SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D/A

(Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO

§ 240.13d-1(a)

(Amendment No. 14)*

CLEARWIRE CORPORATION

(Name of Issuer)

Class A Common Stock

(Title of Class of Securities)

18538Q 105

(CUSIP Number)

Michael J. Egan

King & Spalding LLP

1180 Peachtree Street, N.E.

Atlanta, Georgia 30309

(404) 572-4600

(Name, address and telephone number of Person

Authorized to Receive Notices and Communications)

Gary D. Friedman

Friedman Kaplan Seiler & Adelman LLP

7 Times Square, 28^th Floor

New York, New York 10036

October 13, 2012

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box:  ¨

NOTE: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See § 240.13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (the “Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

(Continued on following pages)

This Amendment No. 14 (this “Amendment”) is being filed by the Sprint Entities and the ERH Entities (each, as defined below) and amends and supplements the Statement on Schedule 13D which was jointly filed on December 5, 2008, as amended by Amendment No. 1 to the Statement on Schedule 13D which was jointly filed on February 27, 2009, as amended by Amendment No. 2 to the Statement on Schedule 13D which was jointly filed on November 12, 2009, as amended by Amendment No. 3 to the Statement on Schedule 13D which was jointly filed on December 22, 2009, as amended by Amendment No. 4 to the Statement on Schedule 13D which was jointly filed on December 7, 2010, as amended by Amendment No. 5 to the Statement on Schedule 13D which was jointly filed on December 14, 2010, as amended by Amendment No. 6 to the Statement on Schedule 13D which was jointly filed on May 13, 2011, as amended by Amendment No. 7 to the Statement on Schedule 13D which was jointly filed on June 8, 2011, as amended by Amendment No. 8 to the Statement on Schedule 13D which was jointly filed on December 16, 2011, as amended by Amendment No. 9 to the Statement on Schedule 13D which was jointly filed on February 24, 2012, as amended by Amendment No. 10 to the Statement on Schedule 13D which was jointly filed on March 14, 2012, as amended by Amendment No. 11 to the Statement on Schedule 13D which was jointly filed on June 15, 2012, as amended by Amendment No. 12 to the Statement on Schedule 13D which was jointly filed on September 14, 2012 and as amended by Amendment No. 13 to the Statement on Schedule 13D which was jointly filed on October 3, 2012 (collectively, the “Schedule 13D”) on behalf of Sprint Nextel Corporation, a Kansas corporation (“Sprint”), Sprint HoldCo, LLC, a Delaware limited liability company (“Sprint HoldCo” and together with Sprint, the “Sprint Entities”), Comcast Corporation, a Pennsylvania corporation (“Comcast”), Comcast Wireless Investment, LLC, a Delaware limited liability company (“Comcast LLC” and, together with Comcast, the “Comcast Entities”), Bright House Networks, LLC, a Delaware limited liability company (“BHN”), BHN Spectrum Investments, LLC, a Delaware limited liability company (“BHN Spectrum”), Newhouse Broadcasting Corporation, a New York corporation (“NBCo”, and collectively with BHN and BHN Spectrum, the “BHN Entities”), Eagle River Holdings, LLC, a Washington limited liability company (“ERH”) and Craig O. McCaw, an individual (“Mr. McCaw” and, together with ERH, the “ERH Entities”), with respect to the Class A common stock, par value $0.0001 per share (the “Class A Common Stock”), of Clearwire Corporation, a Delaware corporation (“Clearwire” or the “Issuer”). We refer to the Sprint Entities and the ERH Entities collectively herein as the “Reporting Persons” and to each as a “Reporting Person”. All capitalized terms used in this Amendment and not defined herein have the meanings ascribed to such terms in the Schedule 13D.

Item 3. Source and Amount of Funds or Other Consideration

Item 3 of the Schedule 13D is amended and supplemented by adding the following information under a new heading “ERH ROFO Notice”:

If Sprint HoldCo is the only Equityholder that exercises its rights under the ERH ROFO Notice (as defined below), the purchase price that would be paid at closing by Sprint HoldCo for 100% of the Interests (as defined below) is $100,000,063.55 (subject to adjustment for any Make Whole Payments, as discussed below), and the source of such funds would be from Sprint’s working capital.

Item 4. Purpose of Transaction.

