<PAGE>
                                                                    Exhibit 4.31

THE WARRANTS REPRESENTED BY THIS CERTIFICATE WILL BE VOID AND OF NO VALUE UNLESS
EXERCISED BY 4:30 P.M. (VANCOUVER TIME) ON OR BEFORE SEPTEMBER 23, 2005.

WITHOUT THE PRIOR WRITTEN APPROVAL OF THE TORONTO STOCK EXCHANGE AND COMPLIANCE
WITH ALL APPLICABLE SECURITIES LEGISLATION, THE SECURITIES REPRESENTED BY THIS
CERTIFICATE AND THE COMMON SHARES ISSUABLE UPON THE EXERCISE HEREOF MAY NOT BE
SOLD, TRANSFERRED, HYPOTHECATED OR OTHERWISE TRADED ON OR THROUGH THE FACILITIES
OF THE TORONTO STOCK EXCHANGE OR OTHERWISE IN CANADA OR TO OR FOR THE BENEFIT OF
A CANADIAN RESIDENT UNTIL JULY 24, 2004.

UNLESS PERMITTED UNDER SECURITIES LEGISLATION, THE HOLDER OF THE SECURITIES
SHALL NOT TRADE THE SECURITIES BEFORE JULY 24, 2004.

THE SECURITIES COVERED HEREBY HAVE NOT BEEN REGISTERED UNDER THE U.S. SECURITIES
ACT OF 1933 (THE "1933 ACT"), AND MAY NOT BE OFFERED OR SOLD WITHIN THE UNITED
STATES OR TO, OR FOR THE ACCOUNT OR BENEFIT OF, U.S. PERSONS (I) AS PART OF
THEIR DISTRIBUTION AT ANY TIME OR (II) OTHERWISE UNTIL 40 DAYS AFTER THE LATER
OF THE COMMENCEMENT OF THE OFFERING AND CLOSING DATE, EXCEPT IN EITHER CASE IN
ACCORDANCE WITH REGULATION S UNDER THE 1933 ACT. TERMS USED HEREIN HAVE THE
MEANING GIVEN TO THEM IN REGULATION S.


<PAGE>

                                      -2-

                               WARRANT CERTIFICATE

                         SPECTRUM SIGNAL PROCESSING INC.
                     (Incorporated under the laws of Canada)


WARRANT                                _____ WARRANTS, each entitling the holder
CERTIFICATE NO. ___                    to acquire, subject to adjustment and
                                       without payment of any additional
                                       consideration, one Common Share at a
                                       price of Cdn.$1.50 per share for each
                                       whole Offered Warrant represented hereby.

         THIS IS TO CERTIFY THAT __________________________________________

(hereinafter referred to as the "holder") is entitled to acquire in the manner
and subject to the restrictions and adjustments set forth herein, at any time
and from time to time until 4:30 p.m. (Vancouver time) (the "Expiry Time") on
September 23, 2005 (the "Expiry Date"), one fully paid and non-assessable common
share ("Common Share") without nominal or par value of SPECTRUM SIGNAL
PROCESSING INC. (the "Corporation"), as such shares were constituted on March
23, 2004 at an exercise price of Cdn.$1.50, subject to adjustment as described
below (the "Exercise Price") for each Offered Warrant represented hereby.

         The Offered Warrants represented by this certificate are issued under
and pursuant to an Offered Warrant Indenture (hereinafter referred to as the
"Indenture") made as of March 23, 2004 between the Corporation and Computershare
Trust Company of Canada (the "Trustee"). Reference is made to the Indenture and
any instruments supplemental thereto for a full description of the rights of the
holders of the Offered Warrants and the terms and conditions upon which the
Offered Warrants are, or are to be, issued and held, with the same effect as if
the provisions of the Indenture and all instruments supplemental thereto were
herein set forth. By acceptance hereof, the holder assents to all provisions of
the Indenture. In the event of a conflict between the provisions of this Offered
Warrant Certificate and the Indenture, the provisions of the Indenture shall
govern. Capitalized terms used in the Indenture have the meaning herein as
therein, unless otherwise defined.

