WHILE THE HIGH-POWERED network-television executives have been agonizing over the ups and down of another fall season, their colleagues in public broadcasting have won some important support for better noncommercial programming. In a comprehensive set of proposals sent to Congress this month, President Carter has moved to strengthen the state of public broadcasting through reorganization, better financing and a commitment to "increase public broadcasting's insulation from inappropriate political influence." If enacted, the White House legislation could do much to encourage the kind of talented, imaginative personnel - at local stations and on a national level - that the public system deserves.

In particular, the President's emphasis on increased programming indepedence for the public system is welcome, formal shift from pressures that were brought to bear on public broadcasting during the Nixon years. Then, though it didn't show up directly on your screens, there was a bitter internal conflict over control of the nation's public-television hookup of stations under the Public Broadcasting Service. When the Nixon White House expressed displeasure at the way public television was being run and at the content of public-affairs programs, the presidentially appointed Corporation for Public Broadcasting - which receives money from Congress and distributes it to National Public Radio and PBS for a matching at the local level - fought to takeover all programming and scheduling of TV.

The battle eventually ended in a delicate truce between CPB and PBS. But now President Carter is seeking an increase in federal funds to be appropriated under an advance five-year congressional authorization totaling nearly $1 billion - which is as much as has gone into the system since the federal government started putting in money 10 years ago.

The Carter plan also could double the money for improved equipment at the local level, which is key to any increase in local stations' initiative and independent operation.

As the President noted, "Because it is free of the scramble for ratings, public broadcasting has room for experimentation and risk-taking . . . It can meet the needs of audiences that number in the millions but are seldom served anywhere else." To reduce the opportunities for political interference by the government in programming, the White House measure would 1) phase out four presidentially appointed members of the 15-member CPB board and replace them with members chosen by public-television and radio licenses and 2) remove CPB from decisions on individual programs.

Thus, PBS would have control of national public-television programming, and there would be a "in the CPB's current staff and any overlapping duties it now performs.

There are some doubters, of course, who see the plan as a way of turning public television into a "fourth network" fully competitive with commercial television. While we don't think that's necessarily bad, the existence of a strong, independent PBS network can also set some glittering examples for commercial television as it has already with programs such as "Sesame Street," the "MacNeil-Lehrer Report," coverage of congressional hearings and the past interpretive efforts of William Buckley, Bill Moyers, Elizabeth Drew, Paul Duke and many more.

Obviously no legislation can guarantee viewers and listeners a permanent season of high-quality, stimulating, controversial and innovative programming on their local stations, but with approval of President Carter's sensitive proposals, a much healthier public broadcasting environment could surely foster a constructive (and instructive) alternative use of the public airwaves.