Item 4 of the Schedule 13D is amended and supplemented by adding the following information under a new heading “ERH ROFO Notice”:

On October 17, 2012, ERH delivered an interest notice to the other Equityholders pursuant to Section 3.3 of the Equityholders’ Agreement (the “ERH ROFO Notice”). The ERH ROFO Notice provides notice to the Equityholders of ERH’s intent to transfer (i) 30,922,958 shares of Class A Common Stock (the “Class A Shares”) and (ii) 2,728,512 shares of Class B Common Stock and a corresponding number of Clearwire Communications Class B Common Interests (the “Class B Interests” and, together with the Class A Shares, the “Interests”) on the following material terms:

Pursuant to Section 3.3(b) of the Equityholders’ Agreement, each Equityholder shall have thirty (30) days from receipt of the ERH ROFO Notice to notify ERH of its election to purchase all or any portion of the Interests in accordance with the terms and conditions of the ERH ROFO Notice and the Equityholders’ Agreement.

On October 17, 2012, Sprint HoldCo delivered a response letter (“Sprint Response Letter”) to the ERH ROFO Notice notifying ERH that Sprint HoldCo elects to purchase 100% of the Interests at the purchase price set forth in the ERH ROFO Notice (or, in the event that one or more of the other Equityholders elects to purchase the Interests pursuant to a timely response notice, the maximum number of Interests that Sprint HoldCo is entitled to purchase pursuant to Section 3.3(b) of the Equityholders’ Agreement).

ERH had previously delivered an interest notice on October 13, 2012, to the other Equityholders pursuant to Section 3.3 of the Equityholders’ Agreement to which Sprint HoldCo had on that same date provided a Response Notice (as defined in the Equityholders’ Agreement) (together, the “Prior Notices”), which also covered the Interests reflected in the ERH ROFO Notice and certain additional shares owned by related parties and permitted an exercising Equityholder, under certain circumstances, to acquire the membership interests of ERH in lieu of acquiring the Interests directly. The Comcast Entities, the Intel Entities and the BHN Entities objected to certain contents of the Prior Notices and alleged that the Prior Notices were invalid. Although the Reporting Persons disagree with the merits of the objection and allegation, in the interest of avoiding a dispute over the Prior Notices, ERH and Sprint HoldCo agreed to revoke the Prior Notices, as a result of which neither has any obligations to the other thereunder, and ERH issued the ERH ROFO Notice to replace the Prior Notices (to which Sprint HoldCo responded with the Sprint Response Letter).

The foregoing summary of the ERH ROFO Notice and Sprint Response Letter is not intended to be complete and is qualified in its entirety by reference to the full text of such documents, which are filed as Exhibits 99.29 and 99.30 hereto, respectively, and are incorporated herein by reference.

Item 5. Interest in Securities of the Issuer.

Item 5(a), (b) and (c) of the Schedule 13D are hereby replaced in their entirety with the following:

(a)-(b) As of October 17, 2012, each Reporting Person may be deemed to have beneficial ownership (within the meaning of Rule 13d-3 under the Act) and shared power to vote or direct the vote of up to the amounts listed in the table below and may be deemed to constitute a “group” under Section 13(d) of the Act.

Except as set forth or incorporated herein or in the Appendices to the Schedule 13D, none of (i) the Reporting Persons and (ii) to the Sprint Entities’ knowledge, the persons set forth on Appendix A-1 and A-2 of the Schedule 13D, beneficially owns any shares of Class A Common Stock as of October 17, 2012.

In addition to the beneficial ownership of the Reporting Persons described herein, the Intel Entities, Intel Capital, Intel Cayman, Middlefield, the Comcast Entities and the BHN Entities may be deemed to be members of a “group” under Section 13(d) of the Act with the Reporting Persons by virtue of the Equityholders’ Agreement and have reported their beneficial ownership of securities of the Issuer separately, including the disclosure contained in Amendment No. 15 to Statement on Schedule 13D filed on October 5, 2012 filed by the Intel Entities, Intel Capital, Intel Cayman and Middlefield (the “Intel 13D/A”) and the disclosure contained in Amendment No. 13 to Statement on Schedule 13D filed on October 3, 2012 filed by the Comcast Entities, the BHN Entities, the Sprint Entities, the ERH Entities and the TWC Entities (as such term is defined in such Amendment) (the “Prior Joint 13D/A”). The Intel 13D/A and Prior 13D/A report beneficial ownership of 191,055,450 shares of Class A Common Stock (which consists of 88,504,132 shares of Class A Common Stock held by the Comcast Entities, 8,474,440 shares of Class B Common Stock held by the BHN Entities, 25,098,733 shares of Class A Common Stock held by Intel Capital, 3,333,333 shares of Class A Common Stock held by Intel Cayman and 65,644,812 shares of Class B Common Stock held by the Intel Entities). This beneficial ownership represents 13.0% of the Class A Common Stock held by the Comcast Entities, 1.2% of the Class A Common Stock held by the BHN Entities and 12.6% of the Class A Common Stock held by Intel Capital, Intel Cayman and the Intel Entities.