         The right to acquire Common Shares may be exercised by the holder
within the time set forth above by:

  (a)    duly completing and executing the Offered Warrant Exercise Form
         attached hereto; and

  (b)    surrendering this Offered Warrant Certificate to the Trustee together
         with a certified cheque, bank draft or money order, in lawful money of
         Canada payable to or to the order of the Corporation at par at the
         principal offices of the Trustee in the cities of Calgary or Toronto or
         Vancouver for the Exercise Price for the Common Shares subscribed for.

<PAGE>

                                      -3-

         These Offered Warrants shall be deemed to be surrendered only upon
personal delivery hereof or, if sent by mail or other means of transmission,
upon actual receipt thereof by the Trustee at either office referred to above.

         Upon surrender of these Offered Warrants, the person or persons in
whose name or names the Common Shares issuable upon exercise of the Offered
Warrants are to be issued shall be deemed for all purposes (except as provided
in the Indenture) to be the holder or holders of record of such Common Shares
and the Corporation has covenanted that it will (subject to the provisions of
the Indenture) cause a certificate or certificates representing such Common
Shares to be delivered or mailed to the person or persons at the address or
addresses specified in the Offered Warrant Exercise Form within three (3)
Business Days of the receipt of this Offered Warrant Certificate, the Exercise
Price and the Offered Warrant Exercise Form duly completed.

         The registered holder of these Offered Warrants may acquire any lesser
number of Common Shares than the number of Common Shares which may be acquired
for the Offered Warrants represented by this Offered Warrant Certificate. In
such event, the holder shall be entitled to receive a new Offered Warrant
Certificate for the balance of the Common Shares which may be acquired. Any
fractional entitlements will be rounded down to the nearest whole number.

         These Offered Warrants and the Common Shares issuable upon exercise of
the Offered Warrants have not been and will not be registered under the United
States Securities Act of 1933, as amended (the "U.S. Securities Act"). These
Offered Warrants may be offered, sold, pledged or otherwise transferred only (A)
to the Corporation, (B) in a transaction outside the United States in compliance
with Rule 904 of Regulation S under the U.S. Securities Act, or (C) in a
transaction exempt from the registration requirements under the U.S. Securities
Act and any applicable state securities laws. In connection with any transfer
pursuant to the foregoing clause (C), there must be furnished to the Corporation
a written opinion of counsel reasonably acceptable to the Corporation to the
effect that such transfer is exempt from the regulation requirements of all
applicable United States federal and state securities laws. Any person in the
United States or "U.S. person" as defined in Regulation S under the U.S.
Securities Act, that transfers Offered Warrants outside the United States in
accordance with Rule 904 of Regulation S must execute a Declaration in the form
attached hereto as Exhibit A to this Offered Warrant Certificate. A Offered
Warrantholder that either (i) is at the time of exercise of these Offered
Warrants in the United States, (ii) is a "U.S. person" as defined in Regulation
S under the U.S. Securities Act, or (iii) that executes or delivers the Offered
Warrant Exercise Form in the United States, must sign and deliver a letter in
the form attached hereto as Exhibit B to the Offered Warrant Certificate.


<PAGE>


                                      -4-

         In the event of any alteration of the Common Shares, including any
subdivision, consolidation or reclassification, and in the event of any form of
reorganization of the Corporation, including any amalgamation, merger or
arrangement, an adjustment shall be made to the terms of the Offered Warrants
such that the holders of Offered Warrants shall, upon exercise of the Offered
Warrants following the occurrence of any of those events, be entitled to receive
the same number and kind of securities that they would have been entitled to
receive had they exercised their Offered Warrants immediately prior to the
occurrence of those events, provided that no fractional shares will be issued.
The Indenture also provides that the exercise price per Common Share is subject
to adjustment in certain events.

