver gets the received signal vector by the multiple receive antennas and decodes the received signal vectors into the original information. A flat fading MIMO system can be modeled as

y = Hx + w

Where x and y are transmitted and received signal vectors, respectively, and H and w are the channel matrix and the noise vector, respectively. x has a dimension of Nt _x1, y has dimension of Nr x 1 and H has the dimension of Nr x Nt. The ergodic channel capacity of MIMO systems in the presence of perfect instantaneous channel state information is given by

where (:)H denotes Hermitian transpose, _ is the ratio between transmit signal power and noise power, and CCSIperfect is the capacity of the MIMO system when the perfect channel state information is available. Q the optimal signal covariance and is given by Q = VSVH.

If the transmitter has no channel state information it can select the signal covariance Q to maximize channel capacity under worst-case statistics, which means Q = 1 Nt I and accordingly

To exploit the benefits offered by MIMO systems diversity coding is employed. In this paper a special type of Space Time Block Code (STBC), invented by Alamouti in 1998, is used. It was first designed for a two-transmit antenna system and is represented as a matrix:

Where * denotes complex conjugate. c1 andc2 are the symbols to be transmitted at two different time instances by two antennas. It takes two time-slots to transmit two symbols. In the first time slot, two symbols x1 and x2 (in parlance to OFDM) are transmitted simultaneously from two transmit antennas. During the second-time slot, ????x_2 is transmitted from first transmitter antenna and x_1is transmitted from second transmit antenna. The Alamouti encoder system for two transmit and two receive system is shown in Figure 4.16. Using the optimal decoding scheme discussed below, the bit-error rate (BER) of this STBC is equivalent to 2Nr-branch maximal ratio combining (MRC).

This is a result of the perfect orthogonality between the symbols after receive processing — there are two copies of each symbol transmitted and Nr copies received. Where Nr is the number of receiver antennas. This is a very special to STBC. It is the only orthogonal STBC that achieves rate-1. That is to say that it is the only STBC that can achieve its full diversity gain without needing to sacrifice its data rate. Strictly, this is only true for complex modulation symbols. Since almost all constellation diagrams rely on complex numbers. However, this property usually gives Alamouti’s code a significant advantage over the higher-order STBCs even though they achieve a better error-rate performance.

Remember: This is just a sample from a fellow student.

Your time is important. Let us write you an essay from scratch

100% plagiarism free

Sources and citations are provided

Find Free Essays

We provide you with original essay samples, perfect formatting and styling

Cite this Essay

To export a reference to this article please select a referencing style below:

Simulation and Implementation of Mimo-ofdm System with Stbc Using Gnu Radio and Usrp. (2019, February 27). GradesFixer. Retrieved January 21, 2021, from
“Simulation and Implementation of Mimo-ofdm System with Stbc Using Gnu Radio and Usrp.” GradesFixer, 27 Feb. 2019,
Simulation and Implementation of Mimo-ofdm System with Stbc Using Gnu Radio and Usrp. [online]. Available at: <> [Accessed 21 Jan. 2021].
Simulation and Implementation of Mimo-ofdm System with Stbc Using Gnu Radio and Usrp [Internet]. GradesFixer. 2019 Feb 27 [cited 2021 Jan 21]. Available from:
copy to clipboard

Sorry, copying is not allowed on our website. If you’d like this or any other sample, we’ll happily email it to you.

    By clicking “Send”, you agree to our Terms of service and Privacy statement. We will occasionally send you account related emails.


    Attention! this essay is not unique. You can get 100% plagiarism FREE essay in 30sec

    Recieve 100% plagiarism-Free paper just for 4.99$ on email
    get unique paper
    *Public papers are open and may contain not unique content
    download public sample

    Sorry, we cannot unicalize this essay. You can order Unique paper and our professionals Rewrite it for you



    Your essay sample has been sent.

    Want us to write one just for you? We can custom edit this essay into an original, 100% plagiarism free essay.

    thanks-icon Order now

    Hi there!

    Are you interested in getting a customized paper?

    Check it out!
    Having trouble finding the perfect essay? We’ve got you covered. Hire a writer uses cookies. By continuing we’ll assume you board with our cookie policy.