(c) Except as set forth or incorporated herein or in the Appendices to the Schedule 13D, none of (i) the Reporting Persons and (ii) to the Sprint Entities’ knowledge, the persons set forth on Appendices A-1 and A-2 of the Schedule 13D, has effected any transaction in Class A Common Stock during the 60 days prior to October 17, 2012.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer.

The information under the subheading “ERH ROFO Notice” in Item 4 of this Schedule 13D is hereby incorporated by reference.

Item 7. Material to be Filed as Exhibits.

Item 7 of the Schedule 13D is hereby amended and supplemented by adding the following at the end thereof:

SIGNATURE

After reasonable inquiry and to the best of our knowledge and belief, the undersigned certify that the information set forth in this statement is true, complete and correct.

Dated: October 17, 2012

SIGNATURE

After reasonable inquiry and to the best of our knowledge and belief, the undersigned certify that the information set forth in this statement is true, complete and correct.

Dated: October 17, 2012

SIGNATURE

After reasonable inquiry and to the best of our knowledge and belief, the undersigned certify that the information set forth in this statement is true, complete and correct.

Dated: October 17, 2012

EXHIBIT INDEX

Exhibit 99.29

Eagle River Holdings, LLC

3410 Carillon Point

Kirkland, WA 98033

October 17, 2012

Ladies and Gentleman:

Reference is made to that certain Equityholders’ Agreement, dated as of November 28, 2008, by and among Clearwire Corporation, Eagle River Holdings, LLC, a Washington limited liability company (“Eagle River”), and the other equityholders party thereto, as amended (the “Equityholders’ Agreement”). Capitalized terms not defined herein have the meanings set forth in the Equityholders’ Agreement.

Pursuant to that certain Interest Notice, dated as of October 13, 2012, Eagle River notified you of its desire to transfer certain shares of Common Stock of the Company and Units in the LLC (the “Original Interest Notice”). On October 13, 2012, pursuant to clause (iv) of the Original Interest Notice, Sprint delivered to Eagle River a Response Notice, electing to purchase 100% of the membership interests of Eagle River, in lieu of all of the offered shares of Common Stock and Units (the “Sprint Response Notice”).

Eagle River and Sprint have subsequently revoked the Original Interest Notice and the Sprint Response Notice. Accordingly, this Interest Notice shall replace and supersede the Original Interest Notice, which shall be of no force and effect as of the date hereof.

Pursuant to Section 3.3 of the Equityholders’ Agreement, Eagle River now hereby notifies you of its desire to Transfer 30,922,958 shares of Class A Common Stock of the Company (the “Class A Shares”) and 2,728,512 shares of Class B Common Stock of the Company and the corresponding Units in the LLC (the “Class B Interests” and, together with the Class A Shares, the “Interests”).

The material terms of the transaction in which Eagle River is willing to engage are as follows:

(i) Eagle River will only sell to any Non-Selling Equityholder an equal percentage of its ownership of the Class A Shares and the Class B Interests, rounded in each case to the nearest whole share or interest, as the case may be (for example, any Non-Selling Equityholder desiring to purchase 50% of the Class A Shares must also purchase 50% of the Class B Interest, taking into account the rounding).