         The registered holder of this Offered Warrant Certificate may, at any
time prior to the Expiry Time, upon surrender hereof to the Trustee at its
principal offices in the cities of Calgary or Toronto or Vancouver, exchange
this Offered Warrant Certificate for other Offered Warrant Certificates
entitling the holder to acquire, in the aggregate, the same number of Common
Shares as may be acquired under this Offered Warrant Certificate.

         The holding of the Offered Warrants evidenced by this Offered Warrant
Certificate shall not constitute the holder hereof a shareholder of the
Corporation or entitle the holder to any right or interest in respect thereof
except as expressly provided in the Indenture and in this Offered Warrant
Certificate.

         The Indenture provides that all holders of Offered Warrants shall be
bound by any resolution passed at a meeting of the holders held in accordance
with the provisions of the Indenture and resolutions signed by the holders of
Offered Warrants entitled to acquire a specified majority of the Common Shares
which may be acquired pursuant to all then outstanding Offered Warrants.

         The Offered Warrants evidenced by this Offered Warrant Certificate may
be transferred on the register kept at the offices of the Trustee by the
registered holder hereof or its legal representatives or its attorney duly
appointed by an instrument in writing in form and execution satisfactory to the
Trustee, upon compliance with the conditions prescribed in the Indenture and
upon compliance with such reasonable requirements as the Trustee may prescribe.

         This Offered Warrant Certificate shall not be valid for any purpose
whatever unless and until it has been certified by or on behalf of the Trustee.

         Time shall be of the essence hereof.

         IN WITNESS WHEREOF the Corporation has caused this Offered Warrant
Certificate to be signed by its duly authorized officer as of March 23, 2004.


                                                 SPECTRUM SIGNAL PROCESSING INC.


                                                 Per:  /s/ Pascal Spothelfer
                                                       -------------------------



<PAGE>

                                      -5-

Certified by:
COMPUTERSHARE TRUST COMPANY OF CANADA
Trustee

By: /s/ Nicole Clement
    ------------------------------------------






<PAGE>



                              TRANSFER OF WARRANTS

         FOR VALUE RECEIVED, the undersigned hereby sells, assigns and transfers
to ___________________________________________ [NAME AND ADDRESS OF TRANSFEREE],
___________________________________________ [NUMBER OF OFFERED WARRANTS] Offered
Warrants of SPECTRUM SIGNAL PROCESSING INC. registered in the name of the
undersigned on the records of Computershare Trust Company of Canada represented
by the Offered Warrant Certificate attached and irrevocably appoints
Computershare Trust Company of Canada the attorney of the undersigned to
transfer the said securities on the books or register with full power of
substitution.

         The undersigned hereby certifies the following (CHECK ONE AND ONLY ONE
OF THE FOLLOWING BOXES THAT IS APPLICABLE):

         A. [ ] that the transfer of these securities is not being made to, and
the offer of these securities was not made to, a person in the United States or
a U.S. Person, as such terms are defined in Regulation S under the United States
Securities Act of 1933, as amended (the "U.S. Securities Act")

         B. [ ] that the transfer of these securities is being made in
accordance with, and pursuant to, an exemption from registration under the U.S.
Securities Act and any applicable state securities laws.

         DATED the ________ day of ______________ , 200___




_______________________________________   ______________________________________
Signature Guaranteed                      (Signature of Offered Warrantholder)


                                          ______________________________________
                                          Name of Offered Warrantholder


                                          ______________________________________
                                          Address of Offered Warrantholder


Instructions:

1.       Signature of the Offered Warrantholder must be the signature of the
         person appearing on the face of this Offered Warrant Certificate.

2.       If the Transfer Form is signed by a trustee, executor, administrator,
         curator, guardian, attorney, officer of a corporation or any person
         acting in a fiduciary or representative capacity, the certificate must
         be accompanied by evidence of authority to sign satisfactory to the
         Trustee and the Corporation.

