<PAGE>   1

                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                 FORM 10-K/A

                               Amendment No. 2 to
                  Annual Report Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934
                   For the fiscal year ended December 31, 1996

                         COMMISSION FILE NO. 0-24308


                 COHERENT COMMUNICATIONS SYSTEMS CORPORATION
            (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

          DELAWARE                                 11-2162982
(State or other jurisdiction of           (I.R.S. Employer Identification No.)
incorporation or organization)

                           44084 RIVERSIDE PARKWAY
                          LANSDOWNE BUSINESS CENTER
                            LEESBURG, VIRGINIA 22075
                                (703) 729-6400

              (Address of principal executive offices) (Zip Code)
              (Registrant's telephone number, including area code)

Securities registered pursuant to section 12(b) of the Act:

Title of each class                                       Name of each
                                                  exchange on which registered

      None                                               Not applicable

Securities registered pursuant to section 12(g) of the Act:

                     COMMON STOCK, PAR VALUE $.01 PER SHARE

   Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to
such filing requirements for the past 90 days.  [X]

   Indicate by check mark if disclosure of delinquent filers pursuant to Item
495 of Regulation S-K is not contained herein, and will not be contained, to
the best of the registrant's knowledge, in definitive proxy or information
statements incorporated by reference in Part III of this Form 10-K or any
amendment of this Form 10-K.  [X]

   The aggregate market value of voting stock held by nonaffiliates of the
registrant as of March 13, 1997, was approximately $153,044,650 based on the
sale price of the Common Stock on March 13, 1997, of $16.75 as reported by the
NASDAQ National Market System. As of March 13, 1997, the registrant had
outstanding 15,146,522 shares of its Common Stock, par value $.01 per share.

DOCUMENTS INCORPORATED BY REFERENCE

   Portions of the Proxy Statement for the Annual Meeting of Stockholders to be
held on May 15, 1997 are incorporated herein by reference in Part III, Items 10,
11, 12 and 13.
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                                   PART IV

ITEM  14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K

      (a) The following documents are filed as part of this Annual Report on
          Form 10-K:

      1. Consolidated Financial Statements:
         The consolidated financial statements filed as a part of this report
         are listed in the "Index to Consolidated Financial Statements and
         Financial Statement Schedule" at Item 8.

      2. Consolidated Financial Statement Schedule:
         The consolidated financial statement schedule filed as part of this
         report is listed in the "Index to Consolidated Financial Statements and
         Financial Statement Schedule" at Item 8.

         Schedules other than those listed on the accompanying Index to
         Consolidated Financial Statements and Financial Statement Schedule are
         omitted for the reason that they are either not required, not
         applicable, or the required information is included in the consolidated
         financial statements or notes thereto.

      (b)   REPORTS ON FORM 8-K     None.

      (c)   Exhibits:

         The following is a list of exhibits required by Item 601 of Regulation
         S-K filed as part of this report. Where so indicated by footnote,
         exhibits which were previously filed are incorporated by reference.
         Exhibits incorporated by reference, the location of the exhibit in the
         previous filing is indicated in parentheses. All other exhibits are
         being filed with this report.

   Exhibit No.                               Description
   -----------                               -----------
      
       3(i)   -  Certificate of Incorporation of the Company, as amended by a
                 Certificate of Amendment.(3) (Exhibit 3.1(i))

      3(ii)   -  By-laws of the Company as amended.(5)(Exhibit 3(ii))

        4.1   -  Specimen stock certificate representing the Common Stock.(3)
                 (Exhibit 4.1)

       10.1   -  Administrative Services Agreement dated as of December 1, 1993,
                 between the Company and Safeguard Scientifics, Inc.(3)
                 (Exhibit 10.1)

       10.2   -  Asset Purchase Agreement dated as of March 18, 1987 between
                 COMSAT Telesystems, Inc.  and the Company.(1)(Exhibit 10.2)

      *10.3   -  1982 Stock Option Plan.(1)(Exhibit 10.3)