(ii) With regard to the foregoing, the cash sales price for the bundle of each whole share of Class A Common Stock and the related fractional Class B Interest will be $2.97164 (consisting of an assigned value, only for this purpose, of $2.00 per Class A Share and $13.9835 per Class B Interest);

(iii) If at any time, and each time, after the date hereof and before October 17, 2015, any Non-Selling Equityholder that delivers a Response Notice and acquires Interests pursuant to this Interest Notice (the “Exercising Non-Selling Equityholder”) or Affiliate thereof acquires or disposes of, directly or indirectly, any Interests at a price higher than an Average Weighted Per Share Acquisition Price of $2.97164 (each a “Qualifying Subsequent Transaction”), then the following provisions of this clause (iii) will apply:

(a) The Exercising Non-Selling Equityholder will pay an additional amount in cash to Eagle River (each such payment a “Make Whole Payment”) equal to (i) the aggregate number of Interests acquired by the Exercising Non-Selling Equityholder or its Affiliate pursuant to this Notice multiplied by (ii) the excess of the Average Weighted Per Share Acquisition Price over (x) $2.97164 or (y) such higher amount established by the most recent Qualifying Subsequent Transaction (if any). If the acquisition consideration paid in a Qualifying Subsequent Transaction consists of shares of capital stock of the acquirer or its ultimate parent entity (“Acquirer Capital Stock”) or other non-cash consideration, then for these purposes each share of Acquirer Capital Stock or other such non-cash consideration will be deemed to have a value equal to the value or exchange ratio attributed to the Acquirer Capital Stock or the value attributed to such other non-cash consideration in the Qualifying Subsequent Transaction. Any such amounts payable pursuant to this clause (iii) will be paid to an account designated by Eagle River by wire transfer of immediately available funds on the fifth (5^th) Business Day following the closing of a Qualifying Subsequent Transaction. If such payment is not made when due, then interest will accrue on such amount at the rate of 10% per annum from the due date until payment is made in full, and the Exercising Non-Selling Equityholder shall be responsible for any collection costs, including attorneys’ fees and other expenses. The payment terms of this clause (iii) will be adjusted on an equitable basis to reflect any Recapitalization Event involving the Company or the LLC that occurs prior to October 17, 2015.

(b) For purposes of this Interest Notice:

“Average Weighted Per Share Acquisition Price” is the per share consideration paid in a Qualifying Subsequent Transaction calculated as follows : (1) the sum of (a) the aggregate consideration payable for Class B Common Stock and corresponding Units and (b) the aggregate consideration payable for Class A Common Stock (in each case that are acquired or disposed of by the Exercising Non-Selling Equityholder or its Affiliate in the Qualifying Subsequent Transaction) divided by (2) the number of shares of Class A Common Stock and Class B Common Stock acquired or disposed of by the Exercising Non-Selling Equityholder or its Affiliate in the Qualifying Subsequent Transaction. The fair market value of any extraordinary dividends, distributions or other amounts received by the holders in respect of their Common Stock or Units prior to or in connection with the closing of the Qualifying Subsequent Transaction shall be deemed to be consideration payable to such holders for purposes of the foregoing.

(iv) Pursuant to Section 3.3(b) of the Equityholders’ Agreement, each Non-Selling Equityholder shall have thirty (30) days from receipt of this Interest Notice (the “Notice Period”) to notify Eagle River of its election to purchase all or any portion of the Interests in accordance with the terms and conditions of this Interest Notice and the Equityholders’ Agreement.

2

If you do not intend to deliver a Response Notice, Eagle River also requests that you waive certain rights under the Equityholders’ Agreement with respect to the above-referenced proposed Transfer. By execution of this letter, the undersigned hereby waives its right of first offer pursuant to Section 3.3(b) of the Equityholders’ Agreement with respect to the above-referenced proposed Transfer. Please send the executed copy of this letter to Amit Mehta by email at amit.mehta@eriv.com.

3

Exhibit A

Sprint Nextel Corporation

2001 Edmund Halley Drive

Reston, Virginia 20191

Attention: Senior Vice President Corporate Development and Spectrum

Facsimile No.: (703) 433-4406

Sprint Nextel Corporation

6200 Sprint Parkway

Overland Park, Kansas 66251

Attention: Corporate Secretary

Facsimile No.: (913) 523-9797

With a copy to:

King & Spalding LLP

1180 Peachtree Street, N.E.

Atlanta, Georgia 30309

Attention: Michael J. Egan

Facsimile No.: (404) 572-5100

Comcast Corporation

One Comcast Center

1701 John F. Kennedy Boulevard

Philadelphia, Pennsylvania 19103

Attention: Chief Financial Officer

Facsimile No.: (215) 286-1240

Comcast Corporation

One Comcast Center

1701 John F. Kennedy Boulevard

Philadelphia, Pennsylvania 19103

Attention: General Counsel

Facsimile No.: (215) 286-7794

With a copy to:

Davis Polk & Wardwell

450 Lexington A venue

New York, New York 10017

Attention: David L. Caplan

Facsimile No.: (212) 450-3800

5

Bright House Networks, LLC

c/o Advance/Newhouse Partnership

5000 Carnpuswood Drive

East Syracuse, NY 13057

Attn: Leo Cloutier

Facsimile No.: (315) 438-4643

With a copy to:

Sabin, Bermant & Gould LLP

Four Times Square

New York, NY 10036

Attn: Arthur J. Steinhauer, Esq.

Facsimile No.: (212) 381-7218

Intel Corporation

2200 Mission College Blvd., MS RN6-65

Santa Clara, California 95054-1549

Attention: President, Intel Capital

Facsimile No.: (408) 765-8871

Intel Corporation

2200 Mission College Blvd., MS RN6-59

Santa Clara, California 95054-1549

Attention: Intel Capital Portfolio Manager

Facsimile No.: (408) 653-6796

Intel Corporation

2200 Mission College Blvd., MS RN4-151

Santa Clara, California 95054-1549

Attention: Intel Capital Group General Counsel

Facsimile No.: (408) 653-9098

Intel Corporation

2200 Mission College Blvd., MS RNS-125

Santa Clara, California 95054-1549

Attention: Director, U.S. Tax and Trade

Facsimile No.: (408) 765-1733

Gibson, Dunn & Crutcher LLP

1881 Page Mill Road

Palo Alto, California 94304

Attention: Gregory T. Davidson

Facsimile No.: (650) 849-5050

6

With a copy to:

Gibson, Dunn & Crutcher LLP

333 South Grand Avenue

Los Angeles, California 90071-3197

Attention: Paul S. Issler

Facsimile No.: (213) 229-6763

7

Exhibit 99.30

SPRINT HOLDCO, LLC

6200 Sprint Parkway

Overland Park, Kansas 66251

October 17, 2012

Ladies and Gentleman:

Reference is made to: (i) that certain Equityholders’ Agreement, dated as of November 28, 2008, by and among Clearwire Corporation, a Delaware corporation (the “Company”), Sprint HoldCo, LLC, a Delaware limited liability company (“Sprint HoldCo”), and the other equityholders party thereto, as amended (the “Equityholders’ Agreement”); and (ii) that certain notice delivered by Eagle River by facsimile to the parties listed on Exhibit A thereto on October 17, 2012 (the “Interest Notice”) regarding the intended Transfer of 30,922,958 shares of Class A Common Stock of the Company (the “Class A Shares”) and 2,728,512 shares of Class B Common Stock of the Company and the corresponding Units in the LLC (the “Class B Interests” and, together with the Class A Shares, the “Interests”). Capitalized terms not defined herein have the meanings set forth in the Equityholders’ Agreement.

Pursuant to Section 3.3 of the Equityholders’ Agreement, and subject to the terms and conditions set forth in the Equityholders’ Agreement, Sprint HoldCo hereby provides notice to Eagle River of its intention to purchase all of the Interests (or, in the event that one or more of the other Non-Selling Equityholders elects to purchase Interests pursuant to a Response Notice, the maximum number of Interests that Sprint HoldCo is entitled to purchase pursuant to Section 3.3(b) of the Equityholders’ Agreement) at the purchase price set forth in the Interest Notice and on the other terms and conditions set forth in the Interest Notice.

For the avoidance of doubt, Sprint HoldCo reserves all of their other rights under the Equityholders’ Agreement.

* * * * * * *

Exhibit 99.31

Joint Filing Agreement

The undersigned hereby agrees that they are filing this Amendment No. 14 to Schedule 13D jointly pursuant to Rule 13d-1(k)(1) of the Securities Exchange Act of 1934, as amended, with respect to the shares of common stock of Clearwire Corporation. The undersigned further agree and acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning it contained herein, but shall not be responsible for completeness and accuracy of the information concerning the other, except to the extent that it knows or has reason to believe that such information is inaccurate.

Dated: October 17, 2012