3.       The signature on the Transfer Form must be guaranteed by a Schedule A
         major chartered bank/trust company, or a member of an acceptable
         Medallion Guarantee Program. The guarantor must affix a stamp bearing
         the actual words "Signature Guaranteed". Please note signature
         guarantees are not accepted from Treasury Branches or Credit Unions


<PAGE>

                                      -2-

         unless they are members of the Stamp Medallion Program. Please note
         that in the United States, signature guarantees must be done by members
         of the Medallion Signature Guarantee Program only.

4.       If the Offered Warrant Certificate contains a restrictive legend
         relating to the U.S. Securities Act and Box A above is checked, this
         transfer form must be accompanied by a completed and executed
         declaration for removal of legend in the form attached as Exhibit A to
         the Offered Warrant Certificate.

5.       If Box B above is checked, Spectrum Signal Processing Inc. must be
         provided a written opinion of legal counsel reasonably satisfactory to
         Spectrum Signal Processing Inc. to the effect that the proposed
         transfer may be effected without registration under the U.S. Securities
         Act and any applicable state securities laws. In connection with any
         such proposed transfer of the Offered Warrants, Spectrum Signal
         Processing Inc. may request such further information as may be
         necessary to determine whether such transfers are being made: (i) to
         "accredited investors" as such terms is defined in Regulation D under
         the U.S. Securities Act; (ii) in accordance with, and pursuant to, an
         exemption from registration under the U.S. Securities Act and any
         applicable state securities laws and (iii) otherwise in compliance with
         applicable securities laws.





<PAGE>



                                  EXERCISE FORM


TO:                     SPECTRUM SIGNAL PROCESSING INC. (The "Corporation")
AND TO:                 Computershare Trust Company of Canada (The "Trustee")
DELIVER TO:             100 University Avenue
                        8th Floor
                        Toronto, Ontario  M5J 2Y1
                        or
                        Suite 710, Western Gas Tower 530 - 8th Avenue S.W.
                        Calgary, Alberta T2P 3S8
                        or
                        510 Burrard Street
                        2nd Floor
                        Vancouver, British Columbia V6C 3B9
                        or
                        1500 University Street
                        7th Floor
                        Montreal Quebec H3A 3S8

         The undersigned hereby exercises the right to acquire Common Shares of
SPECTRUM SIGNAL PROCESSING INC. as constituted on March 23, 2004 (or such number
of other securities or property to which such Offered Warrants entitle the
undersigned in lieu thereof or in addition thereto under the provisions of the
Indenture referred to in the accompanying Offered Warrant Certificate) in
accordance with and subject to the provisions of such Indenture.

   The Common Shares (or other securities or property) are to be issued as
follows:

   Name: _______________________________________________________________________
         (print clearly)

   Address in full: ____________________________________________________________

  ______________________________________________________________________________

   Social Insurance Number: ____________________________________________________

   Number of Common Shares: ____________________________________________________

   Note: If further nominees intended, please attach (and initial) schedule
   giving these particulars.

   The undersigned holder hereby represents and certifies as follows (CHECK ONE
   AND ONLY ONE OF THE FOLLOWING BOXES THAT IS APPLICABLE):

   A. [ ] The undersigned holder (i) at the time of exercise of these Offered
   Warrants is not in the United States; (ii) is not a "U.S. person" as defined
   in Regulation S under the United States Securities Act of 1933, as amended
   (the "U.S. Securities Act") and is not exercising these Offered Warrants on
   behalf of a "U.S. person," or a

<PAGE>

                                      -2-

   person in the United States, and (iii) did not execute or deliver this
   Offered Warrant Exercise Form in the United States.

   B. [ ] The undersigned holder is either: (A) an Original U.S. Purchaser, as
   such term is defined in the Indenture, and each representation, warranty and
   covenant made by the undersigned in the Subscription Agreement entered into
   by and between the undersigned and the Corporation, pursuant to which the
   undersigned purchased Units is true and correct as of the date hereof, or (B)
   a U.S. person, or a person in the United States, that has acquired these
   Offered Warrants in a transaction exempt from registration under the U.S.
   Securities Act where such transfer was in compliance with the Indenture and
   any applicable state securities laws and has signed and delivered a letter in
   the form attached hereto as Exhibit B to the Offered Warrant Certificate.