      *10.4   -  1993 Equity Compensation Plan, as amended and
                 restated.(6)(Exhibit 10.4)

    *10.4.1   -  Stock Ownership Plan.(5)(Exhibit 10.4.1)

     10.4.2      Compensation Plan for Outside Directors.

      *10.5   -  Form of Non-Qualified Stock Option Agreement of the Company for
                 Employees.(2)(Exhibit 10.5)

      *10.6   -  Form of Non-Qualified Stock Option Agreement of the Company for
                 Directors.(2)(Exhibit 10.6)

      *10.7   -  Form of Incentive Stock Option Agreement of the Company for
                 Employees.(2)(Exhibit 10.7)

       10.8   -  Lease dated as of February 1, 1980, as amended, between LE-AX
                 Corp. and the Company, for the property at 60 Commerce Drive,
                 Hauppauge, New York.(1)(Exhibit 10.8)


                                       2
<PAGE>   3
ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K

      (c)   Exhibits (continued):

      10.9.1 - Lease dated as of July 31, 1992 between Linpro Lansdowne Two
               Limited Partnership and the Company, for the property at 44084
               Riverside Parkway, Leesburg, Virginia.(1)(Exhibit 10.9.1)

      10.9.2 - Sublease dated as of August 1993 between G.D.  Searle & Co.
               and the Company, for the property at 44084 Riverside Parkway,
               Leesburg, Virginia.(1)(Exhibit 10.9.2)

      10.9.3   Lease dated August 9, 1996 by and between Opus East,, L.L.C.,
               Landlord, and the Company for the premises located in Loudon
               County, Virginia known as University Center.(6)(Exhibit 10.9.3)

       10.10 - Lease dated as of October 15, 1990 between Kibswell Holdings
               Limited and the Company, for the property at Unit B The Quadrant,
               Barton Lane, Abingdon, England.(1)(Exchange 10.10)

       10.11 - Tax Agreement dated January 1, 1983 between Safeguard
               Scientifics, Inc.  and the Company.(1)(Exhibit 10.11)

      *10.12 - Severance and Non-Competition Agreement dated as of February
               10, 1994 between Daniel McGinnis and the Company.(1)(Exhibit
               10.12)

       10.13 - Form of Demand Promissory Note of Safeguard Scientifics, Inc.,
               dated April 2, 1993, payable to the Company, as amended by letter
               Agreement dated January 12, 1994.(1)(Exhibit 10.13)

       10.14 - Form of Promissory Note of the Company payable to Safeguard
               Scientifics, Inc. with respect to the redemption of redeemable
               convertible preferred stock.(3)(Exhibit 10.14)

       10.15 - Supply and License Agreement dated February 7, 1992, between
               the Company and TRT Telecommunications Radioelectriques et
               Telephoniques.(1)(Exhibit 10.15)

       10.16 - International Distribution Agreement dated as of January 2,
               1992 between the Company and Cohpac Communications Systems Pty
               Limited.(1)(Exhibit 10.16)

       10.17 - North America Value Added Reseller Agreement dated as of
               December 7, 1992 between the Company and Wandel & Goltermann
               Inc.(1)(Exhibit 10.17)

      *10.18 - Management Incentive Compensation Plan, as adopted by the
               Company.(2)(Exhibit 10.18)

       10.19 - License Agreement, effective as of June 1, 1994, between the
               Company and Systems Technology Associates, Inc. (3)(Exhibit
               10.19)

       10.20 - Value Added Reseller Agreement dated December 31, 1992 as
               amended June 13, 1995 between the Company and Nokia
               Telecommunications Oy.(5)(Exhibit 10.21)**

       10.21   Memorandum of Understanding dated February 27, 1997 between the
               Company and Nokia Telecommunications Oy.**

        11.0 - Computation of net income per share.(6)(Exhibit XI)


                                       3
<PAGE>   4
ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K

      (c)   Exhibits (continued):

        21.0 - Subsidiaries of registrant.(6)(Exhibit 21.0) 

        23.0 - Consent of KPMG Peat Marwick LLP.(6)(Exhibit 23.0) 

        27.0 - Financial Data Schedule.(6)(Exhibit 27.0)

----------------

(1)Filed on March 31, 1994 as an exhibit to the Company's Registration
   Statement on Form S-1 (No.33-77160) and incorporated by reference.

