Seguí los pasos deesta, dado que tuve problemas para instalar cocoapods, descargué manualmente el zip del SDK, lo agregué al proyecto, lo compilé bien pero obtuve muchos errores de enlace como los siguientes. Gracias por cualquier ayuda.

Undefined symbols for architecture x86_64:  
 "_CBCentralManagerOptionShowPowerAlertKey", referenced from:
       l942 in GoogleMobileAds(flat-x86_64)   "_CVBufferGetAttachment", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_CVOpenGLESTextureCacheCreate", referenced from:
       l2399 in GoogleMobileAds(flat-x86_64)   "_CVOpenGLESTextureCacheCreateTextureFromImage", referenced from:
       l2400 in GoogleMobileAds(flat-x86_64)   "_CVOpenGLESTextureCacheFlush", referenced from:
       l2398 in GoogleMobileAds(flat-x86_64)   "_CVOpenGLESTextureGetName", referenced from:
       l2400 in GoogleMobileAds(flat-x86_64)   "_CVOpenGLESTextureGetTarget", referenced from:
       l2400 in GoogleMobileAds(flat-x86_64)   "_CVPixelBufferGetHeight", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_CVPixelBufferGetWidth", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_GLKMatrix4Identity", referenced from:
       l2392 in GoogleMobileAds(flat-x86_64)
       l2402 in GoogleMobileAds(flat-x86_64)   "_OBJC_CLASS_$_CBCentralManager", referenced from:
       objc-class-ref in GoogleMobileAds(flat-x86_64)   "_OBJC_CLASS_$_CBUUID", referenced from:
       objc-class-ref in GoogleMobileAds(flat-x86_64)   "_OBJC_CLASS_$_CMMotionManager", referenced from:
       objc-class-ref in GoogleMobileAds(flat-x86_64)   "_OBJC_CLASS_$_EAGLContext", referenced from:
       objc-class-ref in GoogleMobileAds(flat-x86_64)   "_OBJC_CLASS_$_GLKView", referenced from:
       objc-class-ref in GoogleMobileAds(flat-x86_64)   "_OBJC_CLASS_$_SFSafariViewController", referenced from:
       objc-class-ref in GoogleMobileAds(flat-x86_64)   "_glActiveTexture", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_glAttachShader", referenced from:
       _GADGLCreateProgram in GoogleMobileAds(flat-x86_64)   "_glBindAttribLocation", referenced from:
       l2399 in GoogleMobileAds(flat-x86_64)   "_glBindTexture", referenced from:
       l2400 in GoogleMobileAds(flat-x86_64)   "_glClear", referenced from:
       l092 in GoogleMobileAds(flat-x86_64)   "_glClearColor", referenced from:
       l092 in GoogleMobileAds(flat-x86_64)   "_glCompileShader", referenced from:
       l1011 in GoogleMobileAds(flat-x86_64)   "_glCreateProgram", referenced from:
       _GADGLCreateProgram in GoogleMobileAds(flat-x86_64)   "_glCreateShader", referenced from:
       _GADGLCreateProgram in GoogleMobileAds(flat-x86_64)   "_glDeleteProgram", referenced from:
       _GADGLCreateProgram in GoogleMobileAds(flat-x86_64)
       l2401 in GoogleMobileAds(flat-x86_64)   "_glDeleteShader", referenced from:
       _GADGLCreateProgram in GoogleMobileAds(flat-x86_64)   "_glDetachShader", referenced from:
       _GADGLCreateProgram in GoogleMobileAds(flat-x86_64)   "_glDisable", referenced from:
       l2399 in GoogleMobileAds(flat-x86_64)   "_glDrawArrays", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_glEnableVertexAttribArray", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_glGetProgramiv", referenced from:
       _GADGLCreateProgram in GoogleMobileAds(flat-x86_64)   "_glGetShaderiv", referenced from:
       l1011 in GoogleMobileAds(flat-x86_64)   "_glGetUniformLocation", referenced from:
       l2399 in GoogleMobileAds(flat-x86_64)   "_glLinkProgram", referenced from:
       _GADGLCreateProgram in GoogleMobileAds(flat-x86_64)   "_glShaderSource", referenced from:
       l1011 in GoogleMobileAds(flat-x86_64)   "_glTexParameterf", referenced from:
       l2400 in GoogleMobileAds(flat-x86_64)   "_glTexParameteri", referenced from:
       l2400 in GoogleMobileAds(flat-x86_64)   "_glUniform1f", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_glUniform1i", referenced from:
       l2399 in GoogleMobileAds(flat-x86_64)   "_glUniformMatrix3fv", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_glUniformMatrix4fv", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_glUseProgram", referenced from:
       l2399 in GoogleMobileAds(flat-x86_64)   "_glVertexAttribPointer", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_glViewport", referenced from:
       l092 in GoogleMobileAds(flat-x86_64)   "_kCVImageBufferYCbCrMatrixKey", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_kCVImageBufferYCbCrMatrix_ITU_R_601_4", referenced from:
       l2397 in GoogleMobileAds(flat-x86_64)   "_kCVPixelBufferPixelFormatTypeKey", referenced from:
       l086 in GoogleMobileAds(flat-x86_64)   "_kEAGLColorFormatRGBA8", referenced from:
       l070 in GoogleMobileAds(flat-x86_64)   "_kEAGLDrawablePropertyColorFormat", referenced from:
       l070 in GoogleMobileAds(flat-x86_64)   "_kEAGLDrawablePropertyRetainedBacking", referenced from:
       l070 in GoogleMobileAds(flat-x86_64) ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code
 1 (use -v to see invocation)