   Dated this _______ day of ______________, 200 __





----------------------------------    ------------------------------------------
Signature Guaranteed                  (Signature of Offered Warrantholder)


                                      ------------------------------------------
                                      Print full name


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


                                      ------------------------------------------
                                      Print full address


Instructions:

1.       The registered holder may exercise its right to receive Common Shares
         by completing this form and surrendering this form and the Offered
         Warrant Certificate representing the Offered Warrants being exercised
         together with the exercise price to Computershare Trust Company of
         Canada at its principal offices at 100 University Avenue, 8th Floor,
         Toronto, Ontario M5J 2Y1, Suite 710 Western Gas Tower, 530 - 8th Avenue
         S.W., Calgary, Alberta, T2P 3S8, 510 Burrard Street, 2nd Floor,
         Vancouver, British Columbia, V6C 3B9 or 1500 University Street, 7th
         Floor, Montreal Quebec H3A 3S8 Certificates for Common Shares will be
         delivered or mailed within three (3) business days after the exercise
         of the Offered Warrants.

2.       If the Offered Warrant Exercise Form indicates that Common Shares are
         to be issued to a person or persons other than the registered holder of
         the Certificate the signature of such holder must be guaranteed by a
         Schedule A major chartered bank/trust company, or a member of an
         acceptable Medallion Guarantee Program. The guarantor must affix a
         stamp bearing the actual words "Signature Guaranteed". Please note
         signature guarantees are not accepted from Treasury Branches or Credit
         Unions unless they are members of the Stamp Medallion Program. Please
         note that in the United States, signature guarantees must be done by
         members of the Medallion Signature Guarantee Program only.

3.       If the Offered Warrant Exercise Form is signed by a trustee, executor,
         administrator, curator, guardian, attorney, officer of a corporation or
         any person acting in a fiduciary or representative capacity, the
         certificate must be accompanied by evidence of authority to sign
         satisfactory to the Trustee and the Corporation.

4.       Certificates representing Common Shares will not be registered or
         delivered to an address in the United States unless Box B above is
         checked.

<PAGE>

                                      -3-

5.       If Box B above is checked, the certificate representing the Common
         Shares will bear a legend in the form set forth in the Indenture
         restricting transfer without registration under the U.S. Securities Act
         and applicable state securities laws unless an exemption from
         registration is available.


<PAGE>


                                    EXHIBIT A

                    FORM OF DECLARATION FOR REMOVAL OF LEGEND

TO:      COMPUTERSHARE TRUST COMPANY OF CANADA
         as registrar and transfer agent for Common Shares and Offered Warrants
         of SPECTRUM SIGNAL PROCESSING INC.

The undersigned (a) acknowledges that the sale of the securities of SPECTRUM
SIGNAL PROCESSING INC. (the "Corporation") to which this declaration relates is
being made in reliance on Rule 904 of Regulation S under the United States
Securities Act of 1933, as amended (the "1933 Act") and (b) certifies that (1)
the undersigned is not an affiliate of the Corporation as that term is defined
in the 1933 Act, (2) the offer of such securities was not made to a person in
the United States and either (A) at the time the buy order was originated, the
buyer was outside the United States, or the seller and any person acting on its
behalf reasonably believed that the buyer was outside the United States, or (B)
the transaction was executed in, on or through the facilities of The Toronto
Stock Exchange or the TSX Venture Exchange or any other designated offshore
securities market as defined in Regulation S under the 1933 Act and neither the
seller nor any person acting on its behalf knows that the transaction has been
prearranged with a buyer in the United States, (3) neither the seller nor any
affiliate of the seller nor any person acting on any of their behalf has engaged
or will engage in any directed selling efforts in the United States in
connection with the offer and sale of such securities, (4) the sale is bona fide
and not for the purpose of "washing off" the resale restrictions imposed because
the securities are "restricted securities" (as such term is defined in Rule
144(a)(3) under the 1933 Act), (5) the seller does not intend to replace the
securities sold in reliance on Rule 904 of the 1933 Act with fungible
unrestricted securities and (6) the contemplated sale is not a transaction, or
part of a series of transactions which, although in technical compliance with
Regulation S, is part of a plan or scheme to evade the registration provisions
of the 1933 Act. Terms used herein have the meanings given to them by Regulation
S.