(2)Filed on May 24, 1994 as an exhibit to the Company's Registration Statement
   on Form S-1 Amendment #1 (No.33-77160) and incorporated by reference.

(3)Filed on June 10, 1994 as an exhibit to the Company's Registration Statement
   on Form S-1 Amendment #2 (No.33-77160) and incorporated by reference.

(4)Filed as an exhibit to the Company's Annual Report on Form 10-K for the year
   ended December 31, 1994 and incorporated by reference.

(5)Filed as an exhibit to the Company's Annual Report on Form 10-K for the year
   ended December 31, 1995 and incorporated by reference.

(6)Filed as an exhibit to the Company's Annual Report on Form 10-K for the year
   ended December 31, 1996 and incorporated by reference.                      

*  Management contract or compensatory plan or arrangement.

** Confidential portions of the exhibit have been omitted and filed separately
   with the Securities and Exchange Commission pursuant to a request for
   confidential treatment.


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   SIGNATURES

      Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this to be signed on its
behalf by the undersigned, thereunto duly authorized.


                               COHERENT COMMUNICATIONS SYSTEMS CORPORATION


                               By:  /s/ Daniel L. McGinnis                    
                                    ---------------------------
                                    Daniel L. McGinnis
                                    Chief Executive Officer


                                    Date: December 10, 1998
     
 
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                                  EXHIBIT INDEX

The following is a list of exhibits required by Item 601 of Regulation S-K filed
as part of this Report. Where so indicated by footnote, exhibits which were
previously filed are incorporated by reference. For exhibits incorporated by
reference, the location of the exhibit in the previous filing is indicated in
parentheses. The page numbers listed refer to the page numbers where such
exhibits are located using the sequential numbering system specified by Rule
0-3.


  Exhibit No.                        Description
  -----------                        -----------
    
       3(i) - Certificate of Incorporation of the Company, as amended by a
              Certificate of Amendment.(3) (Exhibit 3.1(i))
      3(ii) - By-laws of the Company as amended.

        4.1 - Specimen stock certificate representing the Common
              Stock.(3)(Exhibit 4.1)

       10.1 - Administrative Services Agreement dated as of December 1, 1993,
              between the Company and Safeguard Scientifics, Inc.(3)(Exhibit
              10.1)

       10.2 - Asset Purchase Agreement dated as of March 18, 1987 between COMSAT
              Telesystems, Inc.  and the Company.(1)(Exhibit 10.2)

      *10.3 - 1982 Stock Option Plan.(1)(Exhibit 10.3) 
 
      *10.4 - 1993 Equity Compensation Plan, as amended and
              restated.(6)(Exhibit 10.4)

    *10.4.1   Stock Ownership Plan.(5)(Exhibit 10.4.1)

     10.4.2   Compensation Plan for Outside Directors.

      *10.5 - Form of Non-Qualified Stock Option Agreement of the Company for
              Employees.(2)(Exhibit 10.5)

      *10.6 - Form of Non-Qualified Stock Option Agreement of the Company for
              Directors.(2)(Exhibit 10.6)

      *10.7 - Form of Incentive Stock Option Agreement of the Company for
              Employees.(2)(Exhibit 10.7)

       10.8 - Lease dated as of February 1, 1980, as amended, between LE-AX
              Corp. and the Company, for the property at 60 Commerce Drive,
              Hauppauge, New York.(1)(Exhibit 10.8)

     10.9.1 - Lease dated as of July 31, 1992 between Linpro Lansdowne Two
              Limited Partnership and the Company, for the property at 44084
              Riverside Parkway, Leesburg, Virginia.(1)(Exhibit 10.9.1)

     10.9.2 - Sublease dated as of August 1993 between G.D.  Searle &
              Co.  and the Company, for the property at 44084 Riverside
              Parkway, Leesburg, Virginia.(1)(Exhibit 10.9.2)

     10.9.3   Lease dated August 9, 1996 by and between Opus East,, L.L.C.,
              Landlord, and the Company, for the premises located in Loudon
              County, Virginia known as University Center.(6)(Exhibit 10.9.3)

      10.10 - Lease dated as of October 15, 1990 between Kibswell Holdings
              Limited and the Company, for the property at Unit B The Quadrant,
              Barton Lane, Abingdon, England.(1)(Exchange 10.10)

      10.11 - Tax Agreement dated January 1, 1983 between Safeguard
              Scientifics, Inc. and the Company.(1)(Exhibit 10.11)

     *10.12 - Severance and Non-Competition Agreement dated as of February 10,
              1994 between Daniel McGinnis and the Company.(1)(Exhibit 10.12)


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<PAGE>   7
      10.13 - Form of Demand Promissory Note of Safeguard Scientifics, Inc.,
              dated April 2, 1993, payable to the Company, as amended by letter
              Agreement dated January 12, 1994.(1)(Exhibit 10.13)

      10.14 - Form of Promissory Note of the Company payable to Safeguard
              Scientifics, Inc. with respect to the redemption of redeemable
              convertible preferred stock.(3)(Exhibit 10.14)

      10.15 - Supply and License Agreement dated February 7, 1992, between the
              Company and TRT Telecommunications Radioelectriques et
              Telephoniques.(1)(Exhibit 10.15)

      10.16 - International Distribution Agreement dated as of January 2, 1992
              between the Company and Cohpac Communications Systems Pty
              Limited.(1)(Exhibit 10.16)

      10.17 - North America Value Added Reseller Agreement dated as of
              December 7, 1992 between the Company and Wandel & Goltermann
              Inc.(1)(Exhibit 10.17)

     *10.18 - Management Incentive Compensation Plan, as adopted by the
              Company.(2)(Exhibit 10.18)

      10.19 - License Agreement, effective as of June 1, 1994, between the
              Company and Systems Technology Associates, Inc. (3)(Exhibit 10.19)

      10.20 - Value Added Reseller Agreement dated December 31, 1992 as amended
              June 13, 1995 between the Company and Nokia Telecommunications Oy.
              (5)(Exhibit 10.21)**

      10.21 - Memorandum of Understanding dated February 27, 1997 between the
              Company and Nokia Telecommunications Oy.**

      11.0  - Computation of net income per share.(6)(Exhibit XI)

      21.0  - Subsidiaries of registrant.(6)(Exhibit 21.0)

      23.0  - Consent of KPMG Peat Marwick LLP.(6)(Exhibit 23.0)

      27.0  - Financial Data Schedule.(6)(Exhibit 27.0)

----------------

(1)Filed on March 31, 1994 as an exhibit to the Company's Registration
   Statement on Form S-1 (No.33-77160) and incorporated by reference.

(2)Filed on May 24, 1994 as an exhibit to the Company's Registration Statement
   on Form S-1 Amendment #1 (No.33-77160) and incorporated by reference.

(3)Filed on June 10, 1994 as an exhibit to the Company's Registration Statement
   on Form S-1 Amendment #2 (No.33-77160) and incorporated by reference.

(4)Filed as an exhibit to the Company's Annual Report on Form 10-K for the year
   ended December 31, 1994 and incorporated by reference.

(5)Filed as an exhibit to the Company's Annual Report on Form 10-K for the year
   ended December 31, 1995 and incorporated by reference.

(6)Filed as an exhibit to the Company's Annual Report on Form 10-K for the year
   ended December 31, 1996 and incorporated by reference.                      

*  Management contract or compensatory plan or arrangement.

** Confidential portions of the exhibit have been omitted and filed separately
   with the Securities and Exchange Commission pursuant to a request for
   confidential treatment.





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