Dated:   _____________________

                                       _________________________________________
                                       Name of Seller

                                       By: _____________________________________
                                           Name:
                                           Title:

<PAGE>



                                    EXHIBIT B

                        FORM OF LETTER TO BE DELIVERED BY
            ORIGINAL U.S. PURCHASER UPON EXERCISE OF OFFERED WARRANTS

SPECTRUM SIGNAL PROCESSING INC.
One Spectrum Court, Suite 200, 2700 Production Way
Burnaby, British Columbia
V5A 4X1

- and to -

Computershare Trust Company of Canada  as registrar and transfer agent
510 Burrard Street
Vancouver, British Columbia
V6C 3B9

Dear Sirs:

         We are delivering this letter in connection with the purchase of common
shares (the "Shares") of SPECTRUM SIGNAL PROCESSING INC., a corporation
incorporated under the laws of Canada (the "Corporation"), upon the exercise of
warrants of the Corporation ("Offered Warrants") issued pursuant to an
Indenture, dated as of March 23, 2004, between the Corporation and Computershare
Trust Company of Canada.

         We hereby confirm that:

         (a)      we are an "accredited investor" within the meaning of Rule 501
                  of Regulation D under the United States Securities Act of 1933
                  (the "U.S. Securities Act");

         (b)      we are purchasing the Shares for our own account;

         (c)      we have such knowledge and experience in financial and
                  business matters that we are capable of evaluating the merits
                  and risks of purchasing the Shares;

         (d)      we are not acquiring the Shares with a view to distribution
                  thereof or with any present intention of offering or selling
                  any of the Shares, except (i) to the Corporation, (ii) outside
                  the United States in compliance with Rule 904 of Regulation S
                  under the U.S. Securities Act or (iii) in a transaction exempt
                  from the registration requirements under the U.S. Securities
                  Act and any applicable state securities laws, provided that in
                  connection with any transfer referred to in clause (iii), a
                  written opinion of counsel reasonably acceptable to the
                  Corporation to the effect that such transfer is exempt from
                  the regulation requirements of all applicable United States
                  federal and state securities laws will be provided to the
                  Corporation;

<PAGE>

                                      -2-

         (e)      we acknowledge that we have had access to such financial and
                  other information as we deem necessary in connection with our
                  decision to purchase the Shares; and

         (f)      we acknowledge that we are not purchasing the Shares as a
                  result of any general solicitation or general advertising,
                  including advertisements, articles, notices or other
                  communications published in any newspaper, magazine or similar
                  media or broadcast over radio, television, or any seminar or
                  meeting whose attendees have been invited by general
                  solicitation or general advertising.

         We understand that the Shares are being offered in a transaction not
involving any public offering within the United States within the meaning of
U.S. Securities Act and that the Shares have not been and will not be registered
under the U.S. Securities Act. We further understand that any Shares acquired by
us will be in the form of definitive physical certificates and that such
certificates will bear a legend reflecting the substance of paragraph (d) above.

         We acknowledge that you will rely upon our confirmations,
acknowledgements and agreements set forth herein, and we agree to notify you
promptly in writing if any of our representations or warranties herein ceases to
be accurate or complete.


                                            ____________________________________
                                            (Name of Purchaser)


                                            By: ________________________________
                                                Name:
                                                Title:

                